You're welcome Green Please. Every area is different though. Check with a farm in your area too. They would definitely know which cover crops grow best in your area. Whatever you plant don't let it go to seed. Then it'll regenerate. I think before a cover crop is planted you want to work the soil and add things like peat moss, cow manure etc. Fall is the best time for soil preparation. If you can get a nice well drained soil ready in the fall that means it is easier to work in the spring. I'm not familiar with N Ca. climate. It doesn't really matter if your ground freezes like mine soil with lots of organic matter can be worked faster. If winter brings rains and soil is wet in the spring then soil with lots of organic matter can be worked sooner. You don't want to work wet soil ever. The other benefit of a cover crop is you protect the soil from soil erosion. To really till it under you might have to rent a rototiller. I use a mattock but if you're not used to that sort of work(who is in the spring)it can be quite laborious. I personally love tiling by hand. Great exercise. I recommend Warwood mattocks, the best.