How do I deal with red clay soil?
Q. “We’re new to this area…and RED CLAY! It’s not like it was where we came from. I talked to a neighbor who recommended I talk to you – an expert – on dirt. I hope you can help us be able to plant and grow instead of kill! Thank you!”
I appreciate the recommendation, and your email, but I’d like to correct one word…” expert”. I really don’t know any. The folks I’ve gleaned from and looked up to, thru the years, would say they’re “life-students, not experts”. I’m humbled by what I learn, and the older I get, the more I realize how MUCH I have yet to learn. I won’t live long enough!!
Nature is a living, ever changing entity. Some things that were thought to be set-in-stone 50 years ago, we now know are, at best, ineffective, and at worst, harmful. Even 25 years ago I taught what I knew, and I’d like to have a chance to go back and recant. No one, in my opinion, is an “expert” when it comes to Nature.
Red clay is amazing! You need it to build an earthen dam, make bricks, set a foundation on, build a manmade pond, but many dirt-folks have been driven to profanity when trying to work it. It’s made up of very fine particles and not a lot of organic matter. This leaves us with a soil that’s sticky, dense, and drains poorly. It can “heave” in winter and be slow to warm in spring, and compacts easily making it hard for roots to spread. Did you know that clay is also the most nutrient-dense soil? It’s a vault of all good things plants need but can’t access…until some organic matter is mixed in.
From your email I gather that you dug holes, and set the plants with “good soil”, then mulched and watered. What you did was create an in-ground flowerpot…with no drainage. The plants will be ok for awhile, as long as there are no environmental challenges such as drought or days of heavy rain. The roots will grow until they hit “a brick wall” then they struggle to find a foothold or placement. If they can’t penetrate the clay wall they’ll invert and/or die. In the case of too much water, the planting hole acts like a cereal bowl, holding all the water around the roots. The plants suffocate, rot, and die. This could take weeks, months, even years, depending on the species. What to do?!
We’ll stick to landscape plants today, and it’ll be best if you work an entire area rather than digging individual holes. If it’s a new area to be planted or an old, overgrown one, the process is similar; organic matter is needed. If you aren’t pushed for time, cover the area with layers of paper or cardboard and mulch deeply. The bacteria, fungi and insects in the soil will work wonders over a season or longer.
Time is important? I’m not a fan of deep soil disturbance but in this instance it’s necessary. Layer on 6”-8” of compost, rotted sawdust, composted manure, or any other good “rot”; if you can use a shovel to cut and mix, that’s great, but if you physically can’t, use a tiller ONLY for cutting and mixing, not pulverizing. The consistency, to a depth of about 12”, should be a crumbly, but will hold a form if pressed. I like to water it well and “let it rest” for a couple days. The soil will settle and will be easier to firm around new roots.
With clay soils it’s best to stick to plants that have adapted to the soil and climate of the area they’re being expected to thrive in (a.k.a. native plants). Any Tennessee dirt-person can help you with that, and probably give you a few starts. You can also find tons of native plant info at most garden centers. STEER CLEAR of “exotics” or delicate species until you get the feel of your conditions.
Mulching is essential, and doing it correctly is too.
Make a PLAN (on paper) BEFORE you begin, and plan for the long-haul. Plant-shop with a list, and stick to it. No “impulse” buys. Get your counsel from a seasoned dirt person, not from the latest magazine.
Sherrie Ottinger, The Tennessee Dirtgirl
