Every homeowner knows that a healthy lawn is a happy lawn. Weeds are more than just an eyesore. They can actually harm your lawn if given a chance to take over. What happens is that the weeds compete with the grass for light, water and the necessary nutrients plants need to grow and function. One important way to keep you lawn healthy is to prevent weeds from infesting it by using a pre-emergent. Here are some tips to help you successfully apply a pre-emergent this spring.

Timing is Everything

What they say about comedy is also true for lawn care: timing is fundamental. If you want to win the war on weeds, you need to think about timing when you use your pre-emergent. What was once a happy play area or relaxing backyard is now a wasteland of spreading weeds.

lawn with clover

Timing matters when applying a pre-emergent weed control because if you apply too late, the product will be ineffective. However, if you apply the pre-emergent when the weeds are still only seeds, you are quite literally nipping the problem in the bud.

For the most part, the two dates to remember are March 15 and September 15. To prevent summer weeds, the application date is March 15th, or when average soil temperatures reach above 50 degrees. September 15 is the fall application date that will limit any late fall growth and ideally eliminate weeds for the coming year.

Keep in mind, however, that these dates are only rough suggestions. Climate conditions and environmental factors can have a big impact on when seeds germinate. In some cases, repeat application may be necessary to improve weed control. Too much rain, for example, can alter the way pre-emergents work.

What Do I Need To Know Before Using A Pre-Emergent?

It is important to know what you are dealing with when it comes to weeds. First, weeds come in two major categories: grassy and broadleaf. Similar to grasses, weeds are either cool-season or warm-season. It is helpful to know what kinds of weeds you are dealing with when you are trying to find the right pre-emergent. Pre-emergent herbicides differ in their ability to conquer weeds. One product will not necessarily work on all of the weeds marring your lawn.

You also needs to know your weed types so you know when to apply the product. Weed species germinate at different soil temperatures. Because pre-emergent herbicides need to be applied prior to seed germination, it is necessary to know when the weed species in question will germinate.

In most cases, this depends on what part of the country you live in. Different weeds exist in different regions of the United States. Southern lawns with warm-season turf grasses like Bermuda grass and zoysia will typically deal with weeds like:

  • crabgrass
  • chickweed
  • Carolina geranium
  • henbit
  • purslane
  • clover

These can be prevented by applying a pre-emergent to the lawn well before seed germination happens.

How Does A Pre-Emergent Work?

Pre-emergents work by creating a barrier in the upper inches of soil early on in the growing season. When this weed prevention zone is in place, weeds are unable to penetrate it and thus never emerge on the surface. As soon as the weed seed germinates, it comes in contact with the barrier and dies. The herbicide does not stop the germination. The barrier stops the weed seed from developing.

What Tips Should I Know While Applying A Pre-Emergent?

During this time, it is important not to puncture the surface of the soil. If you do, you run the risk of weeds getting through the aerated points, thus defeating the purpose of the pre-emergent. Wait until another time to aerate your lawn.

Remember also that you do not need to drench your entire lawn with the product. The only reason you should do this is if, in fact, your entire lawn is actually covered with weeds. If you only have a few weed-stricken areas, these are the only areas where you need to apply the pre-emergent. It does not have to be used everywhere in order to be effective.