Plants for Problems Places: Clay Soils

Winter is a good time of year to consider what to do with areas of your yard where plants don't grow well. These problem places could be due to a variety of reasons such as poor soil, extreme weather exposure and slopes. In this blog, I'm going to tackle what to grow in heavy clay soil. 

We garden in a clay pit. Well, maybe it's not that bad, but heavy clay soil dominates our landscape. Clay is fertile and great for growing grasses and many plants, but the small particle size of clay soils means it stays cool and wet longer, opening up the possibility of root rot diseases. It's imperative that we plant the right shrubs, trees and perennials in the right location.

We learned this the hard way. We have a knoll on our property where my wife and I thought a beautiful flowering, small tree would be perfect. Even though it has clay soil, we assumed the knoll had better water drainage than the other parts of our yard. But even after trying to grow trees that normally tolerate clay, such as redbud and dogwood, on that knoll, they invariably died after a few years. We realized that even though it was a knoll, it still had poor water drainage. So, we shifted our thinking and expectations and planted a willow. It's beautiful and even though we don't have the flowering tree we wanted, we do have a healthy tree that's graceful and great for wildlife.

If you have clay soil, you can try to amend it annually with compost or build raised beds on top of it. That will help. But to ensure success, plant trees, shrubs and perennials that can tolerate growing in clay. Here are some of my favorites.

For trees, try Show Time^™ crabapple (Malus x). It features thick clusters of fuchsia pink flowers in spring, great fall foliage color, and berries for the birds. Polar Gold^® arborvitae (Thuja occidentalis) is a hardy native evergreen that grows in part shade and has golden tipped branches. Spring Glory^® serviceberry (Amelanchier canadensis) is a durable, dwarf, native tree that blooms early with white flowers and has colorful fall foliage.

For shrubs, try Ginger Wine^® ninebark (Physocarpus opulifolius), a disease resistant native variety with burgundy colored foliage, white flowers and red seed heads. Happy Face Yellow^® potentilla (Potentilla fruticosa) is a long blooming, yellow-flowered shrub that's salt tolerant and deer resistant. Berry Poppins^® winterberry (Ilex verticillata) only grows 3 to 4 feet tall with bright red berries from fall through winter. This tough native tolerates wet and clay soils with ease. It needs a male winterberry like Mr. Poppins^® planted within 50 feet for pollination to occur so berries can be produced. 

For perennials, check out the Decadence^® series of false indigo (Baptisia hybrid). Choose from 11 different colors in the series, all bearing blooms that bees love in the springtime. False indigo is a highly drought tolerant perennial that is very long-lived. Luminary^® ‘Ultraviolet’ tall garden phlox (Phlox paniculata) bears deep magenta flowers in the summertime that butterflies adore. 'Chantilly Lace' goatsbeard (Aruncus) thrives in part shade and produces sprays of lacy textured, creamy white flowers in early summer. It looks similar to astilbe but is more drought tolerant.