FWIW, I am not a glyphosate fan. Since you already killed the grass, I would frost seed an annual clover before spring green up. After frost threat has passed in the spring, I would mow the clover to "set it back" and then broadcast buckwheat. Maybe the clover and buckwheat will set seed. In August, I would seed a perennial clover, rye cereal grain and radish. I am not a monoculture guy. You will get plenty of advice and information on this site.
Frost seed Balansa Fixation clover 5-8 lbs/acre
Post frost Buckwheat 40–90 lbs./ac
Fall planting Rye 50 lbs,/ acre
Ladino clover 3 lbs. / acre
Forage radish 3 lbs / acre
Additional info: I had frost in June. Followed by drought and stunted growth. Fall is great time to establish perennials. There is much information on this site. Good luck.