By: Ron Honig, Crop Production and Horticulture Extension Agent
Late October to Early November is a great time to treat perennial broadleaf weeds such as dandelion and field bindweed. After a few shots of cold weather these perennial weeds, if not damaged by sustained hard freezes, are moving nutrients to their root systems this time of year. An application of 2,4-D or a premix containing 2,4-D and dicamba herbicides (such as Trimec or one of the Weed-B-Gone products) is easily absorbed by the weeds and translocated throughout the plant and roots.
Dandelion is a perennial plant and will survive the winter and green up again in the spring. New dandelion plants often sprout and emerge in late summer and thus are vulnerable to a fall herbicide application.
University tests show a fall herbicide treatment on dandelions often yields over 90 percent control the following spring verses only 50 percent or less control from a single treatment performed in the spring or summer.
Field bindweed is a perennial vine with whiteish-pink flowers and arrowhead-shaped leaves. Bindweed produces an extensive root system that once established, is difficult to decrease. Kansas State University research shows fall herbicide applications containing the chemicals dicamba and quinclorac provide the best control of field bindweed and the best chance of weakening and reducing the root system.
Chemical premixes containing dicamba and quinclorac are readily available at your garden supply store. To find these products you must read the portion of the label indicating the active ingredients in the product and not just the product name.
Henbit is a winter annual and sprouts in the fall up until sustained cold temperatures stop its emergence. When temperatures warm again, henbit then continues to emerge in late winter to mid-spring. In fertile lawns, henbit can grow a foot high or more with bright purple flowers. Unlike dandelion and bindweed, henbit will eventually die back when hot weather arrives.
Once henbit begins to grow in the spring and produce flowers, it becomes significantly harder to control with herbicides. Fall and early spring herbicide treatments will provide the best control.
The recommended use rates provided on the herbicide product label are normally sufficient to provide excellent control when applied in the fall. For best results, choose a day when the temperature is at least 50 degrees F during the daytime.
The one weed we are seeing so much of this time of year is prostrate spurge. It is that circular, low growing weed that seems to grow out of every sidewalk crack and when disturbed produces a white, milky sap. The good news is prostrate spurge is a summer annual and will freeze in the coming weeks and thus, will not require any herbicide treatments.
