Issue No. 7, Article 5/May 8, 2009
Is It Too Late for Spring Forage Seedings?
Wet soil conditions and delayed field work have prompted questions on how late alfalfa seedings can be made. As is commonly known, spring seedings tend to be more successful in the northern half of Illinois than in the southern half.
The typical spring planting window is March through mid-April for central Illinois and March through late April for northern Illinois. Mid-May is considered to be the deadline for spring seeding. The degree of root and seedling development into early summer is the determining factor for setting the end point for spring seeding. Root systems should be actively growing in the top 3 inches by 3 to 4 weeks after germination.
As spring seedings are delayed past mid-May, the likelihood of consistent, successful stand establishment is low due to high soil temperature, lack of soil moisture, and increased weed pressure. Irrigation provides the opportunity to extend the seeding period later into the spring.
If oats are used as a companion crop, their rate of seeding should be reduced to half of normal (or even eliminated) with May seedings.--Jim Morrison