Q. When should I prepare the soil in my garden? What about tilling in the Fall versus the Spring? And I’ve even heard you shouldn’t till at all because it makes the soil too fine and hurts the beneficial soil organisms. Also, should I “let the soil rest” before planting? I’ve heard this is something I should do.
A. You may hear that the soil should be tilled in the fall, and then you can plant in the spring without tilling. Also, some people will insist that a tiller is “bad for the soil structure” because it breaks up the soil particles too finely, and that you should only use a shovel, or plow, etc. And some folks are avid “no-till” gardeners, believing you shouldn’t disturb the soil at all, with it’s layer of sod and beneficial soil organisms, but rather, just poke a hole for your new seed or seedling, and let it compete with the existing situation for survival.
Please consider the counsel of Dr. Mittleider as follows:
We have never been able to discover any harm to the soil from the action of a roto-tiller. On the contrary, our experience has been that the better job that is done in breaking up the large soil particles into small ones, the better the soil is for new seeds and seedlings.
Tilling in the fall – either with a roto-tiller, shovel, tractor, or whatever means you have at your disposal – puts clean, healthy plant materials back into the ground where they can compost naturally through the winter. That includes any weeds that have managed to survive your vigorous weeding efforts, thus preventing them from wintering over. There are other benefits as well, including having the freeze-thaw cycles break up the clods and improve the soil tilth.
Failing to till again in the spring gives the weed seeds that are always in the ground, just waiting for favorable conditions to sprout, a substantial advantage over the vegetable seeds you are just planting. The same holds true for preparing your beds and then waiting several days before planting. Always prepare your soil beds immediately before planting, so that your vegetables have an even start with the weed seeds.
No-till farming has proven to be beneficial in certain situations, such as places where erosion can remove the topsoil. And it works well in the grain fields of places like Montana (where the best wheat I’ve ever used is grown by Wheat Montana Farms using this method). However we do not recommend it for your backyard garden, for several reasons – and since erosion is seldom a problem in that setting hopefully it won’t tempt you too much.