How to garden in clay soil

Q. How do I get plants to grow in clay soil?

Floyd from Petersburg

A. Unfortunately, many of the commercially available plants don’t love growing in clay soil. But clay soil is what most of us are stuck with in the garden.

Clay soil is difficult to work with because the clay particles are so tiny. They hold onto water longer (which can be good and bad). Clay soils have less space for oxygen that roots need. They tend to be compacted, leaving plants to develop shallow root systems. This makes plants more susceptible to drought conditions and impacts overall plant health.

So the first thing you can do is amend the soil to grow the plants you want to grow. The best way to amend clay soil is to add organic matter and mix it in. This can be in the form of compost, manure, peat moss, cover crops and more. Compost can be added in the spring, but organic matters are best applied in the fall to allow microorganisms to multiply for healthy soils and proper nutrient levels of the current soil. Many of us build raised beds in clay soil to allow our new plants to have better drainage and more room for root growth.

If you don’t want the work of amending, you’ll at least need to improve the surface drainage in the area by creating swales (that start with shallow trenches). Even the plants that grow well in clay soil need some help with drainage. As water flows away from the area, you can widen the shallow trench to make a natural flow of water on top of the ground. This will help reduce ponding and drain the area more quickly. More information on swales can be found at http://go.osu.edu/swale.

As for plants that grow well in clay soil – there are tons of them. For shrubs, willow, serviceberry, winterberry, juniper, currants, spirea, viburnum and more will tolerate the conditions. For trees, some maples, birch, ginkgo, honeylocust, Kentucky coffeetree, crabapple, Norway spruce, elms and others will grow well.

The list of perennials is not super long, but there are still many. They include columbine, asters, daylilies, sedums, Russian sage, bee balm, sedums, and purple coneflower to name a few.

For more information, visit http://go.osu.edu/treesshrubsclay and http://go.osu.edu/perennials4clay.

Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are 9 a.m. to noon Mondays and Thursdays.