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Cornell University

Cover Crop Guide for NY Growers

Dr. Thomas Björkman, Horticulture Section, Cornell AgriTech

Forage Turnip and Rapeseed

Fall-seeded Brassicas, turnips and rapeseed, offer weed suppression in the following crop and decompose quickly after being terminated. Turnip and rapeseed fast in the fall and are good at reducing surface compaction while providing winter cover and fall weed suppression.

Land Preparation

Smooth, weed-free seedbed, well-drained with enough moisture.

Seeding Rate


Drill 4-7 lb/ac, 1/2 inch deep. Broadcast 10-12 lb/ac on firm seedbed, cover 1/2 – 3/4 inches. Use the higher rate if fall weed suppression is the goal.


Drill 5-10 lb/ac, less than 3/4 inches deep. Broadcast 8-14 lb/ac. Cover up to 1 inch. Seed can be no-tilled into suppressed sod or seeded into a conventionally prepared seedbed. Till as necessary to kill the first flush of weeds to ensure a weed free seedbed. After seeding, roll the ground to improve seed-to-soil contact but do not break up soil aggregates.

Seed Cost

2007 price: $2.00-$5.00/lb

Seeding Dates

August.  See a tool to find the last date for your specific location. (Chose “Mustard.”)

Time Until Control

Frost kill

Seed Suppliers

Ernst Conservation Seed, AMPAC Seed Company. Appin turnip winterkills reliably if sown by August 25. Pasja and Bonar rapeseed may have incomplete winter kill and require control in the spring.

Management Tricks

Roll or drag the ground after planting to ensure good seed-to-soil contact.

Unavoidable Problems

Harbor brassica diseases: do not use in rotations with brassicas.

Avoidable Problems

Slow to establish, prepare a smooth, weed free seed bed. May suppress cucurbit crops that follow.

Classic Uses

Break up compaction, low residue in spring.


Avoid wet spots.


Incorporate in spring, any time before full flowering.


These cover crops can harbor Brassica disease; do not use in rotation with Brassicas. Useful for suppressing Sclerotinia in lettuce.

All uses for Forage Turnip and Rapeseed
Management Goal Planting Time
Nitrogen Scavenging Late Summer
Reduce Surface Hardness Late Summer
Reduce Weeds Late Summer
Winter Erosion Protection Late Summer