Fall Is the Sweet Spot for Weed Control

Home Gardeners

Tuesday, November 3, 2026

Rachel Anderson, Nebraska Extension Educator

White flowers and green vines growing on dry, cracked soil under sunlight.

Fall is a good time to target field bindweed and other problem perennials. Image from Adobe Stock.

Tired of seeing herbicide drift damage on your trees while lawn and landscape weeds thrive through spring and summer? If so, it might be time to trade in your early-season spray regimen for something new—starting this fall.

Don’t wait until next year to deal with persistent weeds.

Research shows that late September through early November in southeast Nebraska is the best time to target many biennial and perennial weeds including ground ivy, thistle, mullein, bindweed, leafy spurge, white clover, plantain, dandelion and even broad-leaved woodies like mulberry and Siberian elm. This is because systemic herbicides such as glyphosate are most effectively translocated into plant roots as these weeds prepare for winter. Even those not completely killed are often too weakened to survive the cold months, making fall treatment a useful strategy for weed control.

When spraying in the fall, keep in mind that it only works on plants that are green and growing. Leaves turning color or dropping means the plant is entering dormancy, which is too late for effectiveness. Apply well before a hard freeze, when 7-10 days of warm weather are forecasted with temperatures reaching above 50 degrees Fahrenheit. For weeds still in bloom, spray at sundown to avoid bees as they forage or mow off the flowers first.

Watch for winter annuals, too.

Late-season herbicide applications also work for winter annual weeds including henbit, chickweed, prickly lettuce, shepherd’s purse, annual bluegrass, downy brome and field speedwell. Winter annuals are unique in that they sprout late in the year, appearing as a seedling or small rosette of foliage. Hand-pulling or hoeing when they are at this stage is an alternative method that’s chemical-free; just be sure to cover any disturbance to the soil with a few inches of leaf or wood mulch so new weeds don’t pop up.

Gloved hand using a gardening tool to dig soil, surrounded by grass and plants. — Winter annuals including prickly lettuce and shepherd's purse sprout as low rosettes late in the year, which are relatively easy to weed at this stage via hoeing or pulling. Image from Adobe Stock.

As for summer annual weeds like crabgrass, goosegrass, foxtail, pigweed, Asiatic dayflower, prostrate spurge, purslane and kochia, their life cycle ends as winter begins so treatment now would be a waste. Wait until early- to mid-April to apply a pre-emergence herbicide if you think they’ll be a problem next year.

Skip early-season spraying and your trees may thank you.

Along with making sense for effective weed control, timing herbicide sprays later in the year has the added benefit of lowering the risk of injury to plants from off-target drift. Nebraska Extension gets many calls each spring about oaks, redbuds and other trees with distorted and discolored leaves that remain twisted, cupped or curled for the rest of the growing season. While unintentional damage from herbicide drift is not the only cause of such symptoms, it can happen when lawns and landscapes are sprayed with herbicides as nearby trees and shrubs leaf out.

Curled green leaves on a branch against a clear blue sky. — Tree damage (shown here as leaf cupping, curling and twisting) can occur when herbicide is carried by the wind away from where it was sprayed, especially in spring and summer as trees are actively growing. Image from Laurie Stepanek.

Tree leaves are at their most vulnerable when they are young and newly emerging, usually in April for Nebraska. Avoiding the use of herbicide sprays during this time could help lessen the problem of damage from drift, especially with more volatile products containing 2,4-D or dicamba. And it’s not just trees—tomatoes and other garden plants can be sensitive to drift, too.

Do what you can to prevent drift when applying herbicide.

To minimize drift when herbicide application is necessary, only spray on days when the air temperature is below 85 degrees Fahrenheit and wind speed is between 3-10 miles per hour. It also helps to adjust your nozzle to emit larger droplets—not a fine mist—and to hold the spray nozzle only 2-3 inches from the weed.

Thermometer in a garden surrounded by colorful flowers and green shrubs. — When spraying herbicide, make sure temperatures are below 85 degrees Fahrenheit and windspeeds are between 3-10 miles per hour to help minimize drift. Image from Adobe Stock modified by Rachel Anderson.

A drift guard or spray shield serves as extra protection when attached to the head of a sprayer wand. If you can’t find one compatible with your sprayer, you can make it yourself by cutting off the bottom of a large soda bottle or milk jug, sticking the nozzle through the original opening and duct taping it in place.

White plastic jug at the end of an herbicide sprayer wand among green leaves and shrubs outdoors. — A simple drift guard can be handmade to fit onto an herbicide sprayer. Image from James H. Miller, Bugwood.org.

Another tool designed to prevent drift is a weed wand, which is used to wipe herbicide onto a plant rather than spraying it. Buy online or learn how to make your own via this link: https://lancaster.unl.edu/how-make-diy-herbicide-wand-drift-free-weed-control-step-step/.

Person in gloves applying herbicide to weeds along a curb with a long white tool made out of PVC pipes. — A weed wand is a tool that applies herbicide by daubing or wiping for drift-free weed control. Image from Rachel Anderson.

Nebraska Extension is here to help.

Knowing what kinds of weeds you have is an important first step in any management plan. Feel free to reach out to Nebraska Extension for help with identification. When using herbicides, always read and follow the label directions and use the personal protective equipment recommended to keep yourself safe.