I recently had a reader ask what to do with clay soil in her garden and I promised I would write about it for her and the rest of the gardeners in Indiana.
You might wonder if you have clay soil or not and I can just about guarantee you that you do unless you were lucky enough to have purchased a home where the previous owner amended the soil for you. I’ve had several homes in this wonderful State and every one of them had heavy clay soil. Trust me, when you want pretty flowers and luscious vegetables they are not going to work well in clay soil.
How do I know if my soil has clay content?
You could have it tested but you can determine it for yourself, too. Dig a hole. If you can take that soil and form a ball with it…it has clay. Another hint would be when you dig or till the soil sticks to your shoes or boots and your spade or shovel. Although clay is wonderful for pots to be made from it is not so great for most plants to grow in. Why is that? The clay content in soil is dense and hard for the small roots of most plants to grow through. It also hold moisture really well and that is not always such a good thing. It can cause some plants to actually rot from too much moisture.
Breaking Down The Clay
So, what do you do? Can anything be done? Yes, it is going to take some work but you can get your soil in a condition to grow things and in the very first season, too. Let me just say something first, if you have read or been given advice on treating one hole at a time; do not take that advice. In essence what you do with that method is you create an outdoor clay pot. If you only treat the soil where you are growing one plant the plant will do nicely for a while. The surrounding clay will cause it to eventually start to curl around in the good soil because it can not penetrate the clay. You virtually get the same thing as a potted plant that become root bound. So, just don’t do it.
Instead do an entire area at once. You can dig it by hand or use a tiller. Personally, although back braking, I like the good old fashioned shovel in hand method. For really large areas the tiller works but I don’t think as well as concentrating on an area with the shovel. You get a better mixture with less big clumps of clay to work with.
If you are going to be working in an existing bed, you will need to remove the plants that you want to keep before you start working the soil. Don’t worry, you will get to re-plant them when you are done. You are going to want to add about 6 to 8 inches of organic matter to your area. Break up the clay soil with your shovel and then add the organic matter. It can be just about anything you can find. Grass clippings (not treated with any chemicals), compost, or shredded leaves work very well. You will want to spread the organic matter over the soil and then start to work it in so that you have about 6 to 12 inches of the mixture of old clay soil with the new material you have spread around. The area will be a little taller than when you started but it will settle over time.
I like to work the soil, wet it and let it sit for a day or two. Then I go out and mix it up one more time. After that, my old and new plants can be planted. I also add another mixture a couple of times throughout the growing season; about mid-way and towards the end of the season. After a couple of years of doing this, the clay won’t be much of a problem anymore.
Clay soil that has not been helped along has a tendency to be on the alkaline side so adding some acid to the soil will also be beneficial in most cases. Unless I have true acid loving plants to treat the soil with, I typically apply the acidic food at half the strength. It is hard work in the beginning but you will never regret putting in the effort because your flowers and vegetables will grow better and produce more.