best overwintering cover crop to smother weeds

Asked September 24, 2013, 8:46 PM EDT

I have a large garden plot of very fertile soil that because of mismanagement by a tenant became infested with pigweed and grasses. I mowed everything and kept it covered with tarps all summer and just retilled the soil. (All the surface growth was dead but I know there are weed seeds and roots under there.) What are some good suggestions for overwintering cover crops to choke out weeds this fall and in the early spring. I plan to till the first cover crop in and plant another cover crop in the late spring. In the past, crimson clover, buckwheat, and Australian field pea have all done well as cover crops in this soil. And, how thickly should I sow it for maximum weed smothering? Thanks very much.

Polk County Oregon

1 Response

Good afternoon and thanks for your question. You did a good job of minimizing weeds by covering the garden area this summer. However, when you tilled, you most likely exposed more seeds, as you probably already know. Adding a winter cover crop is a good idea and your choices are very good. Try to plant very soon because soon the weather will be cooling down and they won't have enough time to establish. You may get some weed germination next spring even with the cover crop, so covering the area between rows with straw (look for wheat straw with minimal seeds) or use plastic or ground cover or ground cloth if you need to. You might be able to continue to kill weed seeds as they come up but covering the area not in actual cultivation with clear plastic, which will help kill them through "solorarization" similar to the process you used this year. Good luck! Please feel free to ask additional questions. Linda