Treat Dandelions

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''Even well-established dandelions are easier to control then. At other times of year, sprays typically kill top growth, but sometimes leave the roots ready and able to sprout again,'' said Ward Upham, horticulturist with Kansas State University Research and Extension.

All three weeds are preparing for winter in late fall by actively moving materials from their leaves to the roots, Upham explained. So, a herbicide application will translocate down, too, killing the plants from the roots up.

Besides that, henbit, chickweed and some dandelions are young, tender and easier to control in early November, he said. Dandelions typically produce a flush of new plants in late September. Henbit and chickweed are winter annuals that go to seed during the growing season. Their next generation of plants germinates in October, getting a start on spring.

''The important thing to remember is that the better the weed is growing, the more weed killer will move from the leaves to the roots. Cold weather will slow or stop this process. So, you need to choose a day when it's 50 degrees or higher,'' Upham said.

The traditional herbicides to use are lawn-safe formulations of 2,4-D or combination products that contain 2,4-D, MCPP and Dicamba (e.g., Trimec, Weed-B-Gon, Weed-Out), he said. A newer product that will produce a quicker response -- especially as temperatures approach 50 F -- combines carfentrazone with 2,4-D, MCPP and Dicamba. It’s sold under such trade names as Weed Free Zone and Speed Zone.