I' d say try winter wheat and winter hardy rye. Around here the farmers use wheat as cover crops and usually don' t sow it til Sept or so. It grows fast, is about 4 bucks for 50 lb, deer love it and it will grow just about grow on a rock. The farm stores haven' t even gotten it in yet this year. Was told today it would be near the end of the month. I use it to sow on my farm roads during winter to help
keep them from washing out and slipping.

Hope this helps,
Strutter