You might think winter means a halt to lawn care for a few months, but there’s actually a lot you can do. In warmer regions that get little to no snow, killing weeds in winter can be the best time for active weed control. Because your grass goes dormant in the winter, cool-weather broadleaf weeds and poa annua stick out like a sore thumb. Spot-treat these weeds with your weed killer of choice. Another good method for winter weed control is to apply a winter weed and feed fertilizer. To help prevent a lawn weed infestation next winter, apply a pre-emergent the following fall.
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How to Kill Winter Weeds
Even in regions with relatively mild weather and warm-season lawns, where weed growth doesn’t stop in winter, it’s a good bet you don’t want to spend hours outside in the cold, battling winter annual weeds. Here are some great low-effort, high-reward ways to kill any type of annual weed in the winter.
Spot-Treat Broadleaf Weeds
Many cool-season weeds are broadleaf weeds. Dandelion, henbit, common chickweed, and many others will remain green and growing through winter in temperate areas, even when the grass is brown and dormant. This means weeds won’t die but will stick out as green patches in your yard, making them easy to find.
Spot-treat these winter weeds with an herbicide application of your choice. Tenacity is a great post-emergent herbicide because it tackles both broadleaf weeds and winter annual weeds like poa annua.
If you’d prefer an organic herbicide option, consider BioSafe, which won’t leave any unwanted residue in the soil.
Because most lawns with Bermuda, St. Augustine, or any other warm-season grass go dormant in the winter, this is a great time for controlling weeds. An herbicide application to any weeds in the winter won’t kill grass that is dormant, so you will still have a healthy lawn in the upcoming spring.
Go All Out Against Invasive Winter Grasses
Most areas with warm winters are planted with heat-tolerant grasses that flourish in summer and go dormant in winter. However, these same regions are often infested with invasive grasses that flourish in colder weather and brown in the summer.
Invasive cold-weather grasses like rescuegrass and poa annua contribute to ugly brown spots in your lawn in summer. However, because they can handle cooler temperatures without going dormant, they are often green spots in your winter grass.
This makes winter the ideal time to spot invasive grass and tackle it. Not only does the invasive grass stick out, but it’s also more susceptible to weed and grass killers. Dormant grass is actually resistant to weed killers, so a winter weed treatment is one of the best times for use. There’s a lot less risk of harming your desirable lawn grass. It’ll come back strong in spring and the invasive grasses will be dead.
Try Winter Weed and Feed
Regions with mild winters can often benefit from a winter application of fertilizer or a winterguard weed and feed product that fertilizes grass at the same time it kills weeds.
Apply the fertilizer, a small layer of compost, or weed and feed during the winter months. This allows time for the nutrients in the fertilizer to soak into the soil while the grass is still dormant, meaning your lawn will burst into life in spring.
If you choose a weed and feed product for winter application, you can wipe out your winter weeds at the same time you strengthen your lawn for spring. Unlike many weed killers, which should be applied on a dry lawn, winter weed killers, like weed and feed, work well in damp winter conditions. This is because weed and feed contains bits of peanut husk soaked in weed killer. Damp conditions allow the peanut husk to stick to plants and release the winter weed killer they carry, more effectively killing weeds.
For southern state lawns with wet, mild winters, weed and feed is the secret trick of winter weed control.
- Scotts Turf Builder WinterGuard Fall Weed & Feed3 weed killer and lawn fertilizer controls weeds and feeds grass in the fall for a better lawn next spring
- Fall weed and feed kills over 50 listed lawn weeds, including clover, dandelion, plantain, morning glory, chicory, evening primrose, and purslane
- Apply weed control plus grass fertilizer to a wet lawn when weeds are actively growing and temperatures are consistently between 60°F and 90°F
Apply a Pre-Emergent in the Fall
While applying a pre-emergent won’t help you in the current winter, it is a great option to remember for the next fall.
When you apply a high-quality pre-emergent to your lawn in the fall, you help prevent weeds from ever sprouting. This is because pre-emergents kill weed seeds before they get a chance to grow and take over your lawn.
Soil temperatures need to be at least 70℉ (21℃) for pre-emergent to work, so don’t use this method if it’s already too cold. Plan your winter weed control application next fall.
Can You Spray Weeds in Winter?
You can spray weeds in winter, as long as your grass is dormant and temperatures are high enough. You should easily be able to identify any growing weeds by the patches of green in your brown, dormant lawn. Spraying winter weeds is as simple as applying weed killer to the desired areas.
If you have a lawn full of weeds, this weed killer is a great choice, as it won’t harm Bermuda grass, Zoysia, Ryegrass, and Kentucky Bluegrass. Simply attach it to a hose and apply it to your entire lawn.
- Kills weeds without harming your lawn.
- You can expect results within only a few hours.
- Easy-to-use on a variety of grass types.
RoundUp for Lawns can also be used as a winter lawn weed killer, especially if you have St. Augustine or any other Southern grass. It can kill many different types of weeds and is rainproof within 4 hours.
Because winter is typically a wet season in southern states, be careful about when you spray for weeds. Choose dry days with low wind for the best weed killing results. You’ll also want to read the product label before spraying winter weeds. Most herbicides require temperatures above 40 or 45 degrees Fahrenheit to work properly.
Should You Pull Weeds in Winter?
If you can find and identify actively growing weeds during the winter months, it’s a great idea to pull them out. As long as you live in a region where the soil does not freeze, you can pull weeds year-round. It’s often easiest to find and uproot hardy perennial weeds, such as dandelions, during the winter months when they stick out like a sore thumb among your dormant grass.
How Do You Kill Winter Weeds in the Spring?
If your winter weeds survived the cold months and are still present in spring, it’s time to act fast. Many of these weed species will survive until late spring, when they drop their seeds and ensure more weeds crop up in fall. Use Tenacity in the spring to kill winter annuals before the mature plant can drop its seeds. The upside to the herbicide is that it won’t kill grass seed or harm your lawn.
Killing Weeds in Winter
In many regions of the US, several species of weeds sprout in fall, survive through winter, and drop their seeds in late spring. These weeds rob your soil of nutrients and crowd out desirable plants and grasses. To fight back against winter weeds, spread preemergence herbicide in fall. If weeds are actively growing when your grass has gone dormant, spray them with herbicide or pull these weeds out by hand. You’ll have a weed-free lawn by spring.