When to Apply Crabgrass Preventer

How to Get Rid of Crabgrass

If you are looking for how and when to apply crabgrass preventer so that it never comes back then you are on the right path. I will tell you what you can do to kill and prevent those crabgrass once and for all.

Crabgrass looks like a light green clump of grass. It is considered a weed that automatically grows in the lawn in late May in the northern US states and as early as February in the South. 

You can identify them by looking at just their leaves. Their leaves are wider than average grass blades and look like you have a jungle in your yard that you want to remove as soon as possible.

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When to Apply Crabgrass Preventer

crabgrass
Stefan.lefnaerCC BY-SA 4.0, via Wikimedia Commons
spread Crabgrass Preventer

Time is a critical factor here for controlling this crabgrass weed.

The ideal time may vary depending on where you live, and the soil temperature, which depends on how much sun and shade your lawn receives on average.

  • The short answer is to apply the crabgrass preventer at the end of May in the Northern US states and apply it as late as February into early March in the Southern states.

Why is that timing? Crabgrass produces so many seeds. You can not control them just by removing them one by one.

The best way to kill them is to never let them appear in the first place by using a herbicide spray or the preventer.

Also, read: How to get rid of Dandelions in the Yard

crabgrass removal lawn care
Harry Rose / NY State IPM Program on Flickr

When is it Too Early or Late to Apply the Crabgrass Preventor

crabgrass in rock
original file: User:Richard Arthur Norton (1958- )CC BY 2.5, via Wikimedia Commons
When it is Too Early to Apply the Crabgrass Prevento

If you use it too early, it can break down before the seeds rise. If used too late, crabgrass will already start taking over your lawn, and there will be no point in using it.

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So you have to be very precious when you use them. 

If you apply the prevention in the late spring, it will be too late, as the crabgrass has taken over your lawn. So you have to do it before that time to get the best result.

On the other hand, if you apply the preventer a month before the last freezing day, it will be too early as those chemicals can break down, resulting in no effect on the weed.

The freezing day typically occurs in us is April 30 to May 20, but it may vary in your area.

What Should be the Soil Temperature

crabgrass and weed
NY State IPM Program on Flickr
What Should be the Soil temperature to remove crabgrass

The soil temperature should be under 60 degrees Fahrenheit. Apply the herbicide or crabgrass preventer when the ground temperature is above 60 degrees Fahrenheit or 15 degrees Celsius.

You can measure the temperature using a soil thermometer by inserting the meter in the pilot hole. It is easy and you can do it using a screwdriver and tape.

How to Apply the Crabgrass Preventer 

How to Apply the Crabgrass Preventer

Now you know when to apply crabgrass preventer based on your location, seasonal variations, and soil temperature. Now let’s understand how to apply this preventer.

  • First, wear gloves, a long-sleeved shirt, and a mask to protect yourself from the spray.
  • Apply the herbicide across your lawn as uniformly as possible using a spray bottle or big spray machine that farmers use in their fields to kill weeds.
  • Do not miss any spot as those crabgrass produce a lot of seeds, and they can quickly spread again through your lawn.
  • And do not aerate the lawn after applying the herbicide, as it can make the chemical ineffective.
  • Wait for two months to make the herbicide do its job and see the result.
  • If you think it is working, re-seed your lawn with grass. So that it can become fully green again.
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If your lawn is new, do not use the preventer right now, as it may kill all those grasses. Wait the time it takes to mow your lawn three times (21 days), and then use the preventer to have a minimum loss.

What to Keep in Mind Before Applying Crabgrass Preventer

crabgrass in brick
Harry Rose on Flickr
What to Keep in Mind Before Applying Crabgrass Preventer

You should follow the instructions below before you apply the herbicide to prevent maximum damage.

  • Do not apply the preventer to wet grass.
  • Apply it before the rain so that the rain can help the preventer get into the soil.
  • Do not seed your lawn when applying a crabgrass preventer. 

These are the primary concerns that you should know. And the technical part I have already discussed. 

So you are done learning how and when to apply crabgrass preventer. There is one more thing you should know and that is how to get rid of it permanently.

How to Get Rid of Crabgrass Permanently

crabgrass in the filed
Oregon State University on Flickr
How to Get Rid of Crabgrass Permanently

Follow the step to remove the crabgrass for life in your lawn.

  • Use a lawn mower to mow your lawn to keep the grass a consistent length and think in size.
  • Crabgrass requires sunlight to grow. So keep the grass as thick as possible to build shade on the soil surface. If you cut it too close, that will help crabgrass grow.
  • Do not cut more than a third of the grass height when mowing as that will help the grass get more sunlight and grow. 
  • Use fertilizer once a year by following the package instructions to prevent any kind of weeds automatically appearing.
  • If your lawn needs watering, then do it in heavy intervals so that those weeds do not get the booster to spread their roots deeper in the soil
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It is necessary to follow the precaution if you do not want to repeat the process of crabgrass removal. So follow it accordingly.

Last Words

So this is how and when to apply crabgrass preventer to your lawn and prevent it from making the place a jungle. Maintain and mow your lawn once a week, and use fertilizer to kill the weed once a year. Now get your essential things and kill those crabgrass.

Spreading Crabgrass Preventer FAQs

crabgrass in yard
NY State IPM Program at Cornell University from New York, USACC BY 2.0, via Wikimedia Commons

Can you apply crabgrass preventer too early?

No, if you apply it too early, it can break down before the seeds germinate resulting in a big mess in your front yard.

When is it too late for a crabgrass preventer?

Do not apply after the month of May, as it will start to germinate, and the infestation will take place.

How long crabgrass preventer lasts?

Crabgrass preventers last about 60 days, but it may vary depending on the crabgrass preventer you use.

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About Author

Nazim Ali

Nazim Ali is an engineer who loves fixing things at home. He loves to try new things and share the knowledge with the world.