Solutions to drainage problems sometimes take the form of installing dry creek beds or drainage systems, such as French drains, but another possible route is simply to use suitable specimens (i.e., plants for wet areas). Many naturalized and native plants have evolved to grow in wet soils, so they're natural landscaping solutions to poor drainage problems.
"Native" is, of course, a relative term. After all, except for hybrids and cultivars developed by humans, every specimen is a native plant somewhere. A major criterion for inclusion in my picks for top plants for wet areas is cold hardiness: entries on this list are generally hardy at least to zone 3.
Since the objective is to find hardy plants for wet areas, it should come as no surprise that many of these specimens are wetland plants in the wild. Some of these specimens you won't find at just any nursery. But if you conduct a web search for "wildflower society" followed by the name of the region in which you live, you may find someone who specializes in the sale of native plants for your locale.
For those who prefer images to words, I have also drawn a sample landscape plan for wet areas. Though based loosely on the discussion here treating native plants, I do include one exotic plant in my drawing as well: the popular tropical specimen, elephant ear plant.
Examples of Native Plants for Wet Areas
Black chokeberry (Aronia melanocarpa) is a white-flowering bush of approximately 4'x4' dimensions. But its mid-spring flowers take a back seat in importance to its fall attributes. The leaves of these Eastern North American natives become purplish or reddish in autumn. The fall foliage is complemented by the namesake berries. Although bitter-tasting to some human palates, the berries, which remain on the shrub into early winter, serve as an emergency food source for birds. Arrowwood viburnum shrubs provide another example of a white-flowered specimen with excellent fall foliage and pretty berries that is suitable for wet areas. Aronia melanocarpa is relatively tolerant of wet soils, making it a "living solution" to drainage problems.
Winterberry hollies (Ilex verticillata) are native plants in Eastern North America. Their natural habitat is wetlands -- an attribute you can exploit if you're looking for something to grow in those problematic swampy spots in the yard. Winterberry holly likes ground on the acidic side, as you would expect from a swamp plant.
Winterberry bushes can be grown in partial shade or full sun, but you will probably get superior berry production in full sun. Winterberry holly is dioecious, which is another fact to keep in mind for berry production. Height and width will vary greatly, depending on growing conditions, but a rough average is about 9' x 9'. The berries of this shrub attract songbirds such as the bluebird and game birds such as quail. Unlike the holly mentioned next, winterberry is a deciduous shrub.
Inkberry bush (Ilex glabra 'Densa'), a native plant in Eastern North America, is a more typical holly: it is evergreen. Reaching as much as 8 feet tall at maturity, it bears a blackberry that gives this shrub its name. Clump-forming with shiny leaves, inkberry holly (Ilex glabra) prefers full sun to partial shade, with an acidic soil.
Like the plants already mentioned, pussy willows (Salix discolor) are wetland plants in nature, making them excellent plant choices for wet areas on your landscape. Pussy willows are deciduous shrubs that can reach a height of 20', but they can be pruned back to keep them shrub-sized. Like winterberry holly, pussy willows are dioecious. Salix discolor is indigenous to 27 states across the northern half of the U.S. from Maine to Montana, and as far south as North Carolina.
Sweet pepper bushes (Clethra alnifolia) are wetland plants that produce fragrant white blooms in July and August. The flowers of these wetland plants appear on 8" upright spikes. Sweet pepperbush can be grown either in sun or shade and reaches a height of 6'. The bush is indigenous to 20 states in the eastern U.S., ranging from Maine to Texas.
Must-haves on this list are the dogwood shrubs renowned for their vibrantly-colored bark. For example, red osier dogwood (Cornus sericea), which is native to 31 states in the northern U.S. (including Alaska), is valued for the red color of its bark, as its common plant name suggests. Other examples include:
Meadowsweet shrubs (Spiraea latifolia) are wetland plants indigenous to 18 states in the northeastern U.S., ranging from Maine to Minnesota and as far south as North Carolina. Meadowsweet tolerates all soil types except heavy clay soils. Its white floral spikes waft pleasing aromas from June to September. These 4' wetland plants are members of the rose family.
Horsetail plants can be grown in a wide variety of habitats, including those where the soil is damp. They are aggressive spreaders, so do not plant them unless you really want them.
I've saved the best bloomers for last -- specimens desirable as water garden plants. I head the list with leopard plants because I like the total package they bring, which includes the following qualities:
- They produce blooms that are not only attractive but also quite interesting
- Their leaves are attractive, as well
- They are good perennials for shade but will also take some sun (with sufficient irrigation), giving you a level of flexibility
Wild bergamot (Monarda fistulosa) is a close relative of a perennial sold at nurseries: bee balm (Monarda didyma). It is a fine choice for water garden plants in hardiness zones 4-9. This member of the Mint family bears lavender (most commonly) blooms in July and August. The flowers are tubular and grow in rounded clusters. Wild bergamot likes soil that is slightly acidic. Height up to 4'. Grow in full sun to partial shade. Wild bergamot is widespread in the U.S., being indigenous to every state except Alaska, Hawaii, Florida, Washington, California, and Nevada.
Marsh marigolds (Caltha palustris) are an early-spring bloomer. If you've ever been hiking through the woods in spring and encountered their cheerful yellow blossoms while traversing swampy ground, it won't surprise you to hear me proposing marsh marigolds as potential water garden plants. They will even grow in a bit of standing water, as will purple pitcher plants; the latter make an even better specimen in water gardens because they offer longer display value. Trout lilies and blue bead lilies, both of which also flower in yellow, grow in damp ground in the wild and can be located in moist spots in your native-plant garden. Continuing with the yellow theme, as tempting as it may be to grow yellow flag (Iris pseudacorus), be aware that it is a non-native invasive plant; a native choice for a wild iris is the Northern blue flag.
If you need water garden plants of a taller stature, Joe-Pye weed may be a good choice. It can attain a height of 6 feet and bears mauve-colored flowers. If you have a large area to fill in, you may wish to grow Joe-Pye weed the way it grows in nature, namely, in masses. At the opposite end of the spectrum (i.e., a plant that stays short) is white-blooming bunchberry.
Finally, use cardinal flowers (Lobelia cardinalis) as water garden plants if you crave a showy scarlet-red bloom that will turn heads. Its tubular flowers grow on spikes. Bloom time ranges from July to September. Cardinal flowers have been known to reach 4' if grown in the sun; in partial shade, they stay shorter but are still attractive specimens as water garden plants. Cardinal flowers are native to all of the lower 48 states in the U.S., except for Washington, Oregon, Idaho, Montana, Wyoming, and the Dakotas.
The USDA Plants Database has been helpful in compiling this list of native specimens suitable for wet areas and for use as water garden plants.