When To Apply Crabgrass Preventer? The Best Time

When-To-Apply-Crabgrass-PreventerDo you have crabgrass problems? If you do, it’s time to start applying crabgrass preventer. This essential garden tool helps control and prevent crabgrass from spreading and is a key part of any garden maintenance plan. Here are four times when you should apply a crabgrass preventer.

Springtime is a great time to tackle your lawn care, but one task always challenging is preventing crabgrass. Crabgrass is a very tough weed to get rid of, and the best way to prevent it from returning is to apply crabgrass preventer regularly.

When To Apply Crabgrass Preventer – Pre-Emergent Timing

Crabgrass is a very common weed that can be hard to eliminate. If you’ve struggled to eliminate crabgrass, you must know when to apply crabgrass Preventer. Crabgrass is among the most common weeds in North America, and it can be challenging to get rid of it without resorting to harsh chemicals. However, there are other, more effective ways to eliminate crabgrass. Apply Crabgrass preventer isn’t just for crabgrass! It’s also an effective way to control many other weeds, such as dandelion and lamb’s quarters. 

Benefits of Crabgrass Preventer

  1. It is a quick-acting, systemic herbicide. It should be applied before crabgrass germinates to prevent the weed from growing and re-sprouting. For best results, use in the fall, after the danger of frost has passed but well before the first killing frost of winter.
  2. Applying this product at any time if crabgrass is an issue is recommended. In addition to preventing new seedlings from growing, preventative products will control existing plants.
  3. You can use a it to avoid future vegetative germination of your plant and inhibit root growth, which will keep weeds from spreading.
  4. It is typically applied in the month of May, before crabgrass germinates and sprouts.

The Right Tool

 The Right Tools

If you want to prevent crabgrass from growing in your lawn, there are several tools that you may use, including:

Fertilizers: Fertilizers can effectively prevent crabgrass from coming up in your yard, especially if they contain nitrogen and phosphorous, which will help promote healthy growth in other types of grasses.

Mowing is another way to prevent crabgrass from coming up in your yard because it will cut down on any new growths before they can take over the entire area where they are located.

Preemergent: A preventer is a preemergent herbicide that is applied before crabgrass germinates. The best time to use a preemergent crabgrass preventer is when the soil temperature reaches 50 degrees Fahrenheit or higher. It takes about five days for this chemical to get its full effectiveness.

The Right Tools

Several crabgrass preventers are available at local nurseries and home improvement stores, including Ortho WeedB Gon Max, Scotts, and Halts Crabgrass Control. When choosing a product, look for those labeled “selective” rather than “nonselective.” This means that it will stop the growth of certain types of plants while allowing others to thrive.

Time To Apply

When To Apply Crabgrass Preventer

Before Rain

When applying a crabgrass preventer to your lawn, it’s best to use it before the rains. The water from the shower will help keep the product dry until it can be watered in after the rain has passed. 

Windy Day

Applying your crabgrass preventer on a windy day will blow away before it can be steeped in.

Apply Crabgrass Overnight

If you’re going out of town for a few days and want to ensure your lawn stays healthy while you’re gone, apply some crabgrass preventer before you leave and let it sit overnight.

Then when you return home and see that your lawn still looks great, come back in with a sprinkler or hose and water down any remaining product that isn’t appropriately applied (leaving an inch or two of water between each application).

Dry Ground

Crabgrass preventer should be applied when the ground is dry, but not before rain or after rinsing with water. The best time to apply the crabgrass preventer, is in early spring, when the grass grows most rapidly. You can use it again during late summer and fall to protect newly planted seedlings.

Liquid and Granular Formula

Crabgrass prevents availability in liquid and granular formulations, depending on how much control you want for your lawns.


Bromoxynil works by inhibiting certain enzymes in plant cells responsible for regulating plant growth and development, while triclopyr stops cell division at an early stage of plant development. Crabgrass preventer can be applied any time before or after rain. Apply crabgrass preventer at a rate of 1-2 lbs per 1000 sq ft.

Right Time of the Year

Four times in a year when you should apply crabgrass preventer:

Spring and fall

These two seasons are the most susceptible to crabgrass infestation. The best time to apply it is early in the spring, before the grass has completely emerged from its winter dormancy, and earlier in fall before the first frost.

Early summer

If you live in a hot climate area, you must be especially vigilant about applying crabgrass preventer to your lawn during this season. The heat will cause your grass to become more susceptible to weeds, and since crabgrass germinates quickly, it can easily overtake your lawn if you aren’t careful.

Late summer/early fall

Crabgrass germinates year-round, but it’s especially active from July through September — which means it’s prime time for this pesky pest to sneak into your yard!


  1. Remove any weeds with a hand cultivator or hoe in the area to be treated.
  2. Mix concentrate according to label directions and apply with a licensed pesticide applicator or use your spray equipment.
  3. Wear protective clothing before applying, including long sleeves, pants, boots, and gloves. Avoid direct contact with skin and eyes. Wash hands after application and keep children away from treated areas until all symptoms have cleared up for at least 24 hours after the application has been completed (see label directions for specific instructions).


  • Do you know when to apply crabgrass preventer?

Apply it according to the manufacturer’s instructions. Wear safety gear such as gloves and goggles because this product contains chemicals that can cause skin irritations or severe eye injuries.

  • Is your pre-emergent crabgrass control being applied on time?

Pre-emergent crabgrass control is a vital part of treating your lawn for crabgrass. If it’s not applied on time, the weed will quickly become resistant and require higher herbicide concentrations to be effective.

  • How do you get rid of crabgrass in the rain?

Crabgrass is a tough weed to get rid of, but there are ways to combat it. One way to work for you is using Crab Grass Killer from gardeners edge.


Thanks for reading this article. After reading this article you should be able to determine the best time to use a crabgrass preventer on your lawn. Keep in your mind that there is no perfect time, as weather conditions and the intensity of crabgrass growth can vary yearly.

However, by following these guidelines, you’ll be on the right track to preventing crabgrass from taking over your lawn!

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