Summer Seeding Alfalfa

A Success Story

The wet conditions we had this spring to get crops planted have led to the need to summer seed alfalfa. Summer seeding alfalfa is a great alternative to spring seeding, and sometimes it comes with greater success. With warmer(and typically drier) soil temperatures, soilborne diseases that we see in the spring months are much less of a concern for summer-seeded alfalfa. Weed pressure is also less of a problem since most of the weed germination “flushes” have passed. Also, if you have any annual weeds, the first freeze will eliminate any of them that have germinated.

Timing

Summer seeding alfalfa needs time to establish before winter. In most of our sales region, planting between August 1-15 is recommended. Seeding too early increases the risk of hot and dry conditions to hinder seedling germination and development. Seeding too late doesn’t allow new seedlings enough time to develop enough root and top growth before winter.

Field Conditions and Planting

I would be distraught if I didn’t mention a few other important things about seeding alfalfa. First, we need to think about herbicide history on each field that is going to be seeded. Many common corn, soybean, and small-grain herbicides have planting restrictions for seeding alfalfa. Check out this tech sheet with common herbicides and their rotational restrictions for planting alfalfa. Remember to read and follow each product’s label. Second, soil pH needs to be addressed. A soil pH of around 6.8 is optimal for alfalfa and many other crops. A soil pH that is too low will result in poor stand establishment. Along with pH, soil fertility needs to be at optimum levels have a successful establishment. Lastly, and sometimes the biggest reason for stand establishment failures is seeding depth. Alfalfa needs to be seeded at ¼ to ½ of an inch. Firming the seedbed before planting is needed in many cases if the soil is too loose or fluffy(especially in sandy soils) due to tillage practices. Firming after planting is also critical to get good seed-to-soil contact and to keep moisture in the soil for germination.

Harvest

With summer-seeded alfalfa, it is never recommended to take a cutting during the fall of the establishment year. Although it may be tempting to take a cutting due to the exceptional amount of top growth, the roots need time to develop and store energy to go through that first winter.

As always, if you have questions about seeding alfalfa or any other crop, feel free to contact me or any other Legacy Seeds sales member.