Sunn Hemp, Legumes

Common Sunn Hemp Seed

Fast-growing summer legume builds substantial soil-improving biomass
Roots fix nitrogen and help suppress plant-parasitic nematodes
Terminate near first flowering before stems become fibrous
Plant at least eight weeks before expected frost

See product details

Key Attributes

Botanical Name

Crotalaria juncea

Days to maturity

75 Days

Sun

Full Sun

About Common, Sunn Hemp Seed, Sunn Hemp Seed

The Sunn Hemp is a legume that makes an excellent cover crop as it is great for nitrogen fixation and nematode resistance in the soil. This legume is a fast-growing legume that produces significant quantities of biomass and fixes nitrogen into the soil with a short rotation of 60 days under optimum conditions. Plant the Sunn Hemp at least 8 weeks before first frost. For maximum benefit terminate crop at first flowering, prior to developing fibrous, hard-to-manage stalks. This legume is tolerant of dry conditions.

Growing details

Planting

Sow Depth

Days to Germination

3–10 days

Row Spacing

Broadcast or Drill

Plant profile

Life Cycle

Annual

Growth Habits

Upright

Seed & variety

Seeds Per Ounce

938

Seed Type

Open Pollinated

Before Planting

Sunn Hemp benefits from an open, sunny site with a firm, well-drained seedbed. Test the soil, correct pH and phosphorus or potassium deficiencies before planting, and control established weeds without overworking the surface. Inoculate sunn hemp seed with the correct fresh rhizobium strain when the crop or compatible legumes have not recently grown there.

Planting

Sunn Hemp is best direct-sown during its recommended seasonal window, when enough growing time remains for establishment. Broadcast or drill seed evenly, then roll or press the area to ensure firm seed-to-soil contact. Keep the surface moist until seedlings establish if rainfall is insufficient. These crops normally form a stand and are not thinned; use the separate seeding-rate guidance to control density.

Watering

Maintain moisture until sunn hemp forms a uniform stand. Established plantings usually need supplemental water only during extended dry periods; apply deeply and infrequently rather than keeping the surface constantly wet.

Fertilizer

Avoid routine nitrogen fertilizer on sunn hemp; healthy nodules normally supply the crop’s needs. Correct phosphorus, potassium, or pH deficiencies only as indicated by a soil test.

Harvesting

Sunn Hemp readiness depends on use: graze or cut while vegetative for quality forage, mow at early bloom for biomass, or allow seed to harden only when deliberate reseeding is desired.

Tips

Keep sunn hemp weed-free during establishment, then mow or terminate it before stems become woody and before viable seed develops. Allow enough residue-management time before the next crop.

AVG. Seeding Rate

1 lb./1,000 sq.ft., 30–50 lb./acre alone or ¼ lb./1,000 sq.ft., 4–8 lb./acre in a mix.

Pests & Diseases

Sunn hemp can develop Fusarium wilt, anthracnose, leaf spots, root rots, and viruses. Plant clean seed, rotate legumes, and avoid poorly drained fields. Remove stunted or mosaic plants before flowering. Do not retain seed from wilted stands or pods showing lesions and mold.

Watch sunn hemp for aphids, weevils, beetles, cutworms, and mites. Remove egg clusters and badly infested foliage, protect seedlings with collars, and avoid unnecessary broad-spectrum insecticides.