Water Loving Perennials

Marsh marigold, an American native wildflower, blooms in early spring.

Garden locations that drain slowly, often with a soggy or shallow collection of rainwater, provide ideal conditions to grow water-loving perennials. Gardeners sometimes colloquially use the term "wet feet" to illustrate these plants that like their roots in boglike conditions. Depending on the plant species, choose from plants that grow best in shady conditions and in any increasing amount of sun exposure. Often, the wetter the soil, the more intense sunlight rays a plant tolerates. Match the perennial plant with your climate, too, as winter cold is a central factor that limits a plant's ability to return in spring.

Characteristics

Sweet flag is an iris species that lives in saturated soil conditions.

Not all common garden perennials plants adapt to growing in wet soil conditions. Typically plants best suited to soggy garden spots are those native to wetlands, stream banks or regions that receive abundant annual rainfall. Water-loving perennials don't necessarily need to be growing in shallow standing water, but they certainly grow and perform best if the soil never becomes even slightly dry.

Plant Examples

If grown in soggy soil, calla lily plants tolerate much more direct sunlight.

When looking for plants that tolerate wet soils, you can find them listed under many categories, like "marginal perennials," poorly-drained-soil plants" or "bog garden plants." "An Illustrated Encyclopedia of Perennials" mentions about 60 different species that prosper in wet soils. It includes marsh marigold, false spirea or astilbe, sedge, Louisiana iris, cardinal flower, forget-me-not, calla lily, bugbane, meadowrue, plantain lily or hosta, pickerelweed, arrowhead, Siberian iris, sweet flag, beebalm, rodgersia, bigleaf ligularia, blue quamash, and chameleon plant. Many ferns acclimate well to soggy soils, such as lady fern, royal fern and cinnamon fern.

Soil Considerations

Clay soil retains moisture longer than sandy soil.

Keep in mind that the type of soil affects how much moisture remains available for perennial plant roots. For example, a sandy soil drains water considerably better and faster than a loam or clay soil. To improve water retention, add organic matter to a sandy soil to slow the percolation and seepage of water downward and away from plants. Conversely, if a clay soil floods too readily, adding coarse organic matter also improves drainage. Two inches of rain create different growing conditions in a sandy soil area as compared to a clay soil zone within your garden.

Site Manipulation

Plant cattails in flooded soil, not in upland areas where soil is progressively drier.

Within the garden, the soil doesn't usually drastically change from dry to wet -- there is a change in grade and degree of wetness of soil in the topography. Buildings, gutters or man-made drainage courses like swales or ditches create more localized areas of wet soil. Regardless of the situation, the gardener can use a wide variety of wet soil-loving perennials, siting them in conditions that best suit them. In the wettest areas, where shallow water often pools for days after rain, plant perennials like rushes, cardinal flower or pickerelweed since they appreciate water. In slighter drier areas, where standing water isn't common but the soil is still mucky, plant other species. Transition to plants that do not like wet soils at the edges of the area, so you have a nicely blended composition of perennial plants in a continuum across the garden design.

References

• "The Illustrated Encyclopedia of Perennials"; Professor Marshall Craigmyle; 2002
• Canadian Gardening: Water-Loving Native Plants

Resources

• Canadian Mortgage and Housing Corporation: Rain Gardens: Improve Stormwater Management in Your Yard
• Learn2Grow: Plant List for Poorly-Drained Soil Moisture