The steady rains and high humidity we’ve been experiencing can cause some perennials to rot, especially in heavy clay soil with poor drainage, explains Leah Blanton, Project Manager of the PHS Public Landscapes team.
When the soil stays wet, there is a risk of phytophthora, a water mold which will rot plant roots, and other fungal or bacterial diseases. Improving your soil drainage by adding grit or gravel in areas where you would like to plant drought-loving plants can help alleviate some of these problems, Leah advises.
Sometimes, however, changing your soil structure on a large scale is often difficult and costly. Trying to work with what you have is always a better way to go. If your soil stays wet after a deep rain and doesn’t drain quickly, try planting perennials that don’t mind wet feet. There are many perennials for both sun and shade that will thrive in wet conditions.
The following plants are all native, prefer full sun, and will attract many pollinators. Hibiscus species can be fully submerged in water and many produce dinner-plate-sized flowers that come in a range of colors. Asclepias incarnata, Swamp Milkweed (pictured above), can be planted in wet areas and provides a habitat for Monarch butterflies. It has beautiful pink flowers and interesting seed pods. Eutrochium purpureum, Joe Pye weed, is a tall, native perennial that thrives in water margins and moist conditions. Its flowers persist into late summer and attract butterflies.
For part-shade conditions, natives like Lobelia cardinalis, Cardinal flower, is a resilient and attractive plant for wet areas. Their flowers are bright red and attract hummingbirds. Carex species are great native groundcovers that thrive in wet areas. Carex muskingumensis, palm sedge, produces interesting palm-like radial foliage. Carex crinita is a larger species that produces interesting, drooping seed heads. Carex stricta, tussock sedge, and Carex amphibola, creek sedge, are both great clumping sedges for moist areas.
PHS uses these plants in the 150 acres of free public gardens it manages throughout the city of Philadelphia. The right choices create sustainable, beautiful environments whatever the weather.