Late Season Pasture Seeding for Northern Illinois

Jim Morrison
Extension Educator, Crop Systems

Late summer seeding time for perennial forage crops in the northern-third of Illinois is fast approaching. Since seedlings need 6 to 8 weeks of growth or be six to eight inches tall prior to a killing frost, August 10-15 are the suggested seeding dates.

Planning ahead is critical. Be sure there is no residue carryover potential from previously used herbicides. Have steps been taken to control problem perennial weeds? Soil tests should have been taken and any corrective limestone already applied. Fertilizer can be applied during seedbed preparation.

The above mentioned seeding dates are for cool-season grasses and legumes. Warm-season perennial grasses should not be seeded until the spring. If there is not adequate soil moisture, seed should not be planted. It is very risky planting seeds into dry soil.

A firm seedbed is needed to ensure good seed-to-soil contact. Follow the “footprint guide”- soil should be firm enough so a footprint no deeper than one-half inch remains.

A general rule of thumb is that seeds should not be planted deeper than five times their diameter. For most forage crops, the seeding depth should not exceed one-half inch. Tilling the seedbed may not be necessary, as no-till forage seedings can be made into small grain stubble, once the straw is removed.

Do not seed alfalfa following an older established stand. Compounds are released by the older alfalfa that inhibits the growth, development, and production of new alfalfa seedlings. If the alfalfa is more than one year of age, it is best to rotate to another crop before going back to alfalfa. If less than a year, alfalfa can be replanted.

Be sure to use high quality seed of known varieties and use the proper inoculum for legumes. Typically, seeding rates are the same as with spring seeding, but a companion crop should not be included. Late-summer seedings should not be harvested this fall.

Further information is available at Extension offices and in the Illinois Agronomy Handbook, http://iah.aces.uiuc.edu/

Jim Morrison, (815) 397-7714, morrison@uiuc.edu
Date: July 31, 2006