As summer winds down and cooler temperatures appear, many homeowners with cool season lawns will begin to prepare their lawns for autumn. While fall brings relief from the scorching summer sun, it also marks the time where most homeowners find stubborn weeds in their lawns.
Understanding how to treat lawn weeds in fall is essential for maintaining a healthy, vibrant lawn year-round. In this guide, we’ll explore the best lawn treatments for controlling lawn weeds in fall and how to prevent them with regular lawn maintenance.
Types of Weeds That Thrive in Fall
Fall is a critical time for both annual and perennial weeds. Understanding the different types of weeds and their growth patterns can help you target them effectively.
Annual weeds, such as annual bluegrass (poa annua) and crabgrass, grow, flower, and die in a single season but often leave behind seeds that sprout the following year. Perennial weeds, such as dandelions and clover, live for multiple years. They establish deeper root systems, allowing them to survive through winter and regrow year after year.
Common weeds to watch out for in the fall include poa annua, chickweed, and henbit. Annual bluegrass, in particular, is a winter annual weed notorious for invading lawns during the cooler months. Seeds from this weed germinate in late summer to early fall, once soil temperatures fall below 70°F. The seedlings mature in fall, lay dormant in winter, and flower and produce seeds in late spring/early summer.
While annual weeds die off at the end of the season, perennial weeds can survive through the winter and come back stronger in the spring. To prevent these from becoming a problem, fall is the ideal time to take action.
The Best Time to Apply Weed Control
When it comes to fall weed control, timing is everything. The ideal time to apply weed treatments is when weeds are still actively growing. This allows the herbicide to be absorbed effectively, ensuring it kills the weeds before they can produce seeds.
There are two main types of weed controls you can use in the fall: pre-emergent weed control and post-emergent weed control.
Pre-Emergent Weed Control
Pre-emergent weed controls work by preventing weed seeds from germinating. They are best applied early in the fall, before weed seeds begin to germinate. This is especially important for controlling annual weeds like poa annua, which typically start their seed germination in the fall and continue growing through the winter.
If you don’t plan on seeding apply either Season Long Weed Preventer or Veri-Green Crabgrass Preventer plus Lawn Fertilizer in early fall. If you do plan on seeding in fall, however, we recommend waiting 60 days after seeding to apply either product to ensure new grass seedlings germinate properly.
To effectively prevent weed growth, it’s important to apply a pre-emergent weed control at the right time. This is usually when soil temperatures drop below 70°F, signaling that weed germination is about to begin.
Post-Emergent Weed Control
If lawn weeds are already taking over your lawn, you’ll need to apply a post-emergent weed control. These products work by killing weeds that are already established. Fall is an excellent time to use post-emergent weed control, such as Lawn Weed Control, because weeds are still actively growing and will absorb the herbicide more effectively. This is especially helpful for tackling tough perennial weeds like dandelions and clover.
If you’d like to tackle your weed problem immediately and still want to seed in fall, we recommend waiting 30 days to plant grass seed post-application. If you’ve already seeded , however, don’t fret! You can still apply this product to control weeds in fall by waiting 30 days and then applying it to your lawn. Make sure to carefully read and follow all instructions on product labels before applying any weed controls.
How to Prevent Fall Weeds
In addition to using herbicides, proper lawn care practices can help reduce the presence of weeds in the fall. Here are a few tips to ensure your lawn remains healthy and less susceptible to weeds:
Mow Regularly
Mowing regularly helps to grow and maintain a healthy, thick lawn to crowd out weeds. Mow high, setting your mower to about three to four inches.
Fertilize Your Lawn
Applying a balanced fertilizer in the fall, such as Winter Survival Fall Lawn Fertilizer, helps nourish and strengthen your lawn’s root system, making it more resistant to weed invasion.
Water Appropriately
Fall often brings cooler temperatures and less evaporation, so reduce your watering schedule accordingly. Overwatering can create conditions that favor weed germination.
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The Bottom Line
Taking control of fall weeds requires a proactive approach. By using both pre-emergent and post-emergent weed controls at the right time and following good lawn care practices, you can prevent annual weeds like poa annua from taking over and stop perennial weeds from establishing deeper roots.
Remember, controlling lawn weeds is an ongoing process that requires attention throughout the season. Patience is key – with the right treatments and timing, your lawn will be free from fall weeds and well-prepared to thrive next spring.