Master Gardener: Composting with leaves
By Donna Tatting, Chisago County Master Gardener—
Unlike most years, this fall my leaves literally dumped upon my lawn instead gently falling over the course of several days. Luckily, I live on the edge of a swampy lowland so if the wind doesn’t do it, we can just get out the leaf blower and directly blow them into the swamp. We do, however, run the lawn mower over a good deal of them to use for protective winter mulch and I also fill my compost bin with them because leaves make great compost.
Pound for pound, the leaves of most trees contain twice as many minerals as manure. Since most trees are deep-rooted, they absorb minerals from deep in the soil and a good portion of these minerals goes into the leaves. Actually, these multi-colored gifts from above are most valuable for the large amounts of fibrous organic matter they supply. Their humus-building qualities mean improved structure for all soil types. They aerate heavy clay soils, prevent sandy soils from drying out too fast, soak up rain and check evaporation. So leaves make great composting material.
I use a county distributed compost bin, but truly, a compost pile can be just that … a pile. You may want to at least surround it with something like chicken wire to contain the pile. Some people complain that they have no luck composting leaves. “We make a pile of our leaves,” these people say, “but they never break down.” That is indeed a common complaint. So to accelerate the process, you should try and mix in nitrogen. Manure is the best nitrogen supplement, and a mixture of five parts leaves to one part manure will certainly break down quickly. If you don’t have manure—and many gardeners don’t—nitrogen supplements like dried blood, cottonseed meal, or bone meal work almost as well.
The second thing to do to guarantee leaf-composting success is to grind or shred your leaves. lt will make things simpler for you in the long run. A compost pile made of shredded material is really fun to work with, because it is so easily controlled and so easy to handle. Turn the heap every three weeks or sooner if you feel up to it. If you can turn it three or four times, before late spring comes, you will have a fine compost ready for spring planting use.