The phrase, “Do it right or not at all,” speaks volumes to many. This sage advice passed down for generations can be applied to numerous situations — including fall forage establishment. Marvin Hall, professor of forage management at Penn State University, gives advice for fall seeding success in a recent Field Crop News newsletter.
The ideal window for fall seeding cool-season perennials is from mid-August to mid-September, Hall begins. During this time, the weather is warm but hasn’t yet reached the extreme heat that occurs in late fall. He explains that September rains help seeds establish quickly while the heat encourages growth.
“Producers need to be paying close attention to two things, seeding depth and seed-to-soil contact. More failures in establishing forages are the result of improper seeding depth than any other cause,” Hall cautions.
Forage seedlings struggle when planted too deep due to their limited supply of stored energy. Hall states that the ideal depth is typically not more than 3/8 inch deep, although a number of factors such as soil type, soil moisture, time of seeding, and firmness of seedbed play a role in this decision. Seeds planted deeper than 3/8 inch are unlikely to surface.
“A rule-of-thumb is that 5 to 10 percent of forages’ seeds planted should be on the surface after seeding,” Hall adds. “On properly firmed soil, an adult’s footprint should not be deeper than 1/2 inch.”
Hall stresses that seedbed preparation is key to ensuring accurate seeding depths. Soft, uneven soil inhibits regulation of seeding depth, causing irregular emergence and development of seedlings. Hall maintains that proper soil coverage entails a fine line between providing moist conditions for germination but not to the point that the shoot cannot surface.
“Forage seeds need to absorb at least their own weight in water before germination begins,” Hall notes. This can be achieved by ensuring seed-to-soil creating a firm seedbed and breaking up cloddy soil.
Hall states that ideally, maximum water movement into the seed from the surrounding soil should be as rapid as possible. Lack of adequate moisture or seed-to-soil contact can cause extended germination and irregular surfacing. To combat this, Hall recommends the use of press wheels on a grain drill or cultipacking after seeding.