How to Grow Alfalfa, Vernal variety

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Alfalfa, Vernal variety

Medicago sativa subsp. sativa 'Vernal'

herb

Vernal alfalfa is a cold-hardy, dormant-type perennial legume widely used as a forage crop for livestock. It develops deep taproots and nitrogen-fixing nodules, making it valuable for pasture, hay, and soil improvement. Vernal is specifically bred for superior winter survival in northern climates.

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Example Alfalfa, Vernal variety timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Alfalfa, Vernal variety

    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, Vernal variety

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Alfalfa, Vernal variety dates for your own zip code.

Growing Conditions

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Sun: Full sun, minimum 6-8 hours daily; performs best with 8+ hours
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Water: Moderate; drought-tolerant once established due to deep taproot. Requires consistent moisture during establishment (first 6-8 weeks). In mature stands, natural rainfall of 15-20 inches annually is adequate; supplement during dry periods.
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Spacing: 6-12 inches between plants (direct seeding at 15-20 lbs/acre) inches
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Days to maturity: 60-90 days for first cutting; full productivity in year 2
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Planting depth: 0.25-0.5 inches for seeds; keep moist for germination

Soil

Type: Well-draining loamy to sandy loam soil with good structure
pH: 6.0-7.5
Amendments:
Lime (if pH below 6.0) Phosphorus and potassium fertilizer Compost for organic matter Boron and molybdenum (micronutrients)

Growing Zones

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Thrives in zones 2-8, with exceptional cold hardiness in northern regions (zones 2-4)

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

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Growth Stages

1

Seedling

2-3 weeks

Small cotyledons and first true leaves emerge. Plant is 1-2 inches tall, fragile, and susceptible to competition and damage.

Keep soil consistently moist but not waterlogged. Avoid grazing or cutting. Control weeds aggressively. Thin to desired spacing if direct seeded. Inoculate seeds with Rhizobium meliloti for nitrogen fixation.

2

Establishment

4-8 weeks

Root system deepens; plant reaches 6-12 inches with multiple stem branches. Taproot extends several inches into soil. Nodules form on roots.

Continue weed control. Water during dry periods to encourage deep rooting. Do not graze or cut during this critical period. Allow plant to build energy reserves.

3

Vegetative Growth

4-6 weeks per cycle

Plant is 12-24 inches tall, developing numerous leafy stems. Dense canopy forms with compound leaves. Root system is well-established; nitrogen fixation is active.

Harvest when plants reach bud to early bloom stage for best quality. Remove no more than 1/3 of growth in first year. Allow adequate regrowth between cuts (30-35 days). Monitor for pests.

4

Flowering and Seed Production

2-3 weeks per cutting

Purple, violet, or blue-violet flowers appear in dense clusters along stems. Plant reaches 24-36 inches. Flowers progress to seed pods.

For forage use, harvest before or at early flower stage for maximum nutrition. For seed production, allow flowers to mature fully. Support pollinators. Can be left for late-season grazing.

5

Dormancy and Winter Survival

November-March (zone dependent)

In fall, Vernal variety enters dormancy with reduced growth. Plants retain basal buds at soil surface. Minimal above-ground growth through winter.

Vernal's dormancy is key to winter survival in cold zones. Do not graze heavily in fall; leave 2-3 inches of stubble to insulate crowns. Provide well-drained conditions to prevent frost heave damage.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Oats Wheat Barley Flax Other legumes in the first year (competition)

Common Pests

  • Early cutting before larvae mature; insecticidal sprays if severe; beneficial parasitic wasps provide biological control

  • Cutting or grazing to reduce populations; tolerant varieties like Vernal; insecticides for severe infestations

  • Cutting before population buildup; insecticides if populations exceed thresholds

  • Early harvest; Bt (Bacillus thuringiensis) applications; natural predators

  • No significant management needed; damage is usually cosmetic

Uses

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Livestock Forage & Hay

Culinary

Vernal alfalfa is a premium forage crop with high protein content (15-20%) and excellent digestibility. It serves as a primary hay and pasture source for dairy cattle, beef cattle, horses, and other livestock, supporting productive animal agriculture. [source]

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Nutritional Supplement

Medicinal

Alfalfa leaf is used in herbal medicine and supplements for its high vitamin and mineral content, including vitamins A, D, E, K, and B vitamins. It is traditionally used to support digestive health and general wellness. [source]

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Soil Nitrogen Fixation

Household

As a nitrogen-fixing legume, alfalfa enriches soil through its symbiotic relationship with Rhizobium bacteria. It is commonly used in crop rotations and cover crop systems to reduce synthetic nitrogen fertilizer needs. [source]

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Erosion Control and Pasture Improvement

Household

Alfalfa's deep taproots help prevent soil erosion and improve soil structure. Its perennial nature and dense growth make it ideal for stabilizing pastures and reclaiming degraded land. [source]

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Pollinator and Wildlife Habitat

Wildlife

Alfalfa flowers are excellent nectar and pollen sources for honeybees, native bees, and butterflies. Flowering alfalfa fields provide important habitat and nutrition for pollinators and beneficial insects. [source]

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

Harvest Tips

Cut when plants reach bud to early bloom stage for best forage quality and protein content. First year: allow only 1-2 light cuttings. Year 2+: typically 3-4 cuttings per season in northern climates, more in southern zones. Leave 2-3 inches of stubble for regrowth. For hay: cut in morning after dew dries but before heat stress; allow 7-10 days to dry before baling. For grazing: rotationally graze; avoid overgrazing to maintain stand health.

Fun Facts

  • 🌱 Vernal alfalfa was developed at the University of Wisconsin and released in 1952 specifically for superior winter hardiness in cold climates; its dormancy trait is rare among alfalfa varieties.
  • 🌱 Alfalfa's taproot can extend 20-30 feet deep into the soil, allowing it to access water and nutrients far below the reach of most other crops—a key reason for its drought tolerance and longevity.
  • 🌱 One acre of alfalfa can fix 100-300 pounds of atmospheric nitrogen per year through its symbiotic partnership with Rhizobium bacteria, reducing the need for synthetic fertilizers and improving soil health.

Gardening Terms

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