Sun Hemp

Herbaceous

Sun Hemp

Crotalaria juncea

Also known as: Brown Hemp, Indian Hemp, Madras Hemp

Herbaceous Fabaceae Nitrogen FixerMulcherDynamic AccumulatorErosion ControlBiofuel
Hardiness Zone
8-12
Ideal Temp
70–90°F
Survives Down To
40°F
Life Cycle
Annual

Sun Hemp (*Crotalaria juncea*) is a fast-growing annual legume primarily cultivated as a cover crop and green manure. It grows upright, reaching heights of 1 to 3.5 meters (3 to 11.5 feet) with fibrous, ridged stems. The leaves are oblong-lanceolate, spirally arranged along the stem, measuring 4 to 12 centimeters (1.5 to 4.7 inches) in length. It produces bright yellow, pea-like flowers in terminal clusters, followed by small seed pods containing black or brown seeds. Its deep taproot improves soil aeration while fixing nitrogen into the soil. ✂️🫘 Methods to Propagate: Sun Hemp is best propagated through direct seeding. Seeds should be sown at a depth of 1.5 to 2.5 centimeters (0.6 to 1 inch) in warm, well-drained soil when temperatures exceed 20°C (68°F). Germination occurs within 3 to 7 days. 🌞💧 Sun and Water Requirements: This plant thrives in full sun and prefers well-drained sandy or loamy soils with a neutral to slightly acidic pH. It is drought-tolerant but benefits from occasional watering in dry conditions. 🧑‍🌾👩‍🌾 When to Harvest: If used as green manure, Sun Hemp should be incorporated into the soil before flowering (around 8 to 12 weeks after planting). For fiber production, it should be harvested at full bloom when stems are at their strongest.

Good Neighbors
  • Corn
  • Sorghum
  • Millet
  • Cowpea
Cautions
  • None known
Known Threats — Organic Solutions Only
Aphids
Aphidoidea
Banded Cucumber Beetle
Diabrotica balteata
Bean Aphid
Aphis fabae
Bean Leaf Beetle
Cerotoma trifurcata
Bean Weevil
Acanthoscelides obtectus
Borers
Various (e.g., Cerambycidae, Sesiidae)
Brown Marmorated Stink Bug
Halyomorpha halys
Corn Earworm
Helicoverpa zea
Cowpea Curculio
Chalcodermus aeneus
Fall Armyworm
Spodoptera frugiperda
Fusarium Wilt
Fusarium oxysporum
Ganoderma Butt Rot
Ganoderma spp.
Harlequin Ladybird
Harmonia axyridis
Kudzu Bug
Megacopta cribraria
Locust Borer
Megacyllene robiniae
Locust Leaf Miner
Odontota dorsalis
Lubber Grasshopper
Romalea microptera
Pea Moth
Cydia nigricana
Pea Weevil
Bruchus pisorum
Pythium Root Rot
Pythium spp.
Reniform Nematode
Rotylenchulus reniformis
Root Aphid
Pemphigus spp.
Rootknot Nematodes
Meloidogyne spp.
Soybean Looper
Chrysodeixis includens
Spittlebugs
Cercopidae
Spotted Cucumber Beetle
Diabrotica undecimpunctata howardi
Stink Bug
Pentatomidae
Striped Cucumber Beetle
Acalymma vittatum
Velvetbean Caterpillar
Anticarsia gemmatalis
White Rot
Sclerotinia sclerotiorum