Common, Alfalfa

Summer Alfalfa Seed

Fast-growing alfalfa builds substantial green manure biomass
Deep taproots help loosen compacted garden soils
Legume roots fix nitrogen for following crops
Purple flowers provide valuable forage for bees

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Key Attributes

Botanical Name

Medicago sativa

Days to maturity

60 Days

Sun

Full Sun

Zones 3–9 Check your growing zone

About Summer, Alfalfa Seed, Alfalfa Seed

The Common Alfalfa is a somewhat winter hardy perennial legume, but it grows more quickly than other regular alfalfa varieties. As an annual green manure, this cool-season "Summer" alfalfa can produce up to 10 tons of organic matter per acre. Its long taproots break up compacted soil and bring up subsurface minerals. High nitrogen fixation and great bee forage. Alfalfa is basically good at everything, as it great for nitrogen fixation and bee forage!

Growing details

Planting

Sow Depth

1/4"

Days to Germination

3–10 days

Row Spacing

Broadcast or Drill

Plant profile

Life Cycle

Perennial

Hardiness Zone

Zones 3-9

Plant Height

36 inches

Growth Habits

Upright

Seed & variety

Seeds Per Ounce

13,750

Seed Type

Open Pollinated

Before Planting

Obtain a soil test a season ahead: alfalfa needs deep drainage and a near-neutral pH. Eliminate perennial weeds, create a firm seedbed, and coat seed with the appropriate Sinorhizobium inoculant immediately before sowing.

Planting

Direct sow alfalfa in early spring as soon as a firm seedbed can be prepared, or in late summer where winters allow establishment. Broadcast or drill seed uniformly and ensure good seed-to-soil contact. Keep the surface evenly moist until seedlings establish, but avoid waterlogging. Do not thin a forage stand; manage density through the recommended seeding rate.

Watering

Moisture is most critical while the taproot develops and after each cutting. Apply enough water to wet the root zone, then allow aeration; prolonged saturation encourages Phytophthora and winter injury.

Fertilizer

Skip nitrogen when nodulation is healthy. Base lime, phosphorus, potassium, sulfur, and boron additions on soil and tissue tests, splitting potassium where leaching or heavy harvests make one large application inefficient.

Harvesting

For high-quality alfalfa forage, cut from late bud through early bloom; earlier cutting improves quality, while later cutting increases yield but coarsens stems. Leave sufficient stubble for regrowth and occasionally allow a longer recovery interval. For seed, wait until most pods are brown and dry.

Tips

Check roots six weeks after emergence for pink-centered nodules. Delay the first cut until crowns are established, and leave a late-season recovery period so plants rebuild carbohydrate reserves before freezing weather.

AVG. Seeding Rate

½ lb./1,000 sq.ft., 15–20 lb./acre. Use ½ this rate when sowing with a grain or grass.

Pests & Diseases

Anthracnose, Phytophthora root rot, bacterial wilt, and Fusarium or Verticillium wilts can thin stands. Look for straw-colored hooked stems, stunting, wilting, or discolored roots and crowns. Choose resistant varieties, plant in well-drained soil, rotate crops, control traffic when wet, and avoid moving contaminated soil or equipment.

Alfalfa weevils skeletonize spring terminals, potato leafhoppers cause yellow wedge-shaped “hopperburn,” and aphids cluster on shoots. Sweep or inspect plants before treating because beneficial insects often suppress aphids. Mow heavily damaged forage promptly, rotate stands, and use resistant varieties where leafhoppers recur.