Daikon radish is very good at breaking up hard soil. http://www.groworganic.com/seeds/cover-crop.html is a good resource.

thanks Dak, for that link. Do you think I can plant something now or would it be better to wait for warmer weather?

I think planting now would be great! A lot depends on what you end up planting, regarding your question on whether to till first. When I used daikon I just threw the seeds out, they did great; when I used the Soil Builder Mix I rototilled first.

Has anybody had experience using sunflowers as a cover crop? I think I read somewhere that their roots are good at breaking up the soil. I don't know if they would provide the nitrogen that other cover crops do though.

It could be striking to have a front yard filled with sunflowers.

You should check out Peaceful Valley's cover crop page--at teh left you can narrow it down by what you are looking for, i.e. loosens compacted soil, etc.

Carla in Sac

Here is a link that might be useful: http://www.groworganic.com/seeds/cover-crop/annual-cover-crops.html

I would definitely recommend Peaceful Valley. They have charts for time of year, whether you want to loosen soil, create bulk for tilling in, etc. I grew hulless oats from them just for fun, and they did great!