29 Best Plants for Your Rain Garden
Stop waterway pollution, prevent flooding, and cover mucky low-lying areas with rain garden plants that are as functional as they are beautiful. Former organic farmer Logan Hailey digs into the best species for wet, low-lying areas.
It’s hard to find plants that can handle soggy soils without succumbing to root rot, yet many areas of our yards and gardens temporarily turn into puddles when it rains. You’re in the right place if you don’t know what to plant in extra-moist areas.
A rain garden is a low-lying area where native flowers, shrubs, grasses, and perennial herbs are planted to absorb rainwater runoff. Rain gardens allow runoff from roofs, driveways, and lawns to soak into the soil, preventing nutrient leaching and chemical pollution of waterways.
Each time it rains, water flows off your roof, down your gutters, across your driveway, and over your lawn. Moving water picks up pollutants along the way, including chemicals, fertilizer, oil, bacteria, and sediments.
If this unfiltered water flows into the street and down your storm drain, it ends up in nearby streams and ponds. As this process repeats during every rain event, waterways rapidly become polluted, causing widespread ecological damage.
Think of a rain garden as a natural filtration system. The right community of plants in a strategic location can capture runoff rainwater before it drifts into the street and ecosystem. Rain gardens filter the water through vegetation roots and soil microorganisms to remove pollutants, prevent flooding, and recharge the groundwater.
But not every species is up for this honorable task. Let’s dig into the 29 best plants for a rain garden and how you can plan a self-maintaining system of water purification right in your yard.
What is a Rain Garden?
A rain garden is a depressed, low-lying area specifically planted with perennial plants to absorb and filter rainwater runoff. A combination of native flowers, herbs, shrubs, and grasses can filter pollutants, prevent flooding, and provide resources for local wildlife. Rain gardens are designed to improve drainage and infiltration of water into the soil near a roof, driveway, or street so that contaminated runoff doesn’t enter local waterways.
Properties of Rain Garden Plants
The best plants for rain gardens share a few key attributes that allow them to thrive in conditions with constantly varying moisture.
Response to Moisture:
- Resistance to Rot: Plants susceptible to root rot should not be grown in a rain garden. These species need to be durable and tolerant of high soil moisture levels. However, they do not need to be wetland plants, as a rain garden should not be oversaturated all the time.
- Deep and Wide Root Systems: The deeper the roots, the better plants can stabilize the soil to prevent erosion and ensure proper water infiltration. Taproot plants excel at breaking up compaction layers, while fibrous root systems help capture sediment and create microchannels for water to flow through. Ideally, you have a variation of different root types to create a stronger soil structure.
- Moisture Adaptability: Rain gardens aren’t always wet, so these plants must be willing to endure drastic fluctuations in moisture throughout the season. Heavy rainfalls and long dry spells may challenge fragile cultivated ornamentals, but hardy native species tend to hold up to the challenge.
- Permeable Groundcover: It’s vital that no soil surface is left bare. Otherwise, it will get eroded and cease to function in the rain garden. Ground cover plants protect the topsoil while providing a permeable airspace for rain to infiltrate.
- Pollutant Tolerance and Filtration: Stormwater runoff picks up many pollutants as it flows from suburban and urban areas into the garden. Some plants are more sensitive to soil pollutants, while others can help remediate and remove contaminants. Choose species that can withstand pollutants and aid in soil remediation.
- Low Maintenance: A rain garden should not need regular maintenance like a vegetable garden. These plants may need a once-annual pruning or some help to get established but should otherwise fend for themselves. Native species tend to be the lowest maintenance because they’re adapted to your area’s soil and climate patterns.
- Ecological Support: Rain gardens dual-function as pollinator and wildlife habitat. A biodiverse combination of flowers, herbs, and grasses helps to support a range of local species, from birds to bees to butterflies to beneficial beetles. If located near your veggie or fruit garden, they may even aid in biological pest control.
- Visually Appealing: Nobody wants an eye sore in their yard, no matter how many ecological benefits it may provide. Interestingly, the most visually appealing rain gardens also tend to be the most functional because the diverse range of plants thrive while they do their job.
29 Best Rain Garden Plant Species
Rose Mallow (Hibiscus moscheutos)
Also known as swamp hibiscus, rose mallow blooms large, showy flowers up to 8” across. This dense perennial shrub is native to the southern and eastern U.S.
It tolerates very moist to wet soils rich in organic matter and moderately acidic. Mulch is useful for rose mallow when growing in areas with long, dry summers.
Switchgrass (Panicum virgatum)
This perennial prairie grass is one of the main species of native North American tallgrass prairies. Its natural range spans from southern Canada to Mexico through almost all of the United States east of the Rocky Mountains. This grass naturally grows in a range of conditions, from dry prairies to pastures to brackish marshes, making it perfect for a rain garden setting.
Cardinal Flower (Lobelia cardinalis)
This attractive perennial wildflower blooms big red flowers in terminal spikes. Wild Lobelia is native to most of the United States, growing wild in ditches, ravines, streambanks, and landscape depressions.
The location of cardinal flower in the wild is a blatant giveaway to its adaptability in a rain garden. It requires continuous moisture and benefits from winter mulch protection in colder climates.
Buttonbush (Cephalanthus occidentalis)
The handsome spike-ball flowers of buttonbush are as attractive to bees as they are to humans. It’s almost hard to believe that something so unique and beautiful is a swampy wildflower. Buttonbush is native to the eastern U.S. and particularly thrives in swamps, streambanks, and prairie swales.
It tolerates poor drainage and standing water and grows as a spreading, multi-branched shrub. The pincushion flowers are great for native bees, and the button-like fruit balls yield seeds beloved by ducks and other waterbirds.
Swamp Milkweed (Asclepias incarnata)
This tall, showy perennial produces gorgeous rose-to-purple flowers with very little effort. As a major host plant for monarch butterflies, swamp milkweed earns its space in rain and butterfly gardens.
Named for the Greek god of medicine, Asklepios, milkweed is native to nearly every state in the U.S. (excluding California, Arizona, Oregon, Washington, and Mississippi). It grows prolifically in sunny swamps, marshes, bogs, ditches, and streambanks, thriving in waterlogged to slightly moist soil. As long as it never fully dries out, swamp milkweed thrives in a rain garden.
Winterberry (Ilex verticillata)
Add some winter interest to your native rain garden with this red-berried small tree. Though it is a member of the holly family, winterberry does not have the sharp-toothed leaves of other hollies.
It naturally grows near lakes, ponds, and riverbanks as a short tree with attractive green foliage. Native to the eastern U.S., it tolerates a range of soils and doesn’t mind poor drainage. Pollinators love the flower nectar, and migrating birds benefit from the fruit.
Little Bluestem (Schizachyrium scoparium)
This ornamental bunchgrass has fine foliage that grows in dense, attractive mounds. It gets its name from the slender greenish-blue stems that reach up to 5 feet tall in the fall, then turn dark mahogany in color. The white seed tufts are very pretty and remain through winter.
As a mid-prairie species, little bluestem is native to open plains and pastures throughout the Midwest, east coast, and southern U.S. It tolerates drought but can’t handle standing water or wetlands. It also self-sows readily, so be sure to keep it contained by snipping off the seed heads in the fall.
Virginia Wild Rye (Elymus virginicus)
The fibrous roots of this wild perennial grass are wonderful at anchoring soil particles in a rain garden. Native to open woodlands and shaded banks throughout the midwestern and eastern U.S., this species is best suited to partially shaded areas with improved drainage.
The seed husks (“awns”) are sharp and are reported to harm dog paws and eyes, so don’t plant this in areas frequented by pets.
Arrowwood Viburnum (Viburnum dentatum)
This native deciduous shrub can grow up to 5-10 feet tall and enjoys moist yet well-drained soil. It grows naturally along streams, ponds, and bogs and produces pretty, flat-topped clusters of white flowers that butterflies and bees adore.
In the late summer, the clusters turn to bluish-black berries. The shallow, branched roots hold topsoil in place and provide a nice complement to tap-rooted species like black-eyed Susans.
Wild Bergamot (Monarda fistulosa)
Also known as wild bee balm, you probably know that Monarda species are incredibly beneficial to pollinators, but they are also highly adaptable. Wild bergamot enjoys consistently moist soil and doesn’t mind a little bit of waterlogging as long as there is no standing water. The lavender-pink flowers and aromatic leaves add ornamental value throughout the season and grow easily from seed.
New England Aster (Symphyotrichum novae-angliae)
Many people plant this wild aster simply for its vibrant purple blooms, so why not integrate it into a low-lying runoff collection area? Its resilience in moist conditions and deep root system is beneficial for preventing soil erosion and stabilizing the soil after heavy storms. Despite its New England name, it is native to almost all of the United States and is very easy to cultivate in a variety of climates.
Dogwood (Cornus spp.)
With their distinctively four-petaled flowers, dogwoods can grow as large shrubs to medium-sized trees. They thrive in full sun and enjoy moist yet well-drained soil. Red osier dogwood (C. sericea) is an awesome choice for northern areas, and Pacific dogwood (C. nuttallii) is ideal for western regions. In extra rainy areas, keep dogwood a little higher up on the margins of your rain garden, as these plants don’t do as well in low spots where water may pool up.
Blue Vervain (Verbena hastata)
The pretty spike-shaped flowers of vervain are remarkably flexible in the landscape. You can plant this flower at the base of a rain garden where the soil gets extra mucky or along a slope with medium moisture. Hardy in zones 3 to 9, this native perennial wildflower can also withstand periods of drought, but it may not flower as vibrantly.
Wild Geranium (Geranium maculatum)
This low-maintenance herbaceous perennial forms low-growing, slow-spreading clumps of pretty palmately lobed leaves. The colonies make an ideal ground cover in the moist open spaces of a runoff area and require little maintenance.
Adorable pink blooms appear in the late spring and early summer, attracting many native solitary bees and syrphid flies, which offer beneficial pest control. The fibrous roots and shallow taproot hold upper soil layers in place after heavy rain events, making it a nice complement to deep-rooted companions.
Nodding Onion (Allium cernuum)
This hardy, easy-to-grow perennial is widely adaptable to many sites in your garden, including sunny parts of a rain garden. It grows wild near streambanks and open areas throughout the United States.
The “nodding” allium blooms droop downward to protect nectar from heavy rains. It is just 8-18” tall and sturdy, making it a durable, low-maintenance addition to areas exposed to heavy wind or rain. It’s best to plant nodding onion with other perennials to hide foliage when it withers in late summer.
Foxglove Beardtongue (Penstemon digitalis)
The tall tubular spikes of beardtongue provide a striking display for a plant that is so low-maintenance. Foxglove beardtongue tolerates both wet and dry soil, adapting to a wide range of locations within a rain garden. This southern native plant particularly shines in areas with lots of clay and poor drainage. It doesn’t mind heat or drought and attracts hummingbirds during the summer.
Black-Eyed Susan (Rudbeckia hirta)
Black-eyed Susans seem to fit into just about every area of the garden. From pollinator and cottage gardens to ornamental beds to wildflower prairies and, yes, rain gardens, this is one of the most versatile and beautiful native species you can grow. It is technically only indigenous to a few states but has widely naturalized throughout the U.S.
From wet soil to long droughts, it doesn’t mind extremes and reliably produces bright yellow daisy-like flowers to liven up rain garden plantings. This is one of the most resilient plants I’ve ever grown, and it practically thrives on neglect.
Pacific Bleeding Heart (Dicentra formosa)
The delicate heart-shaped drooping flowers of bleeding hearts are dazzling in shady western rain gardens. This lush perennial is well-adjusted to wet weather and thrives beneath the canopy of taller plants.
The extensive deep rhizomes protect soil from erosion and help the plant withstand harsh winters. It is native to the Pacific Northwest but can be grown in shady, temperate rain gardens in similar climates.
Goldenrod (Solidago spp.)
You’ve probably noticed the bright golden-yellow spikes of goldenrod flowers blooming in late summer and fall across large swathes of pastures, prairies, and even swamps. This classic wildflower is widely adapted to North American gardens and is very forgiving of different conditions. Low-nutrient, dry soil? No problem. Poorly drained clay? Totally fine! Wet soil? Drought? No issue.
Goldenrod is often so willing to thrive in rain gardens that you must divide it every 2-3 years to control its spread. The flowers are particularly beneficial to bees, wasps, and butterflies. While some accuse goldenrod of causing seasonal allergies, its doppelganger ragweed is the real culprit. Still, some hybrids are available with sterile seed sand reduced pollen production.
Common Camas (Camassia quamash)
This western native wildflower produces striking purple star-like flowers from bulbous roots. The bulbs form shallow clumps that easily naturalize amongst grass and other groundcovers.
They enjoy the consistent moisture of a rain garden and go dormant during the summer to withstand drought. The plant naturally grows wild in moist meadows and along rivers and streams. Be sure to plant in the fall so there is ample moisture to help camas get established.
Joe-Pye-Weed (Eutrochium spp.)
This tall, robust plant is one of the more popular rain garden selections because it handles excess moisture with grace. The large, hardy plants love wet, rich soil and produce gorgeous pink flowers that attract a vast diversity of butterflies.
Yet they also tolerate dry conditions and provide nice winter interest with their unique seed heads. Despite its name, Joe Pye weed is not weedy and often becomes a showstopping favorite in rain gardens.
Coreopsis (Coreopsis spp.)
Sometimes called tickseed, coreopsis is an extremely adaptable wildflower that prefers moist soil but tolerates some drought. The rhizomatous root systems spread slowly, forming nice ground cover to prevent soil erosion. The sunshine-yellow flowers appear in spring and summer. Choose from annual or perennial varieties native to your region.
Deer Fern (Blechnum spicant)
If your rain garden is stuck in the shadows of your house or a tree, deer fern is a remarkable choice for occupying the low-light area and holding soil in place.
Ferns love moisture, acidic soil, and rich decomposing organic matter. This species is native to northern zones and stays fairly compact at just 2 feet wide and tall. It enjoys consistent water exposure and tolerates occasional puddling as well.
Purple Coneflower (Echinacea purpurea)
The famous echinacea wildflower is native to the eastern and southern states, thriving in the well-drained sandy or rocky soils of prairies and open woods.
This perennial works best on a sloping rain garden in regions that receive large rushes of rain at once and dry quickly. It won’t tolerate standing water, but it readily withstands drought. Don’t plant coneflowers in the lowest point of a rain garden, or they may rot.
Fiber Optic Grass (Isolepis cernua)
This wetland grass has a fine texture and little brown flowers that interplant nicely in rain gardens near your front sidewalk. At just 10-14” tall and wide, fiber optic grass is stout, mounding, and hardy. It is native to some parts of the West Coast but adapts readily to wet places, particularly low-lying spots in your yard. It enjoys sandy or peaty soil that does not dry out.
Blazing Star (Liatris spp.)
Also known as gayfeather, the whimsical blooms of Liatris are a pleasant surprise in a garden whose main function is to catch and filter rainwater. In the spirit of fashion, this flower lives up to the idea that functionality doesn’t mean we have to sacrifice style!
There are many species in this genus, some of which prefer dry prairie conditions. However, Kansas gayfeather (L. pycnostachya) and dense blazing star (L. spicata) grow in moist prairies and wet marshes, making them suitable for depressed areas in your landscape.
Swamp White Oak (Quercus bicolor)
An extra large rain garden in a low-lying yard should certainly consider a marsh-loving tree like swamp oak! This giant, well-shaped oak has gorgeous lobed leaves that turn orange-gold in the fall. It grows fairly slowly and enjoys some shade from a building, but it can reach up to 60 feet at maturity and penetrate amazingly deep roots into the soil. It tolerates both dry and wet conditions, even withstanding periods of standing water.
Unfortunately, swamp white oak is not great for urban rain gardens because it doesn’t tolerate pollution well. It is much better suited to suburban or semi-rural settings. Beware that the fruit (acorns) can be messy in your yard.
River Birch (Betula nigra)
Another large rain garden option, this tall native tree can reach 60-80 feet and tolerates excessive water, which is why it’s so often found growing close to riverbanks. The bark shreds in pretty pink and red peels, and the roots form a mat-like structure that readily absorbs rainwater.
These trees are great for rain gardens near the home because the roots are not a threat to the foundation of your house and will not become invasive. Instead, they are extra absorptive of gutter and roof runoff.
Blue Flag Iris (Iris versicolor)
Last but not least, this gorgeous iris has to make the list of rain-collecting plants. The showy blue flowers and graceful sword-shaped leaves are a delight in any garden but particularly thrive in wet areas.
Native to northeastern wetlands, Blue Flag iris doesn’t mind soggy soil and even tolerates complete submergence in the event of a major storm event. It is easy to grow and slowly spreads by self-seeding and rhizomes.
Biodiversity is the key to success in any garden, but especially in rain gardens. Combine many different plants that can withstand a diversity of moisture conditions and provide varying heights of foliage for ornamental interest and water-slowing capacity. Most importantly, try to diversify the root depths from shallow fibrous root zones to ultra-deep taproots that will stabilize soil and accelerate water infiltration.