How to Grow Alfalfa (Dormant Vernal WL 920)

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Alfalfa (Dormant Vernal WL 920)

Medicago sativa subsp. sativa

herb

Alfalfa is a deep-rooted, nitrogen-fixing perennial legume widely cultivated as a high-protein forage crop for livestock feed. Dormant Vernal WL 920 is a cold-hardy winter-dormant cultivar bred for northern climates, offering excellent winterhardiness and regrowth vigor after harvest. It produces nutritious forage with high digestibility and palatability for grazing or hay production.

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Example Alfalfa (Dormant Vernal WL 920) timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Alfalfa (Dormant Vernal WL 920)

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Alfalfa (Dormant Vernal WL 920)

    Around Aug 15

    ≈ 120 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Alfalfa (Dormant Vernal WL 920) dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 8+ hours daily; excellent light penetration promotes vigorous growth
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Water: Moderate to deep watering; alfalfa requires 15-20 inches annually. Drought-tolerant once established due to deep taproot (3-15 feet). Avoid waterlogging; ensure good drainage to prevent root rot and disease.
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Spacing: 6-12 inches between plants in rows; rows 24-36 inches apart for mechanized harvest inches
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Days to maturity: 120-150 days to first cutting; multiple harvests per season (3-5 in favorable climates)
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Planting depth: 0.25-0.5 inches; seed should be in firm contact with soil

Soil

Type: Well-draining loamy to clay-loam soil with good structure
pH: 6.5-7.5
Amendments:
Lime to raise pH if below 6.5 Phosphorus and potassium (conduct soil test) Boron (if deficient in soil test) Well-decomposed compost or manure for organic matter

Growing Zones

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Thrives in zones 2-8; Dormant Vernal WL 920 excels in zones 2-6 for northern production

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

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Growth Stages

1

Seedling

2-4 weeks

Cotyledons emerge and expand; first true leaves appear. Plant is tender and vulnerable to competition and drying.

Keep soil evenly moist but not waterlogged. Control weeds aggressively. Avoid grazing or harvest until plant has 3-4 true leaves and is 3-4 inches tall.

2

Vegetative Establishment

4-12 weeks (first season)

Plant develops multiple stems and expands leafy growth. Taproot penetrates deeply into soil. Plant builds energy reserves in root crown.

Light grazing or late-season cutting only in first year. Allow sufficient growth before dormancy. Maintain weed control. No nitrogen fertilizer needed (self-fixing).

3

Pre-Dormancy Hardening

4-8 weeks (late summer to fall)

As day length decreases in autumn, plant slows growth and moves carbohydrates into root crown. Foliage begins to harden; growth becomes more compact.

Cease grazing 6-8 weeks before hard freeze to allow carbohydrate accumulation for winter survival. Avoid harvest that removes too much foliage. This stage is critical for cold hardiness in Dormant Vernal cultivars.

4

Winter Dormancy

3-4 months (November-March in northern zones)

Above-ground growth stops completely; plant enters true dormancy. Below-ground crown and roots remain alive, protected by accumulated reserves.

No grazing or mechanical disturbance. Snow cover provides insulation. Dormant Vernal WL 920 is specifically bred to tolerate extreme cold in this phase.

5

Spring Regrowth & Production Years

Multiple cycles over 3-8 year stand life

Crown breaks dormancy as soil warms. Vigorous shoot growth emerges from crown buds. Multiple harvests possible per season once established (3-5 in north, up to 6 in south).

First cut at bud to early bloom stage (maximize quality and protein). Subsequent cuts every 28-35 days depending on growth rate. Always leave 3-4 inches of stubble for regrowth. Manage for pest/disease pressure.

Companion Planting

Plan your garden →

Plant with:

Grasses (orchardgrass, timothy, bromegrass) in mixed hay stands Chicory (in pasture mixes for livestock forage diversity) Birdsfoot trefoil (in cooler regions, adds palatability)

Avoid planting near:

Plants sensitive to root exudates or allelopathy (specific incompatibilities minimal) Stands with poor drainage or standing water (disease risk) Recent alfalfa fields (plant-back interval of 2-3 years recommended to reduce pest carryover)

Common Pests

  • Early cutting at bud stage removes weevil larvae; sweep nets for monitoring; biological control with parasitic wasps; insecticides if threshold exceeded (50% plants with 3+ larvae per stem)

  • Plant resistant varieties; maintain vigor with proper management; insecticidal soaps or oils; avoid excessive nitrogen fertilizer

  • Scout regularly; predatory insects (ladybugs, lacewings); timely harvest removes infested foliage; insecticides as last resort

  • Early cutting disrupts life cycle; monitor with sweep nets; predatory mites and insects; insecticides only if populations warrant

  • Regular scouting; early cutting; biological controls; avoid broad-spectrum insecticides that kill beneficials

  • Ensure excellent drainage; avoid waterlogging; use resistant varieties; rotate fields; avoid planting alfalfa-on-alfalfa within 2-3 years

  • Proper harvest management (avoid cutting too close); ensure good air circulation; remove infected plant material; Dormant Vernal WL 920 has good resistance

Uses

🍳

Livestock Forage & Feed

Culinary

Alfalfa is a premium forage crop for cattle, horses, sheep, and goats, providing excellent protein (15-22% dry matter) and balanced nutrition. Dormant Vernal WL 920 produces high-quality hay and pasture that supports milk production and animal health. [source]

💊

Nutritional Supplement & Phytochemicals

Medicinal

Alfalfa contains saponins, flavonoids, vitamins (K, A, B, C), minerals (calcium, phosphorus, magnesium), and amino acids used in herbal medicine traditions. Alfalfa sprouts are consumed fresh for their nutrient density and antioxidant properties. [source]

🏠

Soil Amendment & Nitrogen Fixation

Household

As a nitrogen-fixing legume, alfalfa enriches soil with bioavailable nitrogen through symbiotic relationships with Rhizobium bacteria. Incorporation of alfalfa reduces need for synthetic fertilizers in rotation systems. [source]

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Pollinator & Wildlife Habitat

Wildlife

Alfalfa flowers attract bees, butterflies, and beneficial insects, supporting pollinator populations. Alfalfa stands provide food and cover for birds and small mammals in agricultural landscapes. [source]

🎨

Industrial & Biofuel Applications

Craft

Alfalfa is used for animal bedding, mulch, biofuel feedstock, and as a green manure crop. Dormant Vernal WL 920's robust biomass production makes it valuable for multiple agricultural and industrial uses. [source]

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

Harvest Tips

First-year: Light grazing or late-season cutting only after 60+ days of growth. Subsequent years: Harvest at bud to early bloom stage for optimal nutritive value (protein and digestibility highest). Cut to 3-4 inches stubble height. In northern zones, cease harvest 6-8 weeks before first hard freeze to allow carbohydrate replenishment. Dormant Vernal WL 920 typically yields 3-5 cuts per season in zones 2-6. For hay, cut when plants in early bloom and dry to 15-20% moisture before baling.

Fun Facts

  • 🌱 Alfalfa's taproot can penetrate 3-15 feet into the soil, accessing water and nutrients unavailable to shallow-rooted crops, making it exceptionally drought-tolerant once established and useful for breaking up compacted subsoils.
  • 🌱 Dormant Vernal WL 920 was specifically bred for northern climates and exhibits 'true dormancy'—it enters a predictable winter rest that improves survival in zones 2-3, unlike non-dormant cultivars that may emerge from dormancy during warm spells and suffer freeze damage.
  • 🌱 A single alfalfa plant can produce thousands of seed in its lifetime, and the crop has been cultivated for over 2,000 years, originating in Central Asia and becoming one of the most important forage crops globally.

Gardening Terms

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