Cover Crop Selection Guide for the Southeast

Cover crops are the cheapest fertilizer, weed control, and topsoil insurance you can buy. These six carry almost every Southeast vegetable rotation.

Cool-season

• Cereal rye. Sept 15–Nov 15 seeding at 90–120 lb/acre. Biomass king, best weed suppression. Terminate 3 weeks before cash crop plant.
• Crimson clover. Sept 15–Oct 30 at 20–25 lb/acre. Fixes 60–100 lb N/acre by full bloom in mid-April. Best pairing with rye at 60/20 lb ratio.
• Austrian winter pea. Sept 15–Oct 30 at 40–60 lb/acre. Fixes 50–90 lb N. Terminates cleanly, no residue issue for spring transplants.
• Mustard (Caliente 199). Sept 1–Oct 15 at 12–15 lb/acre. Biofumigant — plant before Solanaceae for soil-borne disease suppression.

Warm-season

• Cowpea (iron and clay). May 15–Aug 1 at 40–50 lb/acre. Fixes 40–70 lb N in 60 days. Fills gaps between brassica and fall cash crops.
• Sunn hemp. May 15–Aug 15 at 25–35 lb/acre. Grows 6 ft in 60 days, suppresses root-knot nematode. Best summer cover for coastal FL/GA.

Termination timing

Terminate legumes at 50–80% bloom for peak N release. Terminate rye before it exceeds 30 in — larger biomass ties up N and delays cash crop planting.

What to plant into next

Legume cover → heavy N feeder (tomato, pepper, corn). Rye cover → transplants only, not direct-seed small crops. Mustard cover → Solanaceae (that's the point).