Cover Crops for Vegetable Growers
Newsletter articles
Early summer
Mid and
late summer
Late summer
legumes
Early fall
Fall
Early spring
Cover crop information
Buckwheat
Annual
ryegrass
Oats
Wheat (includes
spelt, triticale)
Rye
Sudangrass
Reed Canarygrass
Arugula
Mustard, spring
Mustard, fall
Forage
Radish
Forage Turnips
Red
clover
Hairy Vetch
Field Peas
White
Clover
Sudangrass and SorghumXSudangrass Click to download printable PDF file
Sudangrass and Sorghum-Sudangrass are midsummer grasses suitable for short, 8 to 10 week plantings. Sorghum-sudangrass if often referred to generically as Sudex, although that is DeKalb’s trademarked name. These grasses are the most heat and drought tolerant cover crops typically grown in the Northeast. Sudangrass growth is easier to manage because the stems are narrower , it can be sown earlier than sorghum-sudangrass, and suppresses weeds better. These crops provide abundant root biomass, which is useful for increasing soil organic matter. Mowing encourages root growth. They suppress root knot nematodes, and weed germination if densely sown.Land
Preparation
Prepare a clod free seedbed. Avoid hard soil and wet spots. Do not
plant just before a heavy rain.
Seeding
date
June through mid-August (sudangrass)
July through mid August. (sorghum-sudangrass)
These cover crops require warm soil to germinate.
Seeding
Rates
30 lb/ac for biomass and nematode control
50 lb/ac for weed control.
Seed size varies, so if using a variety with larger or smaller seed
size than average, adjust the rate to provide a similar plant
population.
Seed
sources
Albert Lea Seedhouse, Seedway, UAP, local farm seed dealers.
To suppress nematodes, use a variety that is high in dhurrin such as Trudan8, Sordan 79, Green Grazer and Special effort. See the section on root knot nematode.
Maintenance
Mow when 20 to 30 inches tall, leaving 6 inch stubble . Leave residue
on the soil surface for weed suppression. Timely mowing is important
because tall fibrous plants are difficult to mow or incorporate.
Control
Big crowns decompose slowly, making it difficult to prepare a seedbed
for small-seeded crops. Incorporate sudangrass if planting
something else in the fall. Otherwise, mow for winter-killed mulch on
the surface and till in early spring.
Tips
Good summer cover if a long mid-summer period is available. Usually
followed by a winter grain cover crop. For shorter summer
opportunities, use buckwheat. This plant can be used in some insectary
mixes because Sorghum may harbor greenbug (Schizaphis graminum),
which
in turn attracts lady beetles, lacewings, and other beneficial
predatory insects.
