Wednesday, 30 March 2011
I think I will bring up this subject again, as I am fond of the subject and think more gardeners should use it.
What is a cover crop? A cover crop is a crop that is planted simply for the purpose of the soil. Wether you cut it and compost it aside from the soil, or you till it under is up to you.
When do I plant cover crops? It depends on the cover crop. Typically cover crops are grown over winter, usually a vetch and rye, as they can withstand cold temperatures. The reason for doing it over the winter is because the winter months are when you don't have much else planted, so you are not taking away space from your garden. The other reason being that during the winter months erosion tends to happen because nothing else is growing to hold down the soil. So, a cover crop holds down the soil, takes up nutrients, fixed nitrogen (if a legume) and adds organic matter.
However, some good cover crops can only be grown in the summer, when it is warm. Those include certain varieties of vetch (Chikling vetch fixes nitrogen in 45 days!), soy beans (good nitrogen fixing crop, and lots of organic matter), alfalfa, and certain kinds grains and smother crops.
When or why should I grow cover crops? I think the best way to start out is to grow a mix of vetch and rye over all of your garden over the winter. In the spring time till it under. I recommend also that you set aside part of your garden each year (you decide, wether it be half, a quarter, all of it every 4 years?, etc.) during the spring and summer to grow a summer cover crop. Growing cover crops every winter and every summer will result in a build up of good soil much faster than if you don't sow cover crops. Growing rye has shown that weeds are less likely to grow in that soil. Also, growing something like mustard and other cover crops is a great way to smother out weeds for a season before planting. Resulting in less weeding, and less herbicide (if that is really necessary).
How much do cover crops cost? Typically grains are the cheapest, and if you buy it by the 5lbs the cost drops quite a bit. Some vetch and other legumes are a bit more costly, though, worth it in the long run.
So, what does it take to get started? Most big seed companies will sell cover crops ranging from sunflowers, to mustard, with grains and legumes in between. A cover crop will keep weeds from growing in your soil, can add nitrogen and organic matter and improve your soil greatly!
Johnnys Seeds is where I've ordered cover crops in the past, they have pretty good prices, and the quality is good. http://www.johnnyseeds.com/c-4-cover-cropsfarm-seeds.aspx