October 12, 2009

Timing is everything. That's particularly true with thistle control. And October to early November is one of the best times to use herbicides for thistle control.

If you had a thistle problem this year, check infected areas for the small, flat rosette seedlings typical of fall growth. Seedlings are especially sensitive to certain herbicides and are more effectively controlled in the fall.

Milestone, one of the newer herbicides, is very effective. Two other effective herbicides are Tordon 22K and Grazon, but be careful with them as they can also kill woody plants, including trees. While it’s still warm 2,4-D will work well, but you will get better thistle control by using a little less 2,4-D and adding a small amount of Banvel or dicamba to the mix.

Herbicides to help control thistles in pastures include Redeem, Ally, Curtail.

When using any of these herbicides, read and follow label instructions, and be sure to spray on time. Next year, avoid overgrazing these pastures so stands thicken and can better compete with thistles.

Bruce Anderson
Extension Forage Specialist