The best time to spray weeds is when you have weeds, right?
Or is it?
Maybe it makes more sense to spray before you have weeds, to keep them away.
Maybe you should just stand on constant guard on your patio with a bottle of weed killer, frantically surveying your yard for the slightest sign of weed activity.
That’s no good. You’d miss dinner.
When is the best time to spray weeds?
Let’s take a look.
Should You Set Your Alarm?
No need. There’s no best actual time of day to spray weeds. Just avoid windy days or rainy days.
Best Time to Spray Weeds: Before and After
One of the best times to spray weeds is before the weeds appear.
It’s called pre-emergent, and it’s a crucial part of weed control.
Pre-emergent weed control is designed to target the weed seeds before they sprout.
Crabgrass is a great example of the need for pre-emergent.
It’s crucial to apply crabgrass pre-emergent in early spring to target those weed seeds as they germinate and take root in the soil — so they don’t become more seed-producing plants.
But weeds are sneaky and tough, and some sneak through despite your best efforts.
Enter post-emergent products. They kill weeds once they already exist in their dastardly leafy form.
The Best Time to Spray Weeds: Throughout the Season
It would be great if we could announce in a booming voice: “The best time to spray weeds is May 7 at 3 pm.”
But it doesn’t work that way.
Weed control isn’t a one-time thing. It’s actually a continuous process.
Different lawn weeds here in Wisconsin and Minnesota are active at different times of year. Many of the peskiest spring weeds actually germinate in the fall.
Spring preventative treatments are based on soil temperature. Around here, that means our start time can range from March to May. Curative weed spray treatments occur from April through early October. 
This whole timing thing is kind of complicated. There’s a lot more involved than just applying products on your lawn.
That’s why you need a complete, proactive lawn care program that includes both weed preventative and curative treatments from early spring to late fall.
When Is It Too Late to Spray for Weeds?
Here in Wisconsin and Minnesota, October is the last chance to spray for weeds before winter sets in. And don’t spray too early. April or May is really too soon to kill weeds. They need to be actively growing for weed killer to work.
A Word About Mowing
Hold off on mowing when you’re planning to spray for weeds. Don’t mow for one to two days before or after spraying.
Why?
You want as much surface area of the weeds’ leaves available to "catch" the weed killer. If you mow right before, you often cut off those leaves.
After spraying, you want to give the plant time to absorb the weed killer and move it throughout the plant. If you mow it right off, it doesn't have time to make its way through the weeds.
While You’re at It, Improve Your Lawn with RainMaster
Yes, we’re deep in conversation here about the best time to spray weeds, but wouldn’t it be great if you hardly had to worry about weeds?
Weeds hate a healthy lawn. So make them really mad by choosing a proactive, comprehensive lawn care program designed not just to banish weeds, but to nourish your lawn year-round so its roots are healthy and its blades are thick and lush. Weeds will find it tough to sneak in. 
You choose from three different levels of lawn care programs at RainMaster, based on the results you’d like, how fast you want to see results, and your budget.
- Luscious Lawn is a high-end, proactive program that will promote amazing lawn care results. This is the program to choose for the quickest and best results, particularly if your lawn needs a lot of help.
- Terrific Turf, a mid-level option, is our most popular program to grow a thick, green lawn and deal with most challenges.
- Healthy Habitat is a basic plan that includes the elements you need for a better lawn.
When you’re ready to put your trust in us, we can’t wait to meet you — and help you make the best choices for your lawn.
Want to give weeds the boot, year-round? Request a quote today! We’ll review your lawn care options together so you can make a great choice. Then, you can finally enjoy watching your lawn transform and stop worrying about it.
