When a spring alfalfa seeding has failed due to wet soils, weather, disease problems or unexpected herbicide carryovers, or when an older stand is deemed unproductive, late summer planting allows a grower to establish alfalfa fields with a good chance for success, sometimes with better odds than spring seeding.
Factors to Consider
- Weed control
- Insect management
- Soil temperature and moisture
- Select a time to plant. Experts suggest seeding alfalfa about six to eight weeks prior to the killing frost for your area. Seeding too early can increase the risk for hot, dry conditions; seeding too late may not allow the alfalfa to develop enough to build food reserves to carry it through the winter.
In Wisconsin and Minnesota, seeding is recommended between Aug. 1 and Aug. 15. The earlier planting date is suggested for both northern Wisconsin and central Minnesota. Yearly conditions may vary, so slightly earlier or slightly later seeding dates can result in successful stand establishment.
- Prepare the seedbed. Agronomic practices used for spring seeding also apply to late-summer seeding. The field should have adequate fertility and necessary pH levels for alfalfa establishment. The seedbed needs to be appropriately firm and free of weeds. Seeding rates should be the same as for spring seeding. Twelve to 20 pounds per acre is the range of seeding rates used throughout alfalfa-growing areas. Seeding depth should be between ¼ inch and ½ inch.
- Harvest at the appropriate time. Fall harvest of late-summer-seeded alfalfa is not recommended because the root systems in these seedlings are not adequately developed to get the plant through winter after a fall harvest. However, next spring, a late-summer-seeded field can be handled like a spring-seeded field.
Late summer planted alfalfa is sometimes a good option for establishing an alfalfa field if spring seeding was not successful. Mycogen Seeds forage and alfalfa experts can provide specific recommendations regarding late summer planting of alfalfa. For more information, contact your local Mycogen Seeds customer agronomist or trusted agronomic adviser.