Timely Topics

Late Summer through Fall

Now that summer is pretty much over many of the weeds have sprouted, flowered and seeded and are done with their life cycle. Noxious weeds like perennial pepperweed (tall whitetop), poison hemlock, musk thistle and Scotch thistle are beyond control for this year. However, noxious weeds such as leafy spurge, Russian knapweed, Russian-olive, Canada thistle and field bindweed (morning-glory) are coming into some of the best time for control. These are perennial weeds that will begin to take sugar reserves into their root systems to survive the winter. By applying the correct herbicides at this time the weeds will take the herbicides down along with the sugars which will in turn kill the weeds more effectively.

Prime time for spraying leafy spurge, Canada thistle and field bindweed will be in September as the temperatures start to fall and we start to get some light frost. If you have a license for Picloram (Tordon 22K) that is ideal for these weeds, otherwise herbicides such as dicamba+ 2,4-D (Weed Master)and triisopropanolammonium (Milestone) are effective for Canada thistle and the dicamba+ 2,4-D (Weed Master) will do well for leafy spurge.

Controlling Russian-olive will be effective until a hard freeze occurs. 2,4-D Amine or Ester can be sprayed on the leaves up until they begin to lose color. Cut-stump treatments of 2,4-D, glyphostate (Roundup), picloram products (Tordon) can be made up to the hard freeze (please note that the Weed Department does not perform cut-stump treatments).

The most effective time to control Russian knapweed is from late September until the ground freezes. The weed may look dead but small buds at the ground level are active and highly susceptible to treatments of triisopropanolammonium (Milestone) or clopyralid MEA (Curtail). The Weed Department has treated many acres in the fall will tremendous results, 90 to 100% control, the following year.

With all herbicides we recommend the use of a quality surfactant to aid in the uptake of the herbicides. Applying herbicides without surfactant is normally a waste of time.

Other herbicides with these same active ingredients may be just as affective, if you can find them, and they may be less expensive as well.

For more information on controlling these and other noxious weeds continue browsing this site or call (435) 789-1073 .