Fall Treatments for Broadleaf Weeds

When to get the weeds out depends on the weeds!  …Broadleaf weeds are classed as annuals and perennials with annuals further divided as winter and summer annuals.   …Fall is an excellent time to rid the lawn or garden of winter annuals because they germinate in fall or late winter and reach maturity in late spring.  …Some perennial broadleaf weeds are also better controlled in the fall when the weeds are trans-locating food reserves from tops to roots in preparation for winter.                                                                                                        

In our area henbit, common chickweed and Shepherd’s-purse thrive like the weeds they are!  All are winter annual weeds.

chickweed

henbit

Some of our common perennial broadleaf weeds are plantains, dandelions, white clover, poison ivy, docks and even violets.


narrow leaf plantain

common plantain

What is the “Brew” to use on these uglies!  Pre-emergent herbicides (chemicals applied before germination of weed seeds) are effective in controlling winter annuals when applied in the fall.  Post-emergent herbicides may be applied to still-green perennial broadleaf weeds effectively during the early fall as well as winter annual seedlings. 

When purchasing an herbicide, consider the plantings surrounding the weeds. The use of an herbicide to control weeds may also limit, damage or be a hazard to surrounding landscape plants or future plantings. Trifluralin is a pre-emergent herbicide found in several manufacturers’ products.  It is able to be used around ornamentals, vegetables and fruit and controls many winter annuals including common nuisances in our area.  Isoxaben, also a pre-emergent herbicide, is a weak grass killer, but controls chickweed, henbit, dandelions, and plantains. 

Common post-emergent herbicides include 2, 4-D, glyphosate and dicamba. Trade names of manufacturers using these herbicides are Round-Up, Preen and Ortho Weed-B-Gone Max.  Products containing glyphosate (Round-Up) are non-selective and will kill broadleaf plants as well as grasses. Products containing solely, or a combination of 2,4-D and dicamba target broadleaf weeds only and are usually not harmful to grasses.

CAUTION:  Always read the manufacturer’s directions for use carefully.  Apply and use only as directed.  Dispose of product or containers in contact with product as the manufacturer’s label states.                                                                                                            

Sources: Home Lawn Weed Control. (MU Guide Sheet G6750) and Manufacturers of Round-Up, Preen and Miracle-Gro.

Hickory County Master Gardeners are not endorsing or recommending the use of any particular trade named product. Trade names are used for example purposes only.

Posted:  9/13/2013