How to Grow Alfalfa 'Vernal Magnum'

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Alfalfa 'Vernal Magnum'

Medicago sativa var. Vernal Magnum

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Vernal Magnum is a cold-hardy perennial legume cultivar bred for superior forage production and winter survival in northern climates. It features excellent disease resistance and yields substantial biomass for hay, pasture, and animal feed. This variety is specifically selected for its combination of yield potential and winterhardiness.

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

Plant Alfalfa 'Vernal Magnum'
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Alfalfa 'Vernal Magnum'
Around Aug 15

≈ 120 days after planting

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

Growing Conditions

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Sun: Full sun, 6+ hours daily

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Water: Moderate; establishes deep taproot reducing drought sensitivity once mature. Requires adequate moisture during establishment (first 6-8 weeks). Tolerates occasional drought after establishment.

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Spacing: 4-6 inches between plants in row; rows 12-18 inches apart for field cultivation inches

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Days to maturity: 120-150 days for full establishment; harvesting begins 60-90 days after planting

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Planting depth: 0.25-0.5 inches; shallow planting ensures good seed-soil contact

Soil

Type: Well-draining loamy soil with moderate fertility

pH: 6.5-7.5

Amendments:

Lime if pH below 6.5 Phosphorus Potassium Inoculant containing Sinorhizobium meliloti (alfalfa bacteria)

Growing Zones

Find your zone →

Best suited to zones 2-7; excellent cold hardiness makes it ideal for northern regions

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

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Growth Stages

Germination & Seedling

10-14 days

Fine cotyledons emerge, growth is rapid with first true leaves appearing. Seedlings are delicate and vulnerable.

Keep soil consistently moist but not waterlogged. Protect from foot traffic and grazing. Avoid herbicides at this stage.

Vegetative Establishment

4-8 weeks

Multiple stems develop from the crown. Plant builds foliage and develops the characteristic compound leaves. Root system deepens.

Light grazing or cutting may be done cautiously; avoid heavy defoliation. Ensure consistent moisture. Monitor for pests.

Pre-Flowering/Bud Stage

2-4 weeks

Plant reaches 12-18 inches tall with abundant stems and dense foliage. Flower buds begin to form at stem tips.

This is the optimal harvest stage for quality forage. Cut before flowers fully open to maximize nutritive value and stem tenderness.

Flowering

2-3 weeks

Purple-blue flowers bloom along stems. Plant height increases, stem quality declines, and fiber content rises.

Harvest immediately if forage quality is priority. Allow some flowers if seed production is desired (extends harvest window).

Regrowth/Dormancy

4-8 weeks per regrowth cycle

After cutting, plant rapidly regenerates multiple new shoots from the crown. Fall regrowth prepares plant for winter dormancy.

Allow adequate regrowth (8-12 inches) before winter to build root reserves. In northern zones, stop harvesting 6 weeks before first frost.

Companion Planting

Plan your garden →

Plant with:

Orchardgrass Timothy grass Bromegrass Birdsfoot trefoil Other cool-season grasses for mixed pasture

Avoid planting near:

Sainfoin (competes for nitrogen fixation) Other nitrogen-fixing legumes in pure stands (unless managed blend) Recently treated herbicide fields (residues may inhibit alfalfa)

Common Pests

Scout for larvae in spring; early harvest removes weevils; resistant varieties help; insecticides as last resort
Monitor populations; early cutting removes infested foliage; predatory insects; avoid broad-spectrum insecticides
Plant resistant varieties; early harvest; apply insecticides only if population exceeds economic threshold
Early harvest removes nymphs; maintain plant vigor; biological controls (parasitic wasps)
Monitor for population buildup; early mowing can prevent damage; insecticides only for severe infestations

Uses

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Livestock Feed & Hay Production

Culinary

Vernal Magnum is grown primarily as a high-protein forage crop for cattle, horses, sheep, and other livestock. Its excellent nutritional profile and digestibility make it a premium hay and pasture source. [source]

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Human Nutritional Supplement

Medicinal

Alfalfa sprouts and leaf powder are consumed by humans as nutritional supplements rich in vitamins, minerals, and antioxidants. Traditionally used to support digestive health and overall wellness. [source]

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Soil Improvement & Nitrogen Fixation

Household

As a nitrogen-fixing legume, alfalfa builds soil fertility through symbiotic relationships with rhizobial bacteria, reducing the need for synthetic nitrogen fertilizers and improving soil structure. [source]

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Pollinator & Wildlife Habitat

Wildlife

Alfalfa flowers provide excellent nectar and pollen for honeybees and native pollinators. The dense foliage also offers shelter and food for beneficial insects and small wildlife. [source]

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Agricultural Research & Breeding

Craft

Vernal Magnum represents decades of plant breeding for cold hardiness and disease resistance, making it valuable for agricultural science and sustainable farming practices. [source]

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

Harvest Tips

Harvest at bud stage (early flowering) for maximum nutritive value and palatability. For forage: cut when 10-15% flowers are open. Multiple harvests per season possible (2-4 cuttings depending on region and moisture). In northern zones, stop harvesting 6 weeks before expected first frost to allow winter hardening. For seed production, allow plants to mature fully and dry down before combine harvesting.

Fun Facts

🌱 Alfalfa has a deep taproot that can extend 12-20 feet into the soil, making it extremely drought-tolerant once established and able to access water unavailable to shallow-rooted plants.
🌱 The name 'alfalfa' comes from Arabic 'al-fal-fa' meaning 'father of all foods'—it was valued by Persian and Arab horse breeders centuries ago for its nutritional density.
🌱 Vernal Magnum was developed specifically for Canadian and northern U.S. climates and has superior winterhardiness compared to common alfalfa varieties, surviving temperatures well below -30°F.

Gardening Terms

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

Crown Cultivar Full Sun Perennial True Leaves

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