Oklahoma Alfalfa
Oklahoma Cooperative Extension Service
Oklahoma Agricultural Experiment Station

CAN AN ALFALFA STAND BE THICKENED UP?

Try only on very thin, first-year stands. Attempts to sow alfalfa into old, thin stands usually result in few new seedlings becoming productive plants. Seedlings are more sensitive to pests that have built up, and seedlings must compete with the remaining mature plants for nutrients, water, and light. If an older stand has thinned to the point that it is not economical, the stand should be destroyed and a different species grown, before reestablishing alfalfa.   

There is a temptation to resow "drowned-out" spots. This is an acceptable practice only if the reasons for the wet spots are corrected. After improving drainage, a good seedbed can be prepared and alfalfa can be established successfully. Trying to fill in the wet spot, without correcting the problem, usually results in another stand failure.   

When young (less than 1 yr. old) alfalfa stands are thin (fewer than 5 plants per sq. ft.), overseeding with alfalfa in early spring or late summer may be successful. Again, the problem that caused the original poor stand must be corrected. There is little danger of autotoxic problems in thin stands less than a year old. 
 
Additional Information:   

• Alfalfa Stand Establishment Questions and Answers. OSU Extension Circular E-949  
• Alfalfa Stand Establishment. OSU Extension Facts F-2089