March 10, 2016

With warmer temperatures and what feels like an early spring, is it too early to plant alfalfa?

For most situations, the risks of planting now outweigh any benefits. If a mid-March planting is successful, alfalfa yield this year will be only a half ton higher at best compared to planting in mid-April.  Failing to get a stand, however, will cost several hundred dollars per acre when you consider both the reseeding cost and the value of your lost production.

Stand failure could be caused by a couple factors.  A return to more average temperatures would result in very slow germination and weak emergence of the alfalfa seedlings.  Seedling diseases can thin stands quickly under these conditions, even when using seed that has been treated with a fungicide.

And what about freezing?  Very young alfalfa seedlings can tolerate temperatures maybe as low as 20 degrees. Thus, freezing usually isn’t a problem early on.  The danger of freezing actually is greater after alfalfa reaches the third or fourth trifoliate leaf stage, or about 4 inches tall, which it is likely to do by late April or early May.  At this stage, alfalfa loses its cold tolerance and becomes more susceptible to freezing. Waiting to plant until April minimizes this risk.

Stand failures are expensive.  Planting during recommended times reduces that risk.

Bruce Anderson
Extension Forage Specialist