All About Irises All About Irises Dutch Irises All Kinds of Irises: They're Easy, Dependable, and Bring the Goddess of the Rainbow into Your Garden By Ray Allen, Founder of AmericanMeadows.com With about 200 different species scattered worldwide, gardeners probably know fewer of these flowers than any other popular group. It's all because of the intense interest in just a few of the species, for centuries. Today, of course, everything is dominated by our oversized, “bigger is better” passion for the tall Bearded Iris , also called German Iris (Iris germanica) . Anyone who studies Greek mythology learns that Iris is the name of the Goddess of the Rainbow, surely one of the best assignments on Olympus. And because of the great elegance of the iris bloom, it has been the symbol of monarchs and royal families throughout history. In fact, one of the earliest known artworks of an iris is a fresco in King Minos' palace on the Greek Island of Crete. The palace dates from 2100 BC. Of course, the most famous royal use of the iris as a symbol of power and position was that of the Bourbon Kings of France, including Louis XIV.

The iris was adapted on royal banners as the “Fleur de Lys”, the elegant, three-sectioned symbol that disappeared from the French flag with their Revolution, but is still quite common in the decorative arts. In fact, today it still proudly adorns the beautiful flag of the French-founded Province of Quebec in Canada. The famous "Fleur de Lys" is an ancient graphic representation of the Iris bloom. It was used as the symbol of French royalty for centuries. Great Britain also borrowed the motif. Edward III added the iris to his royal coat of arms during the 14th Century. And a famous painting of Elizabeth I shows her in a gown embroidered with irises . Irises also have a medicinal history, the roots being used in preparation for medicines for skin infections, syphillis, dropsy and stomach problems. Today, it is still a drug widely used to purge the liver. The Iris in Art The iris has probably second place as the favored flower in great art. After the rose which is surely No.

1, irises appear in paintings by Leonardo daVinci, Durer, Renoir, Cezanne, van Gogh, (whose famous painting “Irises” set an all-time auction price in recent years, selling for over 53 million dollars), Gauguin, and of course, Claude Monet. Growing Bearded Irises Bearded Irises have been popular forever, and no wonder. They are very easy to grow, and, especially in recent years, put on one of the truly great flower shows in the garden. Bearded Iris bloom is in “late spring,” after the tulips and daffodils , and often with oriental poppies and peonies . There are six official classifications of Bearded Irises , based mostly on their heights, but the one everyone is interest in is called, not surprisingly, “Tall Bearded Irises.” They grow from 27 to 41 inches tall. And the spectacular flowers measure from 4 to 7 inches across. Unlike many other perennials , Irises are happy to bloom lavishly over a very wide area of North America.

They are hardy into Canada, and are equally beautiful in gardens in places like Dallas, Texas, and even further south. They are famously easy to grow, and are some of the most persistent perennials of all. Like oriental poppies , they will withstand grass, weeds, and other plants, even if a perennial garden is untended for years. You may well see an old garden with almost nothing left but the weeds, and often there, sticking up out of the tough invading grasses and brush are the healthy sword-like leaves on an iris . The Bearded Irises . These are examples of the most popular irises - the large-flowered tall ones that are planted in late summer. The popularity of these, with thousands of varieties and hybrids available, tend to overshadow the wonderful "Beardless" irises discussed below. Bearded Irises are also called " German Irises ." Bearded Irises grow from a root called a rhizome, an enlarged, elongated sort of lumpy bulb-like affair that is often right on the surface of the ground. In fact, Bearded Irises like to have their rhizomes somewhat “exposed,” usually running along like a sausage half buried in the soil.

These rhizomes multiply horizontally, forming new sections and finally, a mat of rhizomes from which rise the beautiful fans of leaves and spectacular flowers. Division is Important — and easy. This is another characteristic Bearded Irises share with their blooming companion, oriental poppies . Both must be divided every few years. Both form larger and larger colonies, and as the colonies become thick and leafy, there is less and less bloom. Dividing irises is easy, and should be done after bloom. Simply dig up the whole mass of roots, and cut the rhizomes apart with a sharp knife. Then replant them, either singly, or maybe in small clumps a few inches apart — and transfer your “extras” to other parts of the garden. These newly planted irises will have time to grow and establish themselves for the rest of the summer and fall, and will be ready to bloom for you next spring. An old clump of bearded irises will yield enough tubers to create a whole new garden of irises , if that's what you want. Plant each rhizome or rhizome group with the top of the rhizomes showing atop the soil, and keep the area moist for a few weeks.

They'll quickly send down their roots in the new locations. The Rainbow of Varieties grows every year. Today, there are thousands and thousands of Tall Bearded Iris hybrids, with new ones every year. Before World War II, most new hybrids came from Europe, but since, it has been an American passion. Today, the trade is led by the famous Shreiner's Iris Nursery in Oregon and others. But of course there are other Bearded Iris experts and hybridizers all over the world. Growing Beardless Irises Japanese Iris First, let's dispel the confusion that surrounds this group: Once they were known as Kaempferi Irises, today many call them "The Butterfly Irises", but the correct common name is simply " Japanese Iris ." In luscious colors of purple, pink, and endless bicolors, they have been cultivated in Japan for over 500 years, and were once restricted to enjoyment by royalty only. Though many think they are, they are not water dwellers. They require about the same conditions as ferns, astilbes or impatiens—just moist ground, which most all gardeners can easily provide.

As you can see by the photos, these iris blooms are quite different from the tall "stand-up" flowers of the big Bearded Irises . With Japanese Irises , both sets of petals are more flat, forming a simpler, flatter—and many think more beautiful—flower. Japanese Irises form large lavish hardy clumps and are highly decorative. They're also great for cutting. Siberian Iris This is the iris favored by many landscapers over the Bearded group. And the reason is obvious. Hardy as oaks, Siberian Irises form very handsome clumps of grass-like foliage with a host of blooms rising on elegantly thin stems. The flowers are smaller than the Bearded Iris blooms, but once they're gone, the foliage of this group remains a highlight in the garden all season long, as decorative as almost any ornamental grass . Siberian Iris' hardiness and longevity are also big plusses. Once established, they will grace a garden for generations. There are fewer hybrids here, compared to the Bearded group, but there are now some quite glamorous bi- and tri-colors. Still, purist gardeners usually prefer the classic blue, purple and yellow flowers from this elegant group.

They can be planted in spring or fall. Louisiana Iris One of the most under-used groups in gardening, these magnificent irises are our own native plants'spectacular wildflowers from the bayous and wetlands of the Gulf Coast. The have large flowers, often from 4 to 6 inches across, and a form more like the Japanese type's flatter and wider than the tall up-and-down Bearded Iris bloom. The hybrids of these beauties are often hardy all the way to Canada, so gardeners almost everywhere can enjoy them now. They enjoy conditions similar to the Japanese types, so all you need is a moist area, rich soil, and partial shade. Any well-watered partially-shaded perennial garden will do. This group is world famous for its large flowers and wide palette of coloring, featuring some colors found in no other group. The dark ' Black Gamecock ' is known everywhere, and the Louisianas are justly famous for the very dramatic markings, called 'flashes' of gold in their centers, clearly seen in the famous, ' Sinfonietta '. Wild Iris Many of the 'species' or wild irises are among the Spring-Planted beardless group.

The two best known are our own Wild Iris, ' Blue Flag ' so common and loved in the Northeast. And the taller 'Yellow Flag', native to England. The Blue Flag is a perfect plant for your wildflower meadow, or anyplace else in your landscaping where there is plenty of water in spring. They cannot be submerged, but enjoy wet meadow and wet woodland locations. The very strong-growing Yellow Flag is also useful, but be aware that it can be invasive, and end up choking shallow waterways, much like cattails. Be sure it is not considered a pest in your area before planting. The Beardless Group includes pretty much the rest of the irises , and that means several kinds: most importantly Japanese , Siberian , Louisiana , and certain Species (or Wild) Irises. As you can tell by the names, beardless irises occur worldwide. They also require certain growing conditions. No pond or stream necessary: This photo shows the happy combination of Japanese Irises with astilbes , daylilies and other perennials . No pond or stream in sight.

The misconception about “Water Iris” You may have heard that many of the beardless irises are “pond irises” or “water irises”, and that's because many of them can actually grow in shallow water. But that is not a requirement. Certain Japanese Irises , Louisiana Irises , and many of the Wild Irises love moisture, but none of them must be planted actually in the water. If you have a pond or steam, they'll love that location, but most people don't. And all these plants are perfectly happy in a well-watered perennial garden. Just give them locations where they'll get plenty of moisture throughout the season. The one big exception in the group are the Siberians . They like moisture too, but are perfectly happy with normal perennial conditions, and don't resent drying out from time to time. Mulching Spring-planted Irises, Sun/Shade, and Companion Plants Mulching is important with this group. Since most of them enjoy the same moist, partially-shaded conditions as hostas , ferns , astilbes and impatiens, mulch their roots to help them retain moisture during warm dry periods. Bark chips, peat, or any good moisture-retaining mulch will be a big help.

Full sun is ok, too, but no irises should be in blazing hot dry areas. Fertilizing Spring-planted Irises They need no more than the usual feeding, like most flowering perennials . For feeding perennial gardens, my favorite perennial expert, Frederick McGourty, recommends familiarizing yourself with standard perennial flower fertilizers, which are always labeled with three numbers in a sequence, such as 5-10-5 or 5-10-10, or 10-10-10. These numbers on the bag refer to percentages of Nitrogen, Phosphorus and Potassium, in that order. McGourty explains that the most important element here for flowering plants is the middle number, Phosphorus, so he recommends choosing a fertilizer with the middle number no lower than the other two. If your garden is new, try to rake in your fertilizer a week or two before planting. And in later years, one feeding in spring (remove the mulch, and rake it in) should do. If you use dry granular fertilizer, remember to scatter it when the soil is wet and the foliage of your plants is dry. Dry fertilizer sticking to stems and leaves can burn the plants.

If you're new to the neighborhood, it's always good to give your local county extension agent a call, and discuss soils and feeding with him or her. That's what they're there for. It's great local advice, and it's free. You'll find the number in the phone book under US Govt, Cooperative Extension Services. Dividing Spring-planted Irises These irises have a variable root structure, but all are quite obvious when it comes to dividing. Of course, you may never choose to divide yours. If you're like me, you love large expanding clumps of Siberian Iris , for example. I've never seen the size of the clump interfere with the bloom. And the incredible photo of that purple Japanese Iris at the top of this page proves that an older, larger clump of that iris blooms just beautifully. But you may choose to divide. If you do, just after bloom is a good time, since then your divides will have the season to regrow and prepare for next summer's flowering. As with all dividing, try to keep your clumps large; don't reduce your plant to little bits that will take years to grow back to blooming size.

If your iris root is a mass of rhizomes (like Blue Flag will be), simply cut them with a sharp knife, leaving several rhizones per clump. But most of this group will have a mass of fleshy roots, similar to daylilies . A sharp spade will do the trick, and to disturb the growing plant as little as possible, you may do what I do. For a Siberian for example, don't dig it up. Just sink the spade directly down in the middle of the clump and cut straight through the roots. Then pry up one of the halfs, take it out of the ground, and then fill in the hole. Your undisturbed half will then be very little affected by the whole operation. Then take your removed half, chop it into (large) pieces and plant them. Water before and after all this, and you should have no problems. It's really easy. If your clumps are large, though, it can be heavy work. Wintering Spring-planted Irises One of the names says it all: Siberian Irises are as hardy as oaks, and really need no winter cover or care. Blue and Yellow Flags are the same.

Japanese Irises are much the same, too but some hybrid varieties may need some winter protection. Louisiana Irises are the ones to watch when it comes to winter hardiness. Since they're from the Gulf Coast area, some are hardy only a few zones north. However, many of the most popular hybrids have been bred for hardiness all the way into Canada. So when you choose yours, check the hardiness of your favorites. Growing Bulbous Irises 'Sapphire Beauty' Dutch Iris Still other irises are the ones that grow from bulbs , as easy to plant and grow as a tulip . The common ones are called Dutch Irises , and their bulbs are small, about half the size of a tulip bulb . (Photo at right is the famous Dutch Iris named 'Sapphire Beauty.' ) These are the florist's favorite, and if you ever order a “Spring Arrangement” from a flower shop, you can bet these will be in there. They're the really beautiful irises on long, thin stems in the familiar blue with the bright flash of yellow, but also in reds, whites, yellows, and bicolors.

Whenever you buy tulips or daffodils for fall planting, be sure to also get some " Dutch Iris ." They're usually listed in bulb sales under "other bulbs" or "minor bulbs." They're amazingly inexpensive, and you'll love them in spring. Iris Flower - Varieties and Types of Iris | TheFlowerExpert Tall Bearded Iris Blue Flag Iris Bulbous irises grow from bulbs that require a period of dormancy after they have bloomed. The bulbous irises are typically smaller than rhizome irises and usually produce smaller blossoms. from our stores - Pickupflowers - the flower expert Growing Irises Before planting Iris, improve the soil conditions by using a slow release fertilizer. To increase the organic matter content, use compost, peat moss or well-rotted manure. Fertilizer and organic matter should be worked thoroughly into the top 4 to 6 inches of soil. Wooded areas with good drainage and partial shade are ideal spots for the crested iris. Irises are grown from both seed and root separation. The roots or rhizomes, are easily separated and replanted. The rhizome looks like a long, thin potato with roots underneath.

When transplanting, separate the rhizome. Make sure to have some root and a leaf or two in each section. Plant the rhizomes near the surface with the roots below. Divide the clumps and plant single rhizomes, spacing them 8 to 18 inches apart according to the effect desired. Spade a planting hole about 10 inches deep and work 1 tablespoonful of fertilizer into the soil in the bottom of the hole. If the soil is heavy, some drainage material such as gravel or broken pottery should be placed in the hole. Fill the hole with loose soil and place the root section so that it will not be covered more than 1 inch deep. Most Beardless Irises can also be propagated from seeds. The Dykes Medal is awarded annually to the finest iris of any class. Tall bearded irises have won the Dykes Medal more often than any other class. Iris Plant Care Apply a thin layer of compost around the base of plants each spring, leaving the rhizome exposed. As flowers fade, cut back the flower stalks to the base of the plant. To encourage a second bloom on re-blooming varieties, promptly remove faded flowers and maintain consistent watering throughout the summer.

In autumn, trim away dead foliage and prune back healthy leaves to a height of 4 to 5 inches. Once the soil has frozen, apply a layer of mulch to help prevent roots from heaving out of the soil during alternate freezing and thawing. If heaving occurs, don't try to force plants back into the soil. Instead, cover rhizomes and exposed roots with soil. Divide bearded irises every 4 to 5 years, preferably in late summer. Each division should have one or two leaf fans. Older rhizomes that have few white feeding roots should be discarded. Want to learn more about growing Irises and other flowers? View books on Gardening Other Uses of Iris The juice of the fresh roots of Iris, bruised with wine, has been employed as a strong purge of great efficiency in dropsy. Iris roots are used to treat skin diseases. The juice of Irises are also sometimes used as a cosmetic for the removal of freckles on the skin. The fresh root of the Iris germanica is a powerful cathartic, and for this reason its juice has been employed in dropsy.

It is chiefly used in the dry state, being said to be good for complaints of the lungs, for coughs and hoarseness, but is now more valued for the pleasantness of its violet-like perfume than for any other use. Iris flowers are used as a liver purge. Purple Iris Purple Iris Flowers bloom for two to three weeks in the late spring to early summer. The Purple Iris is the state flower of Tennessee. The Purple Iris can be grown in your home, in containers. The majority of Iris flowers are in Purple. Also have a look at some other Flowers Iris : Yard and Garden : University of Minnesota Extension University of Minnesota Extension Iris Rhonda Fleming Hayes and David C. Zlesak The dazzling beauty of the iris is captured in the paintings of Monet and Van Gogh, yet this adaptable perennial is no diva. It is not unusual to see irises still blooming on abandoned farmsteads. Hardy and vigorous with flamboyant flowers, the iris has been a mainstay for gardeners throughout the years for good reason. Bearded iris are known for their large colorful blooms.

Sound horticultural advice says “right plant for the right place”; picking from the myriad choices of iris varieties and cultivars, there are irises for just about every garden situation. Selecting for a sequence of bloom times, it is possible to extend the iris season from spring to early summer, with even an encore from re-bloomers. It is important to note that these old-fashioned flowers now serve a contemporary use in the setting of rain gardens, water gardens, or xeriscapes, depending upon the variety and its cultural needs. Two main types of iris do well in northern climates; bearded and Siberian. However there are less common species worth investigating and growing such as Iris reticulata (dwarf or Dutch iris), I. pallida (sweet iris), I. pumila (dwarf bearded iris), I. cristata (dwarf crested iris), and the shade tolerant I. tectorum (Japanese roof iris). Bearded iris have swollen rhizomes that grow at or near the soil surface. Bearded iris Bearded iris has a tan colored, tuberose rhizome that acts as a food-storage unit for the plant.

Lying just at the soil surface, the rhizome sends roots downward while the shoots with sword-shaped leaves grow upward. As the leaves multiply, they fan out until a flower stem or scape emerges from the growing point and produces the spectacular flowers. The classic bearded iris is blue or purple with yellow markings at the center, however they also come in white, lavender, yellow, peach and bronzy reds with different combinations of marking and veining, as well as ruffling. The elegant petals of the bearded iris serve very practical purposes. The upright petals or standards act as colorful flags to attract pollinating insects, while the downward curving petals or falls, function as a landing pad for them. The yellow blotches and veining work like a map that directs the insect to the nectar. While the distinctive, fuzzy beard attached to the falls helps the pollinators to hang on once there. Bearded iris have whisker-like protrusions on their petals. Best location for bearded iris Bearded irises thrive in full sun with plenty of room for good air circulation. Crowding or shading by other plants can impact blooming as well as contribute to disease.

Irises grow best in rich soil that has been amended with organic matter such as compost, aged manure, or peat. Well-drained soil is important to avoid root rot of the fleshy rhizome. Best care for bearded iris Plant selection Iris rhizomes are typically available at nurseries and garden centers in July to August. Mail-order purchases are shipped at this time as well. Rhizomes should be firm and fresh; it is possible to trim off broken or damaged portions of otherwise healthy specimens. Potted irises are available in the spring in limited varieties. Planting Although the iris rhizome is planted in a shallow hole, the soil should be loosened to a depth of 10 inches to allow for optimum root growth. Place the rhizome so that it sits barely under the soil, firming the soil around it, and then water it in. Potted iris can be planted in the spring using care to plant at the same soil level as in the pot. Containerized iris are often available in spring at local garden centers. Water Bearded iris should be kept consistently moist but only from spring until the end of flowering.

After blooming the plant enters a period of-semi-dormancy when too much water can actually cause rot. This watering pattern corresponds with that of a xeric garden, taking advantage of spring rains, followed by summer dryness, making the bearded iris an attractive candidate for the low-water landscape, or well drained to drier soils. Mulch Mulch should be used sparingly around bearded iris during the growing season; especially after bloom when a dry period is needed. Avoid mulch in or around the crown to reduce the chance of rot. Winter protection to protect from frost heaving with mulch however is important, but only after the ground freezes. Fertilizer Fertilize bearded iris in early spring if a soil test shows that you need to add nutrients. As growth emerges, use a low nitrogen fertilizer watering it in well; and then fertilize again when the flower stem appears. Organic fertilizers like compost, blood meal, or fish emulsion can also be used. For more information on fertilization please click here . Best cultural practices for bearded iris Pest and disease control Damage is caused by iris borer.

Michelle Grabowski Good cultural practices can help to reduce the incidence of iris borer, the most common and serious problem with bearded iris. It is the iris borer larvae which cause damage; they attack the central leaf stalk and tunnel downward into the rhizome, where they pupate and emerge as an adult moth. Gardeners can physically remove them from the leaves and rhizomes or use an insecticide. Keep beds clear of weeds and debris to avoid harboring the next generation of iris borer eggs. For more information on iris borer and other pests please click here . Some irises with large heavy blooms and taller stems benefit from staking; use a thin bamboo or metal stake next to the plant and soft ties to attach them. Removing spent blooms stops the formation of seed pods as well as making the iris bed more attractive. Once the entire flowering stem is finished blooming, cut it off at the base. It is a good idea to remove iris foliage showing disease or insect damage. Irises should be trimmed back carefully, leaving as much green, healthy leaf tissue as possible. This runs contrary to past suggestions to cut back the entire plant.

In reality, next year’s health and vigor is determined by the ability to make and store food during the current season; the more leaves the better. Yellowed leaves can be pulled completely off without harming the rest of the plant. Any dead plant material should be discarded to prevent disease and insect problems. The time to cut back and discard all foliage is after a hard frost. In spite of their hardiness in freezing weather; growing close to the soil surface, iris rhizomes can heave during temperature fluctuations. A six inch layer of mulch, such as chopped leaves or straw will help protect plants from repeated cycles of freezing and thawing. Plants can become crowded over time and benefit from dividing. Division Dividing bearded iris is vital to the plant’s health and makes iris a relatively higher maintenance perennial than others. A decrease in bloom can indicate overcrowding and the need to divide bearded irises; this is generally done every 3-4 years. The best time to divide iris is four to six weeks after blooming, in July to early August, when the plant is semi-dormant. This will give the plant ample time for re-establishment in order to insure flowering the next season.

First cut the foliage fan back to three to six inches to prevent water loss, removing dead or yellow leaves as well. Dig up the rhizomes and cut them apart into 3-4 inch sections with a sharp knife, saving the healthy outer growth connected to the current stem tissue. The roots can be trimmed back to two inches. If disease has been a problem in the iris bed, the rhizomes can be treated with a fungicide labeled for iris before replanting. Plant the new divisions following the same bare root instructions (see above) with attention to proper spacing for good air circulation. Leftover plant pieces and debris should be discarded. Creative landscaping with bearded iris Use the vertical, spiky leaves of iris to contrast with mounding, finer leaved plants in the perennial garden. Plant early blooming iris with spring flowering bulbs; late blooming types with perennials such as Aquilegia spp. (columbine), Hemerocallis spp.(daylily), Heuchera spp. (coral bells), Nepeta spp. (catmint), Leucanthemum spp. (shasta daisy), and Salvia spp. (sage).

Include bearded iris in the cutting garden; although not long lasting, iris blooms are fragrant, striking cut flowers, the seed pods can be used in arrangements as well. Siberian iris Breeding work over the past couple decades have greatly expanded the color range available in Siberian iris. As their name of origin implies, Siberian Irises are tough and hardy. They are sometimes known as the beardless iris. Growing from fibrous roots into tall, grassy clumps of slender leaves, the flowers unfurl without the beard but are no less beautiful. They come in various shades of blue, lavender, white, or yellow. After blooming in late spring to early summer, the foliage remains attractive throughout the season. The vase-shaped clumps multiply effectively almost as a groundcover crowding out weeds. Best location for Siberian iris For most prolific bloom, Siberian Iris should be planted in full sun. Siberian irises flourish in rich, slightly acidic (pH 5.5-6.5), high organic matter soil. These iris have a high tolerance and actually a preference for moist to wet soils. Best care for Siberian iris Planting Bare root stock is available in late summer to early fall.

The plants should be removed from their packaging promptly and soaked overnight prior to planting. They should be planted with the crown just under the soil surface, then watered in. Potted varieties are available in the spring; they should be planted carefully at the same depth as in the pot and watered in well. Siberian iris prefer full sun to light shade, excess shade can reduce or even eliminate flowering. Siberian iris prefers full sun to part shade. Water Siberian Irises need a lot of water; consistent moisture throughout the season with occasional deep watering will help them to perform at their best. In well-drained soil it is difficult to overwater them. Mulch Organic mulches such as compost, shredded leaves or pine needles help to conserve soil moisture while blocking weed growth. Fertilizer If a soil test shows a deficiency, fertilize with a granular commercial fertilizer in early spring as new growth appears and then again just before bloom. Water soluble and organic fertilizers such as compost, aged cow manure, blood meal or fish emulsion can also be used. For more information on fertilization please click here .

Best cultural practices for Siberian iris Pest and disease control Siberian irises are rarely bothered by pests; occasional infestation of aphids can be controlled by spraying off with the hose or using an insecticidal soap. The organic gardener will appreciate their high disease resistance. Mice will sometimes nest in the foliage over winter, trimming the leaves back after frost will make this less attractive to them. Siberian irises are deer-resistant. Pruning and grooming Siberian iris form dense clumps. Removing spent blooms stops the formation of seed pods and energy to be diverted to the plant instead. However, the seed pods of Siberian iris are attractive and on established plants can be left for added fall and winter interest. If one decides to prevent seed pods from forming, remove the entire flowering stem after it is finished blooming by cutting it off at the base. Division There are two opportunities or dividing Siberian Iris. To insure flowering it is best to divide in early spring as new growth just appears. Waiting until the new growth has started may stress out the plants and prevent them from flowering that season. Dig up the clump and cut through the thick root system, keeping at least six growing points with adequate roots in each clump.

Keep these sections moist, plant immediately, and then water in thoroughly. In late summer or early fall it is possible to cut back the foliage to about six inches, then dig and divide the plant as before. Replant, water in, and mulch well for winter survival. Siberian iris don’t require division as often as bearded iris to perform at their best; their tough crown often requires a strong arm to cut them apart. Dwarf crested iris. Creative landscaping with Siberian iris Plant in drifts along a stream or ponds for a more, natural looking garden. Plant in masses for dramatic effect. Plant with fall color in mind, Siberian iris foliage turns golden late in the season. Japanese roof iris Consider Siberian irises for the cutting garden, both the flower and seed pod can be used. More irises to consider Iris cristata or dwarf crested iris blooms in mid to late spring appearing almost stemless at just six inches tall. It tolerates soils with low fertility. Iris pumila or dwarf bearded iris blooms in mid spring and like dwarf crested iris is about 6” tall. Iris ensata or Japanese iris bears an upward facing flatter version of iris flower.

It thrives in damp, acidic soil. Typically hardy to zone 5. Iris pallida ‘Variegata’ has striking foliage striped with gray-green and pale yellow to cream. Iris pseudoacorus or yellow flag grows as a bog plant. Typically hardy to zone 5. Iris reticulata or dwarf Dutch iris blooms in early spring. A favorite for rock gardens, it is typically hardy to zone 5 and often forced as a spring flowering bulb in mixed bulb containers. Iris tectorum, sometimes known as Japanese roof iris, was grown on thatched roofs in Japan. It grows in damp to wet soil and will naturalize and tolerate more shade than other irises. Produced by Communication and Educational Technology Services, University of Minnesota Extension. Irises: How to Plant, Grow, and Care for Iris Flowers | The Old Farmer's Almanac Rate this Article: Average: 3.8 (355 votes) The tall, beautiful iris, named after the Greek goddess who rode rainbows, comes in many magical colors. Every gardener wants this perennial. Despite its divine origins, it is hardy, reliable, and easy to grow.

Irises also attract butterflies and hummingbirds and make lovely cut flowers. There are some 300 species in the genus Iris. The most familiar irises are the tall (at least 28 inches) bearded irises (Iris germanica). The distinctive flowers have three large outer petals called “falls” and three inner upright petals called “standards.” The falls may have beards or crests. Bearded iris are so-called because they have soft hairs along the center of the falls. In crested iris, the hairs form a comb or ridge. Most irises flower in early summer. Some, mostly bearded hybrids, are remontant, flowering again later in the summer. Planting Irises need at least half a day of sun and well-drained soil. Without enough sun, they won’t bloom. They prefer fertile, neutral to slightly acidic soil. If your soil is very acidic, sweeten it with a bit of lime, and forbear summer watering, which can lead to rot. Bearded irises must not be shaded by other plants; many do best in a special bed on their own. Soil drainage is very important.

Loosen the soil with a tiller or garden fork to a depth of 12 to 15 inches, then mix in a 2- to 4-inch layer of compost. Plant iris in mid- to late summer. Bearded irises have rhizomes (fleshy roots) that should be partially exposed, or thinly covered with soil in hot climates. Plant rhizomes singly or in groups of three with the fans outermost, 1 to 2 feet apart, depending on the size. Dig a shallow hole 10 inches in diameter and 4 inches deep. Make a ridge of soil down the middle and place the rhizome on the ridge, spreading roots down both sides. Fill the hole with soil and firm it gently. Water thoroughly. When planting, top-dress with a low-nitrogen fertilizer, and again in early spring. Care Avoid applying high-nitrogen fertilizers to the surface or carelessly mulching with organic matter, which may encourage rhizome rot. Keep rhizomes exposed. Unlike bulbs, which thrive deep underground, iris rhizomes need a bit of sun and air to dry them out. If they’re covered with soil or crowded by other plants, they’ll rot.

Irises may benefit from shallow mulching in the spring. Don’t trim iris leaves. Leaves carry on photosynthesis for next year’s growth. Cut off brown tips—and cut the flowering stalk down to the rhizome to discourage rot. If iris foliage is hit with heavy frost, remove and destroy it to eliminate borer eggs. After 2 to 5 years, when clumps become congested or lose vitality, divide and replant sound rhizomes in fresh soil. The best time to replant irises is soon after bloom. Transplant them to places where they will have “wet feet but dry knees.” Pests/Diseases Irises are deer-resistant and drought-tolerant. However, they are susceptible to borers, so check the rhizomes (fleshy roots) yearly for holes, discarding any infested ones. Verbena bud moth, whiteflies , iris weevil, thrips , slugs and snails, aphids , and nematodes may also be troublesome. Recommended Varieties ‘Immortality’ is a tall bearded flower that offers pure white flowers and reblooms in the fall. Grows best in Zones 4 to 9.

Other rebloomers, hardy at least to Zone 4, are: ‘Feed Back’, a dark purple; ‘Earl of Essex’, also purple; and ‘I Do’, with white flowers. If you live in Zone 5 or warmer, try ‘Jennifer Rebecca’, a mauve pink beauty. ‘ Siberian Irises ’ also come in a range of colors and are distinct from the more common bearded irises. Wit & Wisdom The iris is the French royal standard fleur-de-lis and also the symbol of Florence, Italy. Oral root, taken from the dried roots of Iris ‘Florentia’, was considered a cure for blood and lung diseases, and teething babies were encouraged to gnaw on a “finger” of dried root for its natural fluoride. Understanding the Types of Bulbs in Your Garden | Today's Homeowner Understanding the Types of Bulbs in Your Garden By: Julie Day Daffodils and Hyacinths, two early signs of spring, are examples of true bulbs. When most gardeners talk about “bulbs,” we are generally referring to a group of plants known as geophytes. Simply put, geophytes are plants with underground storage organs.

These underground organs contain food and energy for the plant’s life cycle. Geophytes tend to be herbaceous, which means that they go through a cycle of putting out leaves, blooming, dying back to the ground, and going dormant until the next growing season. There are actually five types of geophytes: True bulbs tubers tuberous roots The different structures are important to gardeners because they affect how the bulb is planted, how it grows, and how it reproduces. Here’s what you need to know about the different types and how they grow. True Bulbs A narcissus bulb has a flat basal plate, sprouting top, and papery outer covering. True bulbs are rounded, with a flat bottom (called a “basal plate”) that produces roots, and a top that produces the stem. They grow vertically and must be planted right-side up. Bulbs have layers (think about onions), and if you slice a true bulb right down the middle, you’ll find an immature flower and leaves tucked in there, surrounded by layers of food. Bulbs can be subclassified into tunicate (with a dry papery outer covering) and nontunicate (scaly).

Nontunicate bulbs are more fragile when transplanting. True bulbs reproduce by creating smaller bulbs (called “offsets” or “bulblets”) attached to the parent bulb. These can be separated and planted to produce more plants. Examples of true bulbs include: Tulip Corms Gladioli are examples of corms. On the outside, corms look a lot like bulbs. The difference is that they are actually the fattened base of the stem itself. A corm doesn’t grow in layers or have an embryonic bud at the center – it’s purely a solid-textured food supply for the stem above. As the plant grows and blooms, it consumes the food in the corm, and the corm shrivels and dies. Meanwhile, it has produced new, baby corms (called “cormels”) next to it, which sprout next year and can be transplanted to propagate the plant. Examples of corms include: Tuberous Roots Dahlias are examples of tuberous roots, usually growing in clumps. Tuberous roots look very similar to tubers but are actually swollen roots, not stems. They don’t have eyes.

Instead, tuberous roots often sprout at one end (called the “crown”) and grow in clumps, so a large flowering plant may have multiple tuberous roots radiating out from a sprouting “crown.” The plant sprouts from the base of the old stem, not from the root. Propagating tuberous roots is trickier, because many of them will only sprout if the divided section contains adequate crown tissue. Examples of tuberous roots include: Sweet Potato Anemone (some types) Tuberous Begonia Botanically speaking, geophytes can be sub-classified in great detail. For example, tuberous begonias are actually subclassified as an “enlarged hypocotyl,” because the enlarged part technically isn’t a root, it’s the area just above the root. The location of growth nodes and other details of the plant anatomy allow for near-endless categorizing and become more important if you get into the business of plant cultivation and development. For gardeners interested more in growing and enjoying these plants, the major differences between the five main types—bulb, corm, rhizome, tuber, and tuberous root—are the most important.

Tuberous begonias are another colorful example of an “enlarged hypocotyl.” American Iris Society :: Iris Pests and Diseases Pests and Diseases (contributions by Jim Morris) Diseases John Weiler, an iris hybridizer and long-time professor at Fresno State University in California, wrote in The World of Irises: "Irises are free of diseases and easy to grow!" "How many times [has] that statement been made by an enthusiastic writer in a magazine article, gardening book, or newspaper [?]. In recent years, though, as more gardeners have developed iris plantings and collections have expanded, the prevalence of several iris diseases has become more obvious." Irises’ susceptibility to various pests and diseases often depends on your geographic location and many diseases may or may not affect your irises. Keeping your garden clean from debris goes a long way toward avoiding the conditions conducive to both pests and diseases. Bacterial Leaf Blight (also called Bacterial Leaf Spot) Many iris types are affected by Bacterial Leaf Blight. The pathogen is Xanthomonas tardicrescens. Bacterial Leaf Blight causes large irregular spots that first appear near the margins on the leaf tips.

At first, the spots are just small pale areas. The key to diagnosing bacterial infections is that the spots appear watery at first, then soon turn light brown. These brown spots become larger and develop whitish or grayish centers. The bacterial infection follows the leaf veins down the leaves and the splotches may run together. This bacterial disease is easily confused with fungal leaf spot disease. Both occur during foggy and rainy weather. Irises will get bacterial leaf spot most often during mild weather, while fungal leaf spot can occur anytime the temperature is above freezing. Bacterial leaf spot splotches are larger and more irregular than fungal leaf spots. (see Fungal Leaf Spot below) Since there is no known cure, prevention is the only thing that will help control this disease. The bacterium is easily spread on garden tools as well as by water splashing on the plants, so beware of using any tools on healthy plants that have been used on infected plants. Wash your hands thoroughly after working on plants infected by bacterial leaf spot. Disinfect tools with a dilute solution (1 part bleach to 9 parts water) of 0.5 percent sodium hypochlorite (household bleach).

Cultural measures to prevent bacterial leaf spot include removing old foliage from the garden in the fall and destroying it. This will minimize a number of potential iris problems. Since the bacteria do not infect the rhizome, transplanting can be helpful. Fungal Leaf Spot Fungal Leaf Spot presents as small circular to oval spots on the leaves, turning yellowish to brown and often developing a distinct red-brown border. The pathogen is Didymellina macrospora. It can affect all bearded irises, Siberians, I. versicolor and the xiphiums, known as Dutch irises. The more rain you have the more prevalent it becomes. It is easy to control with the use of a fungicide and a sticker-spreader in your sprayer. Apply in the fall and early spring before infection. If infected, tip cut the affected leaves and apply again. Maneb have been proven effective. Check with your local authorities as to pesticide and fungicide use. Fungal Leaf Spot - Photos by Russ Rodrigue Bacterial Soft Rot In some years this can be a major problem that can almost wipe out a planting if allowed to spread without remedial action.

The pathogen is Erwinia carotovora (yes, it affects carrots) and affects all the bearded irises. It presents as a soft, foul-smelling rhizome rot followed by wilting and dying of the leaf fans. It is prevalent in wet springs with high temperatures. If you observe this and smell it, get busy cleaning it out! Use a spoon and scrape the infected tissue out. The wounds in the rhizomes need to be exposed to the sun. Then powder the wound with a chlorine based cleanser. Instead of the cleanser some people douse the rhizomes in place with Dial antibacterial soap (with triclosan). Fungal Crown Rot This can affect bearded irises, and rarely here Japanese, Siberian and Spuria irises. It presents as a gray or tan cottony mass over leaf bases and adjacent soil and rhizomes. The leaves turn yellow at the tip, rot at the base, and eventually fall over. Many times a secondary infection of bacterial soft rot will also occur. This fungus is most destructive during warm weather with moist soil.

The pathogen is Sclerotium rolfsii, also know as mustard seed fungus, because it also presents as brown, spherical sclerotia, about the size and color of mustard seeds, when inactive. It is controlled by sanitary growing conditions, the cleaning out of infected tissue, exposure of the rhizomes to the sun, and at planting or transplanting time dipping the rhizomes in a fungicide or 10% Clorox solution. Pests Iris Borer This critter is the scourge of the East and Midwest. Garden sanitation is most important to avoiding this borer. Study its life cycle: Macronoctua onusta is a caterpillar, the larvae of a medium-sized, nondescript noctural brownish moth. In autumn the moths lay their eggs on old iris leaves and other nearby debris. The eggs survive the winter and hatch out with warm weather in the spring. The tiny white caterpillars search out fresh iris leaves, which are usually less than a foot tall at this time. Early damage is hard to detect but as they grow they begin to attack the edges of the center foliage making notches and leaving slimy frass.

If you catch them early you can crush them in the foliage with your fingers. Iris borers are proven cannibals with only one surviving in each iris by the time they are half-grown. But they do significant damage as they proceed down the leaf sheaf or bloom stalk to the iris rhizome. The borer will hollow out the rhizome and sometimes migrate to an adjacent rhizome and do the same. They have to be dug out at this point and have grown to between one and two inches, are pinkish in appearance with dark brown heads. Ugly! In late summer they leave the rhizome entering the soil and becoming dark brown pupae. This dormant stage allows the caterpillar to transform into a moth in the autumn, when they emerge, mate and lay their eggs to start the process over. Most pesticides are not effective against the iris borer. Garden sanitation and visual inspection of your plants is most important. Two systemic insecticides with reportedly good effect are Merit and Cygon 2E. Read the labels and apply sparingly with a spreader-sticker in early spring (when irises are about 4-6 inches tall) at least three times every 7-10 days.

Eggs hatch at different times so you may get different batches dependent on the microclimate in your garden. Stay vigilant! There have been no confirmed reports of the iris borer west of the Rocky Mountains. Borer in a rhizome and a borer Pupae and moth Aphids These small green or gray insects are sapsuckers. They appear on the iris leaves in clusters and proceed to suck out leaf sap. They also can spread disease between plants. They are easily controlled by physical removal or crushing with your fingers. Lady bugs like them too. Spraying with an insecticidal soap or liquid dish detergent is effective. Verbena Bud Moth This critter appears to only be a problem for iris hybridizers who have seed pods developing from their iris crosses. The Endothenia hebesana, bud moth attacks the seed in the pods. It has the same life cycle as the iris borer. Sanitation and cleaning up seed stalks and capsules is the only known control. Crickets There are hundreds of species of crickets in the U. S. Crickets feed on just about everything. They will eat seeds, dead insects, leather, paper, old clothes (cotton, wool and silk), and plants.

This includes the rhizome of the iris plant. They will eat holes in the rhizomes which can later be a home for pill bugs and result in soft rot from the rhizome's injury. Adult crickets spend their days in shallow burrows beneath stones, wood or plants. They are most active in late evening and the night when males begin their serenading to attract female mates. A cricket's life begins as one of about 300 eggs a female lays in the soil during late summer and fall. Some species overwinter as nymphs or adults, others as eggs which hatch in the spring. A year-old cricket is a rarity. Crickets can be controlled by a general purpose insecticide. Woodlice (also known as Pill Bugs or Rollie-Pollies) The pill bug is the only crustacean that can spend its entire life on land. Their shells look like armor and they are known for their ability to roll into a ball. The common pill bug Armadillidum vulgare normally feeds on decaying vegetation but will burrow out holes begun by crickets in iris rhizomes.

Called roly-polys in some areas, these little critters are found under stones, logs or any other space where moisture is found. When assuming a defensive posture, they curl up in a ball. They can be controlled by a general purpose insecticide. Moles This small brown burrowing mammal is in the Talpidae family. Its diet primarily consists of earthworms, grubs and other small invertebrates found in the soil. Their saliva contains a toxin that can paralyze earthworms. Because of this, moles are able to store their still living prey for later consumption. The problem they create for plants is the air space from their burrows causing plant stunting and non-bloom. Everyone has their own methods for trying to eliminate moles. The only sure way is to move to Ireland where they don't exist. Voles This small rodent is blackish brown to grayish brown, 5-8 inches long resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head with pointy nose, and smaller ears and eyes.

They live underground in burrows (often using a mole's) but travel aboveground through runways they make by eating everything in their path, be it grass, herbaceous plants, bulbs, tubers and even tree roots or tree bark at the ground level. They can be controlled by toxic baits, such as the anticoagulants brodifacoum and bromadiolone, and by trapping. An alternative is to use mouse traps with a piece of cheese placed right in their run. They seldom veer off these runs. Bearded Irises | Garden Guides Bearded Irises Bearded Irises by Susan Gray Few flowers are as user friendly to the weekend gardener as the bearded iris. Offering carefree blooms in nearly every color of the rainbow, bearded irises are easy to establish and require a minimum of maintenance. Petals that vary in texture from the most plush velvet, to the finest silk, often on one flower, provide variety to suit almost every taste. Unlike most spring bulbs, bearded iris don't require a period of cold to produce blossoms, making them perfect for areas with mild winters. They are also extremely drought tolerant, good for areas with little or no summer rains.

Bearded irises are not actually bulbs, but rhizomes, a kind of thick brown root. Hardy in zones 3-9, the rhizomes need plenty of sun to bloom well and regularly. They do best in well drained soil, but will tolerate less drainage in drier areas. To plant a rhizome, dig a large hole, fill the center with a mound of well broken up soil and set it on top. If planting in the fall when dormant, cut back existing roots to about three inches. Iris planted in the spring should have their roots fanned out around the sides of the mound. The rhizome itself should sit at about ground level. Growers differ as to whether it is best to cover the rhizome completely with a light layer of soil or to leave the tops a bit exposed. For the weekend gardener, soaker hoses make watering irises a breeze, providing deep watering slowly when they dry out. In Southern California I water once every week to ten days. Irises multiply out from the center, which over time, becomes dry and dead. Every three to four years, they need to be dug up, divided into new plants and replanted to provide the most flowers.

The best time for planting in Southern California is in September (or even October, when fall weather is hot). In other parts of the country you may do better to plant right after they bloom in the spring, generally April or May. Cut off dead blossoms and dead bloom stalks when the iris has stopped blossoming, but don't cut back the leaves until they begin to turn brown in the fall. The leaves are needed to produce next year's blooms. When you do cut, leave a fan shape about six inches long. Feed your irises a teaspoon of bone meal every fall and when you replant. You can feed again a month before they usually bloom if you like, but they are quite tolerant of just one feeding. With so many colors to choose from, most people buy their first irises in the spring from growers or garden centers where they can see the plants in bloom. Larger growers often have colored pictures of most varieties in their catalogs. But buying from smaller local growers whose catalogs may lack pictures is not difficult, if you know a little terminology. Irises are described by their parts, each of which can be a different color. The three petals that grow upward on the top of the iris are called Standards.

The three that hang down are referred to as Falls. The smaller often fuzzy or hair like parts in between are the Beard. If an iris is all one color it is called a Self. When I first started growing irises I was enamored of the deep purple to velvet black Selfs. Bearded irises are among the few flowers to come in a true black. In fact, they come in every color except green. One of the first Irises I won a ribbon with in local competition was an old fashioned purple Bi-tone called Lothario Again. Bi-tones as their name suggests are two shades of one color, in this case, violet silk Standards and deep purple velvet Falls. When the Standards and Falls are different colors they are referred to as Blends. The real mystery group is the Plicatas. The petals of Plicatas have light colored centers edged in a darker shade, but this allows room for quite a variety of combinations. The prolific Jesse's Song with mid- purple Standards touched with white in the center and Falls of white with an inch and a half border of dappled purple around ruffled edges is one of my standbys.

Pot Luck is a Plicata whose petals have cream colored centers edged with a narrow stippling of yellow with a wider band of mulberry overlapping it. Often the edges of a Plicata look like some one painted on the color with a stiff dry brush, leaving distinct spots of varying sizes. I moved on from purples, to reds (usually a sort of rust color instead of bright red) and browns and the strangely beautiful blacks. Here I found one of my best bloomers a true brown with silky Standards and slightly darker velvet Falls, called mysteriously, Witch of Endor. It is what is known as a Rebloomer, often producing a second round of blossoms in the fall. Another similarly named favorite is Witch's Wand with black Falls and a purplish black Standard. Some people collect mostly one color, others a rainbow of hues. The oldest irises are often tall and simple. I rescued a bunch of irises from the garden of an older house being torn down a few blocks away from my home. Digging them up, a few steps ahead of the bulldozer, all I remembered was that they were a soft lavender I had often admired in driving by.

When the irises blossomed the following spring, I had two varieties one lavender and one white, both Selfs, with simple old fashion flowers that reach four to five feet in height. Newer varieties may have ruffled or lacy (deeply ruffled) petals and tend to be in the two to three foot range. Soon I had more irises than I had room or sunlight. Each time I dug up irises in the fall, I found myself looking for homes for orphaned rhizomes. Still I was seduced into trying out a few more by names like Conjuration, New Moon, Superstition or Strange Magic. Some names speak of other places like: Fresno Frolic, Mt. Cook A'Dawning, Miss Atlanta or Barbary Coast. There are irises named for music like Jazz Jubilee or Mountain Melody, or astronomy like Pulsar and Quasar, or even for drinks like Margarita Time and Tequila Sunrise. Whatever your interests, you can find irises whose names reflect them. Easy to grow, irises ask little in the way of gardening time and offer a seemingly endless range of colors and combinations. The bearded iris has much to reward today's busy gardeners.

Louisiana Iris Growing Tips - Culture and Propagation Organization ï¿½|ï¿½ Katrina |ï¿½ Contact ï¿½| About Zydeco ï¿½| Home ï¿½| Site Map Louisiana Iris Growing Tips and Culture Additional Information Culture Resources: Growing Information For Various Regions and Conditions The general garden culture of Louisiana irises is fairly simple. While these irises do have a few preferences, they are not difficult to satisfy. Louisiana irises are adaptable to most parts of the country. Although the preponderance of the irises found in the wild occur along the Gulf Coast, two of the five species are indigenous as far north as Illinois, Indiana, Ohio and Kentucky. One, I. brevicaulis, is found in Ontario. Experience with Louisianas in colder climates has been good. There is a very successful public planting of Louisiana irises in Highland Park in Rochester, NY, for example, a spot some might have thought too cold. Some cultural practices are constant regardless of latitude, and others need to be modified.

More has been written about recommended growing practices in the South, and Zydeco Louisiana Iris Garden is located in New Orleans, which is challenged by only about an inch of snow every ten years. The experience underlying the following observations and suggestions is decidedly southern, but information on other climate conditions will be noted when known. The Culture Resources link will take you to growing tips specific to other regions and states and to varying growing conditions. Propagation techniques for Louisiana irises are discussed on a different page as well. General Location The low and wetland origins of the native species should not imply that Louisiana irises require aquatic culture. They do love water and thrive in ponds and boggy settings, but Louisianas also grow and bloom exceedingly well in typical garden beds. These irises should not be allowed to dry out during periods of drought, however. They will stay green and grow through hot weather only with ample moisture. Louisiana irises should be grown in half to full sun. Less than a half day of sun will diminish bloom. It is highly advisable to avoid close competition with large trees or plants with extensive root systems that would use most of the soil moisture.

In hot climates, unless the irises are in ample water, full sun may stress the plants at certain times of the year. Louisiana irises can be mixed with most smaller ornamental plants. They also can be grown in beds consisting entirely of irises, although iris-only beds may not be as attractive in late summer as the foliage begins to die back in preparation for the new growth cycle that begins in the fall. Any yellowed foliage can and should be removed to improve appearance and encourage new growth. Soil Conditions and Preparation An acid soil is often recommended for Louisiana irises, but this is not necessary. Soils in much of the Gulf Coast are acid, but some areas, such as parts of New Orleans and the Mississippi River flood plain, may be neutral or a bit alkaline. Since Louisiana irises were found in the wild in these areas, they had to be happy with the natural conditions. However, Louisiana irises grown in very alkaline soils, such as in some Western states, will exhibit yellow leaves and stunted growth. There has been no systematic test of the limits of tolerance in an acid or alkaline direction, but experience in the 6.5 to just over 7.2 range has produced excellent results.

Irises need a soil high in fertility and organic matter. Finely ground pine bark, composted oak and other leaves or rotted manure, for example, are excellent additions that should be worked into the soil when beds are made. If the soil has a clay texture, adding some sand may be helpful. Although these irises in the wild may be found in clayey muck, a loose and friable soil is helpful in promoting growth and bloom in garden conditions, provided that the irises do not dry out. If the irises are grown in water instead of a garden bed, there are other factors to consider. With any container placed in a pond, a soil too light may tend to float away. Store-bought soils and amendments, unless designed for aquatic culture, may not be well adapted for pots immersed in water, and a heavier soil is advised. In water culture where the appearance of the water is not an issue, such as in natural ponds or large containers not intended to fit into a naturalistic pond setting, a wide variety of soil types seem to work well, from nearly soil-less mixes to typical garden soil. If possible, prepare iris beds a few weeks before planting, but don't fret if you have to plant immediately.

The traditional recommendation is to add the organic material (2-3 inches) and a generous amount of commercial fertilizer (for example, 8-10 lbs. per 100 sq. feet of 8-8-8) to the bed, and work in. An azalea/camellia fertilizer is a good choice if there is a need to adjust for an excessively alkaline soil. Organic fertilizers are also effective, although the amounts equivalent to a balanced chemical fertilizer are difficult to estimate, and not much guidance is available specifically applicable to Louisiana irises. If you want to use organic fertilizers, however, a Georgia Cooperative Extension publication may be useful (no longer online, but the link is to a pdf version). Planting and Dividing Unlike most plants, which go dormant or grow little in the winter, the growth cycle of Louisiana irises in their native range actually begins in the fall, continues through winter and culminates in a burst of rapid growth and bloom in the spring. When the weather gets hot, growth may slow or even stop, especially if moisture and soil fertility are not optimal. In the north, the winter growth may not occur, and snow and cold will interrupt growth cycle.

Whereas bloom along the Gulf Coast may begin in mid-March, it may be delayed until June in attitudes such as the Upper Midwest. Timing. Consistent with irises' growth cycle, the best time to plant and divide Louisiana irises along the Gulf Coast is mid-to-late August, September, October, not long after the period of new growth has begun. Irises planted later than November are not likely to become well enough established to reach normal size and bloom in the spring.In cold climates, fall planting is also recommended, but early enough to let them establish before the coldest weather. August and September are the preferred months.Transplanting immediately after bloom is not recommended. The hot weather following closely upon the bloom season will stress the plants, and little growth or even an early dormant period may result. The longer into the season foliage growth can be continued, the better the chances of good bloom the next year, because the plants have a greater opportunity to grow larger rhizomes to support bloom. If it is necessary to transplant after bloom, be sure to supply extra water. Alternatively, hold the irises over in water, or in pots set in shallow water and partial shade, until new growth has resumed or until the fall planting season.

Growers in such warm climates in South Florida report that Louisianas can be divided at any time of the year. Placement. Irises should be planted with about ½ to 3/4 inch of soil covering the rhizome and, ideally, 1-2 inches of mulch over the soil. Planted about 12 inches apart, Louisiana irises can be left in place 3-4 years and will form clumps. Every several years, it is helpful to dig and divide the irises, thinning them out and replenishing the soil with organic matter as if preparing new beds. Remember that the rhizomes grow longer as new leaves emerge, and varieties planted too close together will become mixed and difficult to identify. The rate of "traveling" varies with the particular variety, since the typical size of the rhizome varies. Two or more offsets generally form each year on either side of the rhizome, and their growth extends roughly perpendicular to the original rhizome, which results in the tendency for a clump to develop. Each rhizome blooms only once, then the offsets bloom in subsequent years. Keeping this grown pattern in mind is helpful in deciding where to plant Louisiana irises.

(Plants produced as offsets will be identical in every respect to the parent rhizome; plants grown from seed will vary, perhaps markedly, depending upon the identity of the particular parents). Watering Watering is often necessary to achieve a sufficient growing season for good bloom. The beds should not be allowed to dry out. September and October are relatively dry along the Gulf Coast and it is important to give the iris beds a thorough soaking at least once weekly during such dry periods. In summer, a dry spell without good watering will cause growth to halt or even cause the plant to go dormant. Fertilizing In truth, fertilizing practices vary a good bit among Louisiana iris growers. The traditional advice has been: For new or replanted beds (to which fertilizer and organic material have been added at planting time), a light dressing of a complete fertilizer (2-4 lbs. per 100 square feet) is sufficient about two months prior to bloom (late January in Louisiana). Beds which have not been replanted in late summer are generally given two applications, a fairly heavy one at the start of the growing season, and then the light dressing just before bloom.

Complete fertilizers such as 8-8-8 are said to be preferable to high nitrogen fertilizers. High nitrogen can cause the plants to produce leafy growth while suppressing flowering; it also is thought to render the plants more susceptible to some diseases. An acid-forming azalea/camellia fertilizer should be used if the soil tends to be too alkaline, as in parts of the West. Many serious growers of Louisiana irises deviate from this recommendation in several respects. Some recommend a third feeding after bloom. Some favor liquid fertilizers, and some select fertilizers with additional nitrogen. Timed-release products are occasionally recommended, especially in water culture. We do know that Louisiana irises are heavy feeders, and there is little doubt that the average gardener fertilizes them a good bit less than optimal. Failure of foliage to remain pretty and green in the hot months after bloom probably is due to insufficient water and less than optimal nutrition. Cases of problems from over-fertilizing are rare, but the complaint that "my irises did not bloom" is often associated with failure to fertilize. Mulching Mulching is an important part of good culture.

Mulches serve many purposes, such as maintaining soil moisture, keeping weeds under control, increasing organic matter in the soil, and protecting against sun scald (see below). About 2-3 inches of rotted or even fresh leaves, pine straw or pine bark are excellent mulches. Materials available locally, such as bagasse (sugar cane fiber), should be considered. Diseases and Pests In their native range, Louisiana irises are not prone to many diseases and insect pests. Most growers are able to easily endure any small nuisances without having to resort to insecticides or other treatments. In other sections of the country, some additional problems are reported, and the grower is advised to seek information on local conditions. Some the links on the Culture Resources page may be useful. Rust appears as red to dark-brown powdery spots, often surrounded by a yellow margin, on leaves and stems. Leaves may become severely discolored and die back. The rust does not appear to damage the plants severely, but it does make the beds look bad. Avoiding too much fertilizer, especially high nitrogen, is said to potentially limit the spread of rust. Some growers feel that cow manure, specifically, may promote rust.

The best way to avoid rust is to remove and discard withered leaves. Rust is a soil borne fungus, and if infected leaves are not permitted to decay in the garden, the life cycle of the fungus is disrupted. Stands of Iris fulva in the wild are often infested with rust. This is not due to gardeners who applied too much nitrogen, but rather by their unavailability to clean up and dispose of the infected foliage. If an infestation of rust does begin, it is important to remove affected foliage to the extent possible (put it in the garbage can, not the compost pile). Some growers recommend spraying plants in the area of the rust with such products as Ortho's Garden Disease Control or Fertiloam Systemic Fungicide, but there is no substitute for removing the infected leaves from the garden. If the bad foliage remains, the rust is likely to return the next year; if it is removed, there may not be another outbreak for some years. Leaf Miner is indicated by white steaks along the leaves, particularly near the base, in hot weather. It is caused by the larva of a type of fly. The outermost leaves may collapse, and, if they become unsightly, can simply be removed.

Leaf miners rarely cause enough trouble to warrant treatment with an insecticide. Iris borer may be a problem now and then in the Gulf South, but it is more serious to the north and in areas where bearded irises are grown. The worm enters the rhizome and may hollow it out and effectively kill it or destroy its ability to produce a bloom stalk. The first sign of a borer may be a center leaf in a fan that turns yellow and dies. This occurs because the borer, first deposited on the leaves, has worked its way down to the rhizome and devoured the growing tip. If one watches for center leaf damage, the borer can sometimes be found and destroyed before the rhizome is seriously injured. Some chewed or damaged foliage may be evident early, before the borer has reached the rhizome. Sometimes it is possible to gently spread the leaves of a fan and kill the critter before it does real damage. A rhizome damaged by a borer will often produce offsets unaffected by the problem, so there is no need to discard the entire plant. Snails and slugs may climb up the scapes and disfigure a bloom, particularly under conditions of high humidity and rainfall.

Some growers use a commercial snail bait and others set out saucers of beer. Snails are not a problem of sufficient severity that most do anything about it at all. Those who grow irises for entry in shows may be the exception. Sun scald is not a disease, but a condition resulting from the sun scorching an exposed rhizomes in midsummer, causing them to become mushy and to deteriorate. Unlike bearded irises, Louisiana iris rhizomes do not naturally grow along the top of the soil, but usually just below the soil level. Sometimes, especially late in a season, the top of the rhizome may be come exposed. Adding soil or a mulch solves this problem. Cutworms are sometimes a problem. Cutworms are chewing insects that will sever leaves and disrupt growth. One recommendation is a fertilizer fortified with an insecticide, such as that sold for control of lawn chinch bugs. Moles and voles are serious problems in some areas. Some growers have reported growing Louisianas in containers sunk in the ground to prevent the rhizomes from being eaten. If drainage in the container is obstructed, this offers the added advantage of promoting constant moisture.

This tactic obviously is more work than just digging a hole in a garden bed and planting an iris, and if the container is not sufficiently wide the irises will soon escape as the rhizomes grow longer.

Question: The Iris has a thick-stemmed root instead of a bulb. By what name is this 'root' known?
Answer: RHIZOME