In the Northeast, mustard is used as a fall-planted cover crop that winter-kills. This crop thrives in the cool conditions of fall and can give 100% ground cover. It adds organic matter, breaks up hardpan, and suppresses weeds in the following crop. Soil-borne diseases may be suppressed by glucosinolates in the residue. There are three species of mustard that behave similarly when sown in the fall.
Prepare a firm, weed-free seedbed to ensure a good stand. Available nitrogen levels at 120 lb N/ac. May require sulfur application at 6:1 N:S. Vegetable land often has sufficient nutrients.
Drill 5-12 lb/ac, depending on seed size.
Broadcast 10-15 lb/ac. Cover 1/2 inch.
After seeding, roll the ground to improve seed-to-soil contact but do not break up soil aggregates.
Mid-July through August. Flowers in 4-6 weeks.
Rupp Seeds (Caliente 199), MinnDak Growers (Tilney), McKay Seeds (IdaGold, Pacific Gold).
Winter-kill followed by incorporation in the spring. Do not let mustards go to seed.
Do not use in rotations with other Brassicas.
Early planting the following spring is possible because fall mustards leave little spring residue.
Use for disease control after onions and lettuce on the muck. Use to suppress Verticillium in potato and to reduce weeds in the following crop.
Mustards attract flea beetles and diamond-back moths, but the risk is lowest in the fall.
Fall mustards are also discussed in the article on Early fall cover crops.