What is the problem?
Clay soil is a problem for many gardeners throughout the United States including those in the tri-state area.  It is easily recognizable by being slippery and sticky when wet and extremely hard when it is dry, sometimes cracking during the summer.  Clay soil is made up of extremely small particles that are close together with not much space in between.  Clay particles tightly stick together not allowing air or water to pass through it. 

Rich compost is on the left and clay soil is on the right.

What is the damage?
A wide range of plants is able to survive in clay soil, but there are few plants that can really thrive.  Since moisture cannot easily pass through clay particles, water does not drain from the soil very well.  Plants have problems penetrating the tight soil with their roots.  Additionally, the roots often start to rot since the water takes so long to drain, causing problems for the gardener.

What can you do?
There are a few options for dealing with clay soil.  A gardener can plant clay-tolerant plants, build raised beds on top of the soil, or try to improve the clay soil so that any plants can survive in the soil.

There are some plants that thrive in sticky, dense clay soil.  This includes quite a few trees and shrubs such as bald cypress, ash, and dogwood, as well as many perennials that do well in the poor soil.  Some of these perennials include some well-known favorites that you may already have in your yard:  Echinacea (coneflower), Coreopsis, Aquilegia (columbine), Dianthus, Heuchera (coral bells), Hemerocallis (daylily), ornamental grasses, and many others.  For more information stop by Delhi Flower and Garden Centers and talk to a horticulture expert on plants that are clay tolerant.

Instead of being required to stick with clay-tolerant plants, another easy option for dealing with clay soil is to build raised beds.  Make large mounds of soil comprised of three parts of topsoil and one part of well-rotted compost or manure.  Before piling on the topsoil, be sure to cut away the sod if a flower bed is not already in place.  Mound it up on top of the clay soil, assuming that in the next few years it will settle a little bit.  This also works well when planting around tree roots.

An example of a simple raised bed.

There are several misconceptions in improving clay soil.  Probably the biggest one is to add sand in order to aid with drainage.  Sand actually has the opposite effect, creating an even harder soil that rivals something like cement.  The best solution to improving the soil is to gradually mix in rich, organic material.  The organic material will eventually work to loosen the soil, improving its structure and allowing more water to drain through it.  For more information on other products that help to loosen clay soil, visit the Plant Pharmacy and talk to our experts!