Help me with this year's cover crop.

I want to cover crop all my gardens this year, as I harvest.  I need something I can plant here in zone 4b.  I don't care if it winter kills or not, as long as I can plant next year in late May/early June.  I won't be tilling it in, but as long as I can mow it short and plant it, or it simply winter kills, it's fine by me.  My soil conditions are heavy clay, and nitrogen deficient.  I have several new beds that I covered to kill the quack grass this year.  Normally I use tillage radish to help with that, and will probably incorporate that into whatever else I use.  Other beds have been planted for a year or two, but still need nitrogen badly.  I would welcome any suggestions to make my garden areas more productive for next year.  I'm not opposed to adding amendments like Azomite or whatever.  I have used Azomite in the past and will be using it on all new areas this fall.  Thanks for any replies.

If you want cover crops to produce more nitrogen in your soil then they can't be allowed to die during the winter. Cover crops need to have enough time to grow nodules for the bacteria that actually "fixes" nitrogen. The bacteria also need time to for this process. I would plant a legume like peas or something else like hairy vetch in the fall and mow and till before winter comes. That way your soil will be more rich in nitrogen when you plant again next spring.

Or you could possibly plant cover crops in the fall and let them die over the winter as long as they have a few months to create more nitrogen before the bitter cold and snow arrives.

Chris Giannini wrote:Or you could possibly plant cover crops in the fall and let them die over the winter as long as they have a few months to create more nitrogen before the bitter cold and snow arrives.

That is the plan.  I have had some things (hairy vetch is one) that came up again in the spring, but most things winter kill here.  I have fall and early spring to get as much nitrogen in the soil as I can unless I plant a good nitro-fixing/ground-busting cover crop in half the gardens this fall and next spring and leave it growing until I can chop and drop it with the idea that I just don't use those gardens for a year.  I'm not against that idea either.  I'm pretty much open to anything that will improve these garden plots.  

I have one area that I talked about in another thread where I just planted every seed I had extras of, but that was mainly to get a lot of roots in the ground and start feeding the soil.  

I guess being in zone 4b doesn't really change anyone's recommendations?  In that case, I'll go with Redhawk's suggestion in another thread and plant clovers, daikon radish, brassica, and alfalfa and let then grow as much as they can grow before winter.  I will probably add in some peas and vetch as well.  Next spring I may do the same thing to the same beds and just plant my annual gardens in new, composted beds, mowing the cover crops as they grow with the idea of planting in them the following year.

Todd,  this link might be of use to you for cover crop choices in zone 4.

cover crops

Redhawk