when to apply weed killer

Using weed killer at different times of year will impact how effective it is, so knowing the best time to kill weeds can save you a lot of time an effort. You also want to make sure that you’re only killing the weeds, and not the surrounding grass and plants when you apply it.

Read our handy guide to find out the best time to apply weed killer.


When to apply weed killer

As a general rule, you’ll only be able to kill weeds when they are actively growing. This will be between May and October. To avoid having to reapply weed killer, hand weed the first few that pop up at the beginning of spring and wait until at least June to apply weed killer. This allows enough time for the majority of the weeds to grow in so you can tackle them all in one application.

If you do need to apply weed killer again, do it before it gets too cold to do so. Just make sure that the weed killer you use is suitable for repeat usage.

You could also wait until mid-August or early September to apply weed killer. This will almost guarantee that all potential weeds will have grown in.


When is the best time to apply weed killer?

While the time of year is arguably the most important factor to consider when applying weed killer, there are lots of other elements to be aware of. These include:


Weather conditions

It’s best to apply weed killer in cool, calm weather conditions. If it’s too windy it can blow the spray off the weeds and onto nearby grass and plants. Avoid freezing conditions because this will make the weeds harder to penetrate. You also want to avoid strong sunshine. If you’re applying weed killer in the height of summer, wait until the evening to apply weed killer.


How fertilised your lawn is

A fertilised lawn provides the best conditions for applying weed killer. Make sure you fertilise your lawn around early spring to allow the grass to become strong and dense before applying weed killer in the summer.


If your grass is dry or wet

Applying weed killer on wet grass will likely dilute it, increasing the likelihood of you having to reapply at a later date. Make sure your grass is fully dry before applying and keep an eye on the weather report to check that it won’t rain for at least 4-6 hours after.


If your grass is mowed

You can mow your grass before applying weed killer but just make sure you don’t cut it too close otherwise you might also remove the tops of the weeds. This will leave you with less surface area to properly spray them with weed killer.

It’s also advised that you don’t mow your lawn for at least 3 days after applying weed killer.


Get rid of your weeds for good with Lawn & Weed Expert

Save yourself a lot of time and money and get in touch with Lawn & Weed Expert to treat your weeds. We don’t just treat the visible part of the weed; we also deal with the underlying conditions that promote weed growth in the first place. Request a FREE survey now to get started.

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