I just read through this article from a
local university to get an idea what cover crops would do well in my climate:
OSU Cover Crops for Weed Management
In one of the studies they combined radishes, peas, and rye. I love this idea! I think I'll do a fall cover crop over existing
lawn to prepare it for a spring vegetable garden. My soil tends rather heavily towards clay, so in my mind the radishes will break up the clay, the peas will provide nitrogen, and the rye much needed organic material and in the spring mulch.
Even better, my local library has radish seeds and
pea seeds for free, so I will only have to purchase the rye seeds.