Capturing 

and Using the 

Rains of the 

Great Plains

Rain Gardens

Indiangrass

Blanketflower

Blue Fescue

Prairie Coneflower

Bleeding Heart

North Dakota

Helping People Help the Land
Figure 1. A 200-square foot rain garden blooms just 2 months after construction and planting.

What is a Rain Garden

A rain garden is a colorful, perennial planting 

designed to capture and use rain water that may 

otherwise run off. (Figure 1) It is a garden in a 

shallow depression. It can be large or small. A rain 

garden is not a wetland and should not hold water 

for more than a few hours, or a day at most. It is not 

a breeding ground for mosquitoes.

Figure 2. A new rain garden captures roof and yard 

runoff from a 1⁄2 inch, 15-minute prairie thunderstorm in 

July. Note the drought stressed yard outside the rain 

garden.

Why Plant a Rain Garden

A Rain Garden 

♦ Captures and filters runoff

Limited rains of the Great Plains fall hard and 

fast. Runoff from roofs, lawns, and drives may 

overload storm sewers and pollute streams. 

(Figure 2)

♦ Reduces the need for supplemental water

Water is often limited in the Great Plains. 

Maintaining a green and colorful yard with rural 

or municipal water can be expensive.

♦ Grows healthy plants using good water

Rain is high quality water, good for plants; while 

well water may be poor for plant health.

♦ Provides changing colors and textures

A mix of plants changes color, structure, shape, 

and form throughout the season. (Figure 5)

♦ Provides habitat

Forbs and grasses in a rain garden are attractive 

to butterflies, bees, birds, and other wildlife.

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Figure 3. Plan View of Rain Garden

Rain Gardens 

from

“Thought to Bloom”

√ Read a good “how to” 

manual (See references)

√ Check local ordinances 

√ Check for utilities

√ Locate potential site

√ Determine size

√ Draw a plan 

√ Outline the area on the 

ground

√ Build the rain garden

√ Plant the rain garden

√ Apply shredded wood 

mulch 2-3” deep before or 

after planting

√ Water and weed as needed

√ Enjoy the ever changing 

array of colors and textures 

from spring to fall

Figure 4. Cross-section of Rain Garden

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Where to Establish a Rain Garden

Locate a rain garden to intercept runoff from roofs, 

yards, drives, or streets. (Figure 2) It should not be 

built within 10 feet of foundation walls or on poorly 

drained sites. A rain garden should not be built over 

buried utilities or where mature plants could obstruct 

overhead utilities or drivers’ vision. Do not construct 

a rain garden where prohibited by local ordinances or 

where subject to disturbance.

How to Build a Rain Garden

Most rain gardens can be constructed with equipment 

available to homeowners such as shovels, rakes, and 

rototillers. A small rain garden of simple design can 

be built in a day. 

• Do your homework first. Many design manuals are 

available, online and at public offices. Several are 

listed in the reference section of this publication.

• Locate a proper site.

• Calculate square footage draining to the rain 

garden (from roof, yard, drive, etc.).

• Mark outline of rain garden. Rain garden area 

should equal about 10% of the drainage area. 

Irregular margins are often more attractive. 

(Figure 3)

• Evaluate soil compaction, texture, and infiltration.

• Dig a 4-8 inch deep basin with a flat bottom. 

Excavated material can be placed on the downhill 

side or moved offsite. (Figure 4) Avoid compaction 

during construction.

• Loosen 6-12 inches of the natural soil below the 

bottom of the rain garden.

• Large designs or sites with high clay content soils 

may require over-digging the basin 1-2 feet deep, 

backfilling with a well blended mix of 70% sand 

and 30% organic matter (yard compost, purchased 

peat moss, etc.), and shaping the top of this 

material into a 4-8 inch deep basin.

• Slope and pack any created berms, leaving a 

gentle slope that will be easy to maintain.

• Smooth, seed berm, and plant the rain garden.

• Apply shredded wood mulch as desired to conserve water and control weeds. Shredded mulch 

stays in place better than wood chips.

• Water and weed to establish plants.

Checking 

depth with a 

carpenter’s 

level

How to Plant a Rain Garden

Use potted or bare root plants rather than seeds. 

Plant from April to September. Place the more 

water tolerant species near the bottom, and drought 

tolerant near the edges. Plant spacing will vary 

depending upon species and desired appearance. 

Generally, 15-18 inches between plants is adequate. 

Consider mature size when spacing plants.

Figure 5. For much of the summer in the Great Plains,

 a rain garden might be the only “green” area 

in a non-irrigated yard.

What to Plant in a Rain Garden

Rain gardens can be planted to native or nonnative species of flowers, grasses, shrubs, and 

trees. Do not plant species considered invasive. 

Consider the growth habit and mature size of the 

species. Some native species are deep rooting and 

encourage infiltration of runoff water. Native species 

are adapted to local conditions and may be more 

tolerant of diseases and drought, compared to some 

non-native species. A diversity of plant species will 

provide an array of color and texture, and attract a 

variety of insects and wildlife. Disease and insects 

may destroy an entire rain garden if planted to a 

single species. Plants requiring constant moisture 

should not be planted in a rain garden. Use locally 

adapted species and varieties.

How to Maintain a Rain Garden

Very little additional water or weeding is needed 

once a rain garden is established. Supplemental 

water is usually needed only to establish plants and 

during drought. Apply and renew mulch as needed to 

control weeds and conserve water. Leave vegetation 

standing over winter for snow catch, textural diversity, 

and visual interest. In early spring, remove previous 

year’s growth by mowing or clipping before new 

growth initiates. 4
For more information, contact:

• USDA Natural Resources Conservation Service

• Soil and Water Conservation Districts 

• Land Grant Universities and Cooperative Extension Service 

• Local Greenhouses and Nurseries

References and Additional Reading*

“Living Landscapes in North Dakota: A GUIDE TO 

NATIVE PLANTSCAPING” 

Available at North Dakota NRCS offices. Booklet contains 

detailed information on site evaluation, planning, and 

establishment of native plants. Adapted forbs, grasses, trees, 

and shrubs are listed and described.

“Rain Gardens - A how-to manual for homeowners”

http://www.dnr.wisconsin.gov/org/water/wm/dsfm/shore/documents/rgmanual.pdf

This is an easy to follow manual that shows homeowners how 

to plan, install, and maintain a rain garden.

“Rain Gardens, Rice Creek Watershed District”

http://ricecreek.org/bluethumb/raingardens

This Minnesota web site has information on creating and 

planting rain gardens and more. A very effective plant selector 

tool is part of this site.

Maplewood, Minnesota “Rain Water Gardens”

http://tinyurl.com/2yvxxa

The rain garden program at Maplewood is explained. Pictures 

and designs of many different garden types are included. 

Links within the document give complete details from design 

through maintenance.

*Note: When using these references, select only plant 

species adapted to your location. 

Buried pipes and cables can kill

Check with a utility location service or electric, gas, phone, 

or cable suppliers to locate buried utilities that may be affected by construction. Some buried utilities are quite shallow 

and easily severed by a hand shovel, causing death or injury.

CHECK BEFORE DIGGING!

By: Craig Stange, Forester, Ecological Sciences Staff

Nancy Jensen, Agronomist, Plant Materials Center

USDA-NRCS, Bismarck, North Dakota

April 2007

All programs and services are offered on a nondiscriminatory basis.

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