prune false cypress

Question: About 10 years ago, we planted 3 Golden Thread False Cypress as foundation plants near our house.  The nursery tag stated that the height at 10 years would be 2-3 ft.  Well, they must like the location as they have grown much higher and wider.  Even with substantial trimming each year, they grow taller and wider than I would like. This year, they are about 5' high and 6' wide.  They seem to grow more than I can trim and still retain their graceful shape.  My Question:  Will the plants regenerate if I prune the bushes down to bare wood? I would prefer to keep the false cypress but they are getting out of hand. Thank you!

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 07, 2024, 10:32 AM EDT
response: Plant mature size information on tags can unfortunately be misleading, not necessarily because the nursery grower was being deceptive, but because lots of factors influence growth rate, and plants also never truly stop growing as they age (though they can slow down). Without the botanical and cultivar name of the plants you're growing, it's hard to say what their typical size winds-up being, but if they are 'Gold Mop' (a very widely-sold and widely-planted variety), then can easily mature in the 10-foot range once they are a couple decades old or so. (They're also usually much yellower than this picture implies...are they growing in full sun or does the exposure only receive morning or evening sun? More shade turns such yellow cultivars greener, and might also make them stay less compact.)  Unfortunately no, you can't prune them down to size or drastically cut them back to force regrowth. With very few exceptions, conifers (needled evergreens like cypress, pine, juniper, and spruce) cannot produce new growth on old wood. Branch wood that is several years old no longer has dormant growth buds that would be stimulated into growth by pruning, compared to broadleaf evergreens (holly, boxwood, etc.) that do. Therefore, when any style of pruning makes cuts back into wood that's more than a few years old, that cut is permanent and no regrowth fills back in.  If you want to keep the plants and have a space for them to grow larger without blocking a view or running into obstacles, you can transplant them (now is probably fine, or very early autumn or next spring) out of this space. We can offer ideas for replacements if you'd like, though we'd need information about the site conditions in order to narrow-down some options. (How much direct summer sun it receives, how well-drained, damp, or dry the soil is, if deer browse in the area, and what mature size (without relying on pruning) the space can accommodate.)  Miri

responder: The Question Asker Replied June 07, 2024, 11:57 AM EDT
response: Thank you so much for your reply! Unfortunately, we don't have an appropriate place to transplant but we would really appreciate your recommendations as to replacement plants.  The site is NNW in front of a low roofed breezeway, well-drained soil, gets morning and afternoon sun and deer grazing is a problem.  Mature size (without relying on pruning) of up to 3.5'. We'd be open evergreen and/or deciduous plants. Thank you!

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 07, 2024, 12:56 PM EDT
response: Thank you for the site description. Below are some ideas, but it's just a starter list and is far from exhaustive (though the deer browsing pressure will keep the list overall fairly limited). Since you are open to both evergreen and deciduous plants, you have lots of choices, especially since a lot of plants these days have cultivars on the market that are dwarf or compact compared to the regular form. The list below is in no order of importance; some species listed come in many cultivar forms, so they can vary in mature height and traits like leaf color. Botanical names are in parentheses, since common names sometimes vary. We'll assume the sun level in summer that you describe is at least 4-6 hours of direct sun ("full sun" is generally 6+ hours of unobstructed sun in summer), based on the note that it faces NNW, which is usually not a full sun exposure.  Depending on the space available width-wise, we'd recommend using a mix of species (or at least more than one), so they will have an overall higher resilience to a potential pest or disease outbreak (or weather damage) since plant tolerances and stressors can vary from one species to another. A mixed planting also allows for more seasonal aesthetic interest or the use of contrasting leaf textures or colors.  EvergreenBoxwood (Buxus, several species and numerous cultivars) While this group has their potential problems (to be fair, everything can get infected/infested by something), look for cultivars that tout good resistance to disease (like Boxwood Blight) and insects (Boxwood Leafminer). Several have been introduced in recent years that are resistant to both. Some cultivars even have colorful foliage (white-edged or yellow-edged), though we don't know the resistance ranking of those in particular. Boxwoods trim easily, but should ideally be left to their own natural shape since heavy pruning increases their vulnerability to disease.Chinese Holly (Ilex cornuta) The spinier-leaved cultivars are unpalatable to deer, though surprisingly, most other hollies can be eaten. A few cultivars stay small enough, but also can be pruned. Many (if they are female) can produce berries without needing pollination.Inkberry Holly (Ilex glabra) Included if you prefer using a locally-native evergreen, though they grow and look their best in full sun. Spineless leaves must taste bad to deer, since they usually leave them alone. Look for a truly-dwarf cultivar like 'Gem Box' or 'Stongbox' since popularly-grown varieties like 'Shamrock' are not as compact over time a their plant tags might imply, and pruning Inkberry down to size is not something the plants handle well (from an aesthetic standpoint). Be aware that this holly species is naturally not as dense-growing as the widely-grown non-natives like Japanese Holly or Chinese Holly, especially if grown in less than full sun.Japanese Plum Yew (Cephalotaxus harringtonia) Unlike their Yew (Taxus) cousins, these are unappealing to deer, though just about anything could get exploratory nibbles. Light trimming is okay to restrain size, but there are a few compact-growing cultivars that should fit; they will mature wider than tall.Leucothoe (Leucothoe axillaris or L. fontanesiana) Branches naturally arch into a fountain-like shape (plants grow wider than tall), and some varieties have leaves marbled with cream, edged in white, or which turn burgundy-red in winter. White blooms decorate the branch tips around mid-spring. Native to parts of the eastern U.S., though technically not in Maryland.American Holly (Ilex opaca) Native. While much too tall in its wild form, there are a couple dwarf cultivars that stay small enough to use here, though they will (very slowly) grow wider than tall. 'Maryland Dwarf', appropriately enough, is one that is becoming a bit easier to find at area nurseries, though overall dwarf cultivars of this species are somewhat rare. Since growth is so slow, it will take several years to fill-in from the purchased size, and they can be proportionately more expensive than some other shrubs their size, especially among hollies. American Holly is very flexible about how much sun it gets, and is also tolerant of damp sites as long as they aren't too soggy.Eastern Redcedar (Juniperus virginiana) Native. Like the above, most forms will be much too big to use in that spot. However, there are some dwarf cultivars, like 'Gray Owl' and 'Gray Guardian' (which also happen to be blue-gray in color). Junipers as a group prefer full sun, but if they receive enough light, they can handle a bit less than full sun. These too will grow wider than tall (to the point of being around 4 to 6 feet wide each, depending on cultivar). Light trimming is possible, but otherwise they look their best unpruned. DeciduousSummersweet (Clethra alnifolia) Native. Dwarf cultivars stay small enough to fit in your space, though they can slowly spread (sucker) into a clump wider than tall. Flowers appear in summer (white, as the few pink forms are taller-growing) and are very sweetly fragrant, attracting lots of pollinators. Fall color is yellow. They prefer soil that skews more damp than dry, so if an overhang keeps them from getting some rain, monitoring for watering during dry spells would be beneficial.Virginia Sweetspire (Itea virginica) Native. Cultivar height differences aren't drastic, but the one most well-suited to your needs might be 'Little Henry' since it stays shorter. Flowers are lightly scented and appear around late spring. Fall color can be anywhere from burgundy-red, to red-orange, to a mix of red, orange, and yellow. Sometimes a handful fall-colored leaves remain on the stems for the winter.Bluebeard (Caryopteris x clandonensis) Flowers best in full sun, but as long as it gets at least about 5 hours worth, it should still bloom well. Gray-tinged foliage is somewhat felted in texture and the lavender-blue blooms appear late, anywhere between late July and early September or so. Poplar with pollinators. Several cultivars exist, but there are minimal differences between them, and all (or most) will fit in that space with little to no pruning. Prefers to be a bit on the dry side and tolerates drought well, so avoid growing near any roof downspout outlets that might empty close by.Slender Deutzia (Deutzia gracilis) Although potentially a little too short, this wide-spreading shrub will tolerate full sun and part sun, but will flower best with full sun. White or pink-and-white blooms appear in spring, and foliage might turn burgundy-maroon or reddish in autumn (depends on the cultivar). Some cultivars also have white-edged or golden-leaved forms. If too short by itself, it might be useful in front of taller plants.Glossy Abelia (Abelia x grandiflora, might be under the other name Linnaea x grandiflora) Placed here because, while it sometimes is more evergreen, this trait can vary quite a bit based on weather; it probably falls somewhere in between, shedding some leaves but keeping a few. Many cultivars exist, most within your desired height range. Many have colorful foliage, and all produce white (rarely light pink) flowers, which appear in summer and can rebloom until early fall. Easy to trim if needed, but generally the only pruning done is to remove the occasional errant branch that grows lankily above the rest.American Beautyberry (Callicarpa americana) Native, though not locally; all other Callicarpa sold are non-native, and a few may spread from seed; this species is sometimes hard to find. Tolerant of sun or semi-shade, its blooms are not super showy but appear as pale pinkish-lavender clusters in summer. The main show is the neon purple berries that ripen in autumn, though they won't necessarily last through the winter. Fall foliage color isn't super showy, but tends to be yellow. If a harsh winter or cold snap kills some branch tips, the shrub should regrow well and look normal by summer.Redosier Dogwood (Cornus sericea/stolonifera) Native-ish (rare in MD), though lots of other "redtwig" dogwood species related to this one that are common at nurseries are non-native. Flowers are showy but don't look like typical tree dogwood blooms; they are ivory-white and appear late spring or early summer. Berries are white (on other species of similar-looking shrubby dogwoods, they can be blue-black). Like their tree cousins, they are known for reliably showy fall color in the red range. Plants might sucker a little if thriving, but are easy to control with pruning. Stem color blushes a vibrant red (or orange or yellow, depending on cultivar) during winter, dulling in summer. It can help the plant maintain a fresh, colorful look to prune off the oldest, thickest stems every few years to force new growth to replace it.  Miri

responder: The Question Asker Replied June 07, 2024, 2:29 PM EDT
response: Thank you, again! Those are great ideas. We have a "Little Henry" Virginia Sweetspire in our yard and are really enjoying it. I think that will be one of the plants we will plant to replace the false cypress.  We also planted 3 Inkberry Hollies in our yard. One of them is getting pretty leggy. Will trimming it below the green leaves help it to fill out, or, once it loses the bottom leaves, are they gone forever?? Also, if we transplant the Inkberry to a sunnier location, will the sunnier area encourage it to fill out at the bottom? Thank you!

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 07, 2024, 2:56 PM EDT
response: You're welcome.  Pruning Inkberry Holly back doesn't often result in good regrowth, though hollies in general do tend to respond well to heavy pruning. We have limited experience with trying that method on established Inkberry, but anecdotally, when we've seen hedges maintained at a height much lower than the plant would otherwise grow, they do not look good and do not fill back in much. Once they lose their lower and/or interior leaves, they tend to stay bare there, but they can be underplanted with lower-growing fill-in plants like (if semi-shady) ferns or sedges, or a variety of other perennials (if sunnier).  While sunnier locations do support the retention of more leaves with Inkberry, we don't think moving an established shrub into more sun will do much for leaf density (in terms of putting out more interior or lower growth), but you can always try, since it should at least help the plant retain more of its current leaves going forward. It is normal for all evergreens to shed a few of their oldest leaves each year, regardless of growing conditions and overall health, but this turnover can be minimized by giving the plant in question the ideal amount of sunlight (in this case, full sun, or close to it). This is for aesthetics, of course, since Inkberry in the wild handles semi-shade just fine, though will be more open and leggy from a gardening perspective.  Miri

responder: The Question Asker Replied June 10, 2024, 8:19 AM EDT
response: You have been so very helpful! Thank you very, very much for all of your explanations. We're going to remove the false cypresses, plant some of your above suggestions in their place and move the inkberry holly to a sunnier location. Thanks again and have a great week!

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 10, 2024, 9:24 AM EDT
response: You're welcome!