How Long Does It Take Weed Killer to Work

Deciding what weed killer you need to use in order to restore your lawn to a healthy state isn’t an easy task, but deciding how long you should wait afterward is also as hard, since it varies from one weed killer to another.

This Lawn Advisors guide will help you know how long does it take weed killer to work, then proceeds to specify how long it takes 4 of the most sold weed killers to work on different lawn weeds.

Additionally, you’ll have some extra tips you can use by the end of this guide, that’ll help you make up your mind on whether you should choose a specific treatment, and how to deal with different weed killers.

Let’s just start by stating that overusing weed killers can negatively impact your lawn and its surroundings, since it’s made to only be used under specific conditions and in certain amounts too.

How Long Does It Take Weed Killer to Work

Once you apply weed killer, it takes around 5-10 days to notice the initial effects of the weed control application. However, some types take a little bit more than that.

Generally speaking, initial effects of applying weed killer can be noticed within 7-10 days, while complete weed control occurs between 3 to 4 weeks, sometimes up to 32 days.

After you’ve given the weed killer time to work, this guide helps you decide what to do with the dead weeds after it’s all set and done.

Next are specific weed killer types and how long does it take every type of them to work.

How Long Does It Take Weed Killer to Work

How Long Does It Take Spectracide Weed Killer to Work

After applying Spectracide weed killer to weeds, you can notice weeds yellowing and wilting in a few hours.

However, it’ll take 7-15 days to completely kill the whole weed.

According to the user’s instructions on the Spectracide, you’ll need to cover treated areas to prevent the new weeds from growing near the affected area.

How Long Does It Take Gallup Weed Killer to Work

With using Gallup, you’ll start noticing the initial effects in the first few days.

Then, it’ll take up to 4 weeks to get rid of the whole pack of weeds, and complete the weed control, but it’ll still depend on the weather and how many other types of weed live around.

The good thing is, Gallup Home & Garden kills most weeds with a single application.

Here’s a video on Gallup weed killer, make sure you watch it to learn more about it and on how to use it:

How Long Does It Take Eraser Weed Killer to Work

Eraser weed killer takes a slower pace fighting weeds, as it has near-no activity in the soil. It works when applied directly to the foliage of the growing plants in your lawn.

It takes up to 2 weeks for plants to be completely dead after applying Eraser weed killer.

But the good thing is, since there’s no activity on the soil, there’ll be no residual effect too, and untreated plants near the targeted weeds will have trouble-free time growing properly.

Here’s how to use Eraser weed killer in your lawn:

How Long Does It Take Ortho Weed Killer to Work

It takes Ortho weed killer 2-4 weeks to completely kill the weeds in your lawn, but visible results can easily be noticed within the first few hours, since it’s a powerful and effective weed killer.

To achieve best results with Ortho weed killer, make sure to mow a couple of days before the application, to increase the weeds ability to absorb the herbicides.

Here’s how to use it:

How Long Do You Need To Stay off the Grass After Using Weed Killer

Generally speaking, you should stay off your lawn for a full day after applying the weed killer, without stepping on it or applying water too soon as well.

Some experts would say you should go for 2 days at least, depending on the weed killer you chose.

This guide talks in specifics about everything regarding how to work with your lawn after applying weed killer.

How Long Do You Have to Leave Weeds After Spraying?

Since we’ve already established that weed killers take around 5-10 days to be effective, and weeds need up to 32 days to die completely, it’s safe to say you’ll need to leave weeds for a similar period, in order to get rid of them for good.

However, different weed types take different time spans to die when targeted by different weed killers, so practice patience when attending to weeds after spraying them, and be thorough with how you notice different changes to their overall look after spraying them with weed killer.

How Long Do You Have to Leave Weeds After Spraying?

How Long Does It Take for Weeds to Absorb Weed Killer?

Weeds absorb herbicides in different ways, some absorb it within the first 7 days, while others take up to 15 days to absorb it completely.

This explains why it takes weed killers 5-10 days to be effective, and why some weed types take as long as a full month before they die to weed killers.

Is Spraying Weeds Better at Night or Day?

You’d want to spray the weed killer at the most effective time of the day for plants, and that’s at midday.

Since plants seek food and water during midday, it’d be perfect if you slip in the herbicides at that time, managing to kill them when they’re mostly active.


It takes weed killer around 5-10 days to work on weeds, and around 28-32 days to fully kill weeds, here’s the answer you’re looking for when asking How Long Does It Take Weed Killer to Work.

You also have 4 distinguished types you may look for and read about in this guide, as they work around the same time span, but in different methods and ways.

Leave a Comment