How to Grow Legumes (Clover, Vetch, Alfalfa)

Wikimedia Commons

Legumes (Clover, Vetch, Alfalfa)

Trifolium spp., Vicia spp., Medicago sativa

legume cover crop

Legumes are nitrogen-fixing plants that form symbiotic relationships with Rhizobium bacteria in root nodules, enriching soil with bioavailable nitrogen. Commonly used in crop rotation and mixed plantings, they improve soil fertility, prevent erosion, and provide forage or green manure. These plants are essential to sustainable agriculture and regenerative farming practices.

When should you plant Legumes (Clover, Vetch, Alfalfa) in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Legumes (Clover, Vetch, Alfalfa) timeline →

Example Legumes (Clover, Vetch, Alfalfa) timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Legumes (Clover, Vetch, Alfalfa)

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Legumes (Clover, Vetch, Alfalfa)

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Legumes (Clover, Vetch, Alfalfa) dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; some varieties tolerate partial shade
💧
Water: Moderate to consistent moisture during establishment; once established, most legumes are drought-tolerant. Water deeply but infrequently; avoid waterlogging. Alfalfa requires good drainage and less frequent watering than clovers.
📏
Spacing: 4-8 inches apart (seed densities vary by species: clover 8-15 lbs/acre, vetch 40-60 lbs/acre, alfalfa 10-15 lbs/acre) inches
📅
Days to maturity: Clover: 60-90 days to first harvest; vetch: 90-120 days; alfalfa: 120-150 days to full establishment
🌱
Planting depth: 0.25-0.5 inches (shallow; keep seed in contact with soil)

Soil

Type: Well-draining loamy to clay loam soil; alfalfa prefers deeper, well-draining soil; clovers tolerate lighter soils
pH: 6.0-7.5
Amendments:
Inoculant with appropriate Rhizobium strain (essential if legume not grown recently) Phosphorus and potassium (boost nodulation) Lime (if pH below 6.0) Compost (improves soil structure)

Growing Zones

Find your zone →

Clover thrives in zones 3-9; vetch in zones 4-9; alfalfa in zones 3-10, with specific varieties for colder regions

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

Sign up free to see if Legumes (Clover, Vetch, Alfalfa) grows in your zone — and get a personalized planting timeline.

Get my Legumes (Clover, Vetch, Alfalfa) timeline →

Growth Stages

1

Germination & Seedling

2-3 weeks

Seeds sprout within 7-14 days. Cotyledons emerge; first true leaves appear. Plant is delicate and low to ground.

Keep soil consistently moist but not waterlogged. Ensure inoculant contact with seeds for nitrogen fixation. Protect from heavy foot traffic. Apply pre-emergent only if necessary—not recommended for legumes due to fungicide sensitivity.

2

Vegetative/Establishment

3-6 weeks

Rapid leaf and root development. Root nodules begin forming as Rhizobium bacteria colonize roots. Plant reaches 4-6 inches in height. Deep tap roots (especially alfalfa) developing.

Minimal fertilizer needed; nitrogen fixation will begin. Ensure consistent moisture. Mulch lightly to retain moisture and suppress weeds. Monitor for legume-specific pests (weevils, aphids). Do not overwater; promotes disease.

3

Growth & Development

6-10 weeks

Vigorous biomass accumulation. Nodules active and fixing nitrogen. Plant reaches 12-24 inches depending on species. Branching and spreading occurs in clovers; vetch becomes vinelike; alfalfa extends deep roots.

Allow natural growth; minimal intervention needed. Tolerate some weed competition but manage heavily competitive weeds. Remove any diseased foliage. Begin planning termination timing if using as cover crop.

4

Flowering & Seed Set

2-4 weeks (flowering); 2-3 weeks (seed maturation)

Characteristic flowers appear (white, red, pink, or purple depending on species). Small legume pods develop. Peak nitrogen fixation occurs.

Optimal time to terminate cover crop and incorporate into soil for green manure benefit. If harvesting for seed, allow pods to mature and dry. If harvesting for forage, cut at late bud to early flower stage for highest protein.

5

Mature/Senescence

2-4 weeks

Seed pods mature and dry down. Foliage may yellow and decline. Nitrogen content remains high in plant tissue. Seeds ready for collection if desired.

This is the standard termination window for cover crops. Mow, turn, or incorporate into soil 2-3 weeks before planting cash crop to allow decomposition. For persistent varieties (alfalfa), allow self-seeding or collect seed. Perennial clovers will regrow if not fully terminated.

Companion Planting

Plan your garden →

Plant with:

Grasses (in mixed pastures or cover crop blends) Oats (in cover crop mixtures) Rye (winter cover crop blend) Brassicas (following legume rotation) Corn (in rotation; legume fixes N for subsequent crop) Root vegetables (carrots, beets—following legume) Cucurbits (squash, pumpkin—benefit from legume nitrogen)

Avoid planting near:

Other legumes of same species (disease buildup, pest pressure) Legume-sensitive herbicides (glyphosate tolerated by most; some growth regulators inhibit nodulation) Heavy nitrogen fertilizer applications (suppress nodulation) Allelopathic plants (black walnut, eucalyptus) Recently lime-treated fields (wait 2-3 weeks for pH to stabilize)

Common Pests

  • Monitor for larvae in spring; early mowing disrupts life cycle; biological control with parasitoid wasps; resistant varieties available

  • Early cutting before peak larval emergence; insecticides if economic threshold exceeded; parasitoid wasps provide natural control

  • Tolerate low populations; predatory insects (ladybugs, lacewings) control naturally; insecticidal soap for heavy infestations; avoid broad-spectrum insecticides that kill beneficials

  • Improve air circulation and drainage; use resistant varieties; avoid overhead irrigation; sanitize equipment between fields

  • Plant resistant varieties; ensure good drainage; rotate away from legumes for 3-4 years; no fungicide cure once established

  • Use resistant varieties when available; some legume varieties suppress nematode populations; incorporate green manure to build soil health

Uses

🍳

Forage & Livestock Feed

Culinary

Legumes provide high-protein forage for cattle, sheep, goats, and other livestock. Alfalfa hay is a premium feed; clovers are excellent pasture species. Fresh or dried legumes have balanced amino acid profiles. [source]

🏠

Nitrogen Fixation & Soil Amendment

Household

Legume root nodules convert atmospheric nitrogen into plant-available form through Rhizobium symbiosis. Incorporation of legume biomass as green manure adds 100-300 lbs nitrogen/acre, eliminating need for synthetic nitrogen fertilizers in subsequent crops. [source]

💊

Traditional & Herbal Remedies

Medicinal

Red clover (Trifolium pratense) is used in herbal medicine for menopausal symptoms and respiratory support; alfalfa sprouts are nutrient-dense; contains isoflavones and other bioactive compounds. [source]

🏠

Erosion Control & Soil Structure

Household

Dense root systems prevent erosion on hillsides, reduce runoff, and improve soil structure. Extensive root nodule networks enhance soil aggregation and water infiltration, improving long-term soil health and carbon sequestration. [source]

🦋

Pollinator & Wildlife Habitat

Wildlife

Legume flowers are excellent nectar and pollen sources for bees, butterflies, and other pollinators. Legume-dominant pastures support diverse beneficial insect populations and provide habitat for ground-nesting birds. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

For cover crop/green manure: Terminate by mowing or cultivation 2-3 weeks before planting cash crop to allow decomposition and nitrogen release. For forage: Cut at late bud to early flower stage for highest protein content and palatability; allow 4-6 weeks regrowth between cuts. For seed: Allow pods to mature, dry fully on plant, then harvest via cutting, drying, and threshing. Perennial clovers and alfalfa can be harvested 2-4 times per season if managed for forage. Monitor nodules—active nodules appear pink/red inside, indicating active nitrogen fixation.

Fun Facts

  • 🌱 A single mature alfalfa plant can extend its tap root 15-20 feet deep, accessing water and nutrients far below the reach of other plants, making it exceptionally drought-tolerant once established.
  • 🌱 The nitrogen-fixing symbiosis between legumes and Rhizobium bacteria was not scientifically understood until the late 1800s; before then, farmers relied on centuries of empirical knowledge that rotating legumes restored soil fertility.
  • 🌱 Red clover can produce 100-200 lbs of nitrogen per acre per year through biological fixation—equivalent to 200-400 lbs of synthetic nitrogen fertilizer, making legume rotations a foundational practice in organic and regenerative agriculture.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Legumes (Clover, Vetch, Alfalfa) planting timeline

Tell us your zip code and we'll calculate exactly when to start Legumes (Clover, Vetch, Alfalfa) seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Legumes (Clover, Vetch, Alfalfa) timeline →