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Cornell University

Cover Crop Guide for NY Growers

Dr. Thomas Björkman, Horticulture Section, Cornell AgriTech

Mustard, Fall

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.

Land Preparation

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.

Seeding Rate

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.

Seed Cost

2007 price: $3.50/lb

Seeding Dates

Mid-July through August. Flowers in 4-6 weeks. See a tool to see the last planting date for your location (choose “mustard”).

Time Until Control

At flowering (4-6 weeks), or winter kill

Seed Suppliers

Rupp Seeds (Caliente 199), MinnDak Growers (Tilney), McKay Seeds (IdaGold, Pacific Gold).

Management Tricks

Do not let mustards go to seed.

Unavoidable Problems

Little spring residue.

Avoidable Problems

Harbor brassica diseases: do not use in rotations with brassica vegetable crops. Can suppress cucurbit crops that follow.

Classic Uses

After late-summer harvest, eg onions.




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.

All uses for Mustard, Fall
Management Goal Planting Time
Break Up Deep Compaction Late Summer
Increase Organic Matter Late Summer
Nitrogen Scavenging Late Summer
Reduce Weeds Late Summer
Stabilize Soil Aggregates Late Summer
Suppress Sclerotinia Late Summer
Suppress Verticillium Late Summer