Green Grass Grove
Connecting specimen records, habitat data, and the living archive.
Sunn Hemp
Crotalaria juncea L.Sunn hemp is a rapid tropical legume cover crop for biomass, nitrogen contribution, weed suppression, and selected nematode programs, with mandatory seed and toxicity controls.
Botanical Overview
Sunn hemp is a rapid tropical legume cover crop for biomass, nitrogen contribution, weed suppression, and selected nematode programs, with mandatory seed and toxicity controls.
Why We Feature This Specimen
A living field record of Sunn Hemp lets Green Grass Grove connect seed stewardship, soil cover, food production, wildlife interactions, and seasonal climate observations in one traceable specimen profile.
Climate & Protection
Sun / Light: Full sun.
Strongly heat tolerant and frost tender. Growth slows as days shorten and cold arrives.
Heat-zone and verification notes
Not assigned; use crop-stage and seasonal guidance.
Planting & Seasonal Guide
Starting & Germination Methods
Seed Sowing
Seed sowing is the umbrella operational method for placing botanical seed into a germination environment. It includes selection of containers or beds, medium, depth, spacing, moisture, temperature, light,…
Open Full Method ↗Direct Sowing
Direct sowing is the establishment of plants by sowing seed outdoors or into the final production bed rather than transplanting nursery-grown seedlings. It is a complete site operation…
Open Full Method ↗Direct Seed
Direct Seed is retained as a legacy identity for placing seed directly into its final production container, bed, plug position, restoration cell, or growing location without first raising…
Open Full Method ↗Plant after frost danger into warm soil. In Live Oak, terminate before stems become woody, seed matures, or tropical-storm lodging makes management difficult.
Plant in North Florida during warm frost-free weather and schedule mowing or incorporation before viable seed production.
Spacing: Use the verified seeding rate for cover-crop goals; dense stands maximize biomass and weed suppression.
Planting Depth: Direct sow about 1/2–1 inch deep.
Pollination: Wind pollinated and isolation-sensitive for corn and cereals; insect-assisted or self-pollinated according to crop. Preserve seed only from identified, healthy, adequately isolated plants.
Water, Soil & Nutrition
💧 Water & Moisture
Provide moisture for germination and establishment; mature stands tolerate short dry periods but not waterlogging.
Even establishment moisture with aerated roots; crop-specific drought tolerance develops only after rooting.
Generally adapted to humid summers, though dense mature stands can lodge and retain moisture. Scout for stem and root disease after extended saturation.
↘ Drainage & Root-Zone Behavior
✦ Nutrition & Deficiency Checks
As a legume, sunn hemp can fix nitrogen when nodulated. Avoid unnecessary nitrogen and base phosphorus, potassium, and pH correction on soil tests.
Poor nodulation may reflect missing compatible rhizobia, low pH, waterlogging, or nutrient imbalance. Yellowing should be diagnosed before nitrogen is applied.
Growth, Maintenance & Harvest
Maintenance & Pruning
Remove damaged or diseased tissue only when practical. Cover crops are managed mainly by mowing, crimping, cutting, or timely termination rather than ornamental pruning.
Harvest or Observation
This Profile supports cover-crop biomass and seed for controlled propagation, not food or unsupervised livestock feed.
Storage & Preservation
For cover-crop use, mow, crimp, or incorporate before thick woody stems and mature seed develop. This is not a normal edible harvest profile.
Harvestable Plant Parts & Uses
For cover-crop use, mow, crimp, or incorporate before thick woody stems and mature seed develop. This is not a normal edible harvest profile.
Propagation, Cloning & Tissue Culture
Propagation Methods
Seed
Seed is retained as an umbrella propagation identity for sexual reproduction through mature botanical seed. A seed normally contains an embryo, stored reserves or nutritive tissue, and protective…
Open Full Method ↗Direct Seed
Direct Seed is retained as a legacy identity for placing seed directly into its final production container, bed, plug position, restoration cell, or growing location without first raising…
Open Full Method ↗Aquaponics, Hydroponics & Aeroponics
Aquaponics
Not recommended as a routine aquaponic crop because space, duration, anchorage, or harvest method conflicts with the system.
Hydroponics
Not recommended as a routine hydroponic crop; field or raised-bed culture is more operationally appropriate.
Aeroponics
No profile-specific operating notes have been recorded.
Pests, Diseases, Safety & Toxicology
Root-knot nematode response varies by nematode population; other risks include caterpillars, beetles, aphids, and pod-feeding insects.
Seedling rots, root rots, leaf spots, and wilt diseases may occur under poor drainage or contaminated seed.
Use certified seed, inoculate where appropriate, verify the target nematode species, mow or incorporate before seed set, and account for residue before planting the next crop.
Late termination, woody residue, lodging, volunteer seed, root-knot nematode race differences, and livestock toxicity concerns.
Seeds and some plant tissues contain toxic pyrrolizidine alkaloids and are not human food. Livestock use requires specific agronomic and veterinary guidance.
Prevent seed access by children and livestock, terminate before seed maturity, wear protection during dusty mowing, and label residue-management trials clearly.