Late summer can be an excellent time to establish alfalfa for productive stands next spring. These key recommendations will help you successfully establish alfalfa in late summer.
- Plant six weeks before first killing frost. Alfalfa needs 45 days’ growth from germination to the first killing frost to survive the winter.
- Eliminate weed competition. Use a burndown herbicide like glyphosate to control perennial weeds and volunteer small grains prior to planting.
- Lime and fertilize. Before summer planting, have your soil tested, and follow lime and fertilizer recommendations for phosphorus, potassium and sulfur.
- Direct seed alfalfa for best success.Companion crops compete for sunlight and moisture. If a companion crop is needed to prevent erosion, control oats by planting at one-half bushel per acre.
- Plant when soil conditions are right. Avoid planting alfalfa into extremely dry soil with little chance of rain in the near-term forecast.
- Monitor seeding depth. Ideal planting depth for alfalfa in clay or loam soils is one-quarter to one-half inch. For light or sandy soils, seeds should be placed at one-half to three-quarters inch deep.
- Plant winter-hardy, disease-resistant varieties.Seedling diseases are not as important in the late summer seeding as in spring seeding, but major diseases and winter-hardiness are still key factors for persistence.
- Maintain normal seeding rates. Plant alfalfa at 15 to 18 pounds per acre to ensure an adequate stand.
- Don’t reseed into old alfalfa stands. Alfalfa plants produce a toxin that can reduce root development and survival of new seedlings. You can reseed immediately into a failed spring seeding (or one from the previous fall), but if an alfalfa stand is more than a year old, don’t attempt to reseed for at least one year.
While late-summer seedings present some risks, they offer many advantages for establishing strong, productive alfalfa stands on your farm.