Clay soil is the bane of garden plants. Firstly, clay doesn’t drain well, staying a slimy-wet muck that rots plant roots. Plants that like well-drained soil — and most of them do — will fail to thrive or, more commonly, just die. As if wet clay isn’t bad enough, when it finally dries, it’s brick-hard, compacted, airless and resists absorption of water.
If you’ve ever tried to dig a hole in clay you know how unworkable it can be. If it’s wet, it clings to your shovel in great globs and is nearly impossible to chop up into fine chunks. If it’s dry clay you might not get your shovel into it at all!
You’re not alone if you’ve thrown up your hands in surrender — clay soil makes up about 10 percent of the soil across the U.S. The good news is that there are plants that can tolerate the extremes of clay soil. Also, there are ways to fix clay to make it hospitable to plants less hardy.
Some shrubs and trees manage to flourish in clay, even heavy clay, their roots resolutely drilling through it millimeter by millimeter. There are also very hardy prairie grasses that have adapted to the harsh conditions of clay. But the delicate roots of annuals, hybrid perennials and vegetable plants are mostly not up to such a tough challenge. The good news is that some particularly rugged native plants have adapted to the harsh conditions of clay. We’ve listed several here that butterflies, honeybees and birds will want to visit.
Improve the texture of your clay soil and you’ll be able to plant even more species of plants. Mix in organic matter, such as mulched leaves, compost, wood mulch, gypsum and cottonseed hulls. Position plants so the top of their root ball is slightly above the top of the soil in your garden — this will help prevent their suffocating in the event the clay stays too boggy even after you’ve improved its texture.