Applying your pre-emergent herbicide is one of the most critical steps to ensuring you have a lush, attractive weed free lawn! And it begins in the spring!
First what exactly is a pre-emergent?
Pre-emergent herbicides are molecules that specifically target emerging weeds in the lawn area. There is a common misconception that the pre-emergent herbicides kill existing weeds. While technically the death of emerged weeds can occur from pre-emergent herbicide application, pre-emergent herbicides are used to prevent weeds from emerging and establishing in your lawn.
How are pre-emergent herbicides applied?
The herbicide is delivered in granular form through Fertilizer Products with Pre-emergent herbicides impregnated onto them, or in a liquid form through a tank sprayer application.
How do pre-emergent herbicides work?
- These herbicides work by creating a very thin barrier of herbicide along the surface of the soil. If applied in granular form, they are activated by rainwater or irrigation water. If your pre-emergent is applied in liquid form, the herbicide is mixed with water and sprayed onto the soil surface in the water.
DID YOU KNOW? Weed seeds are always present in the soil! Additional weeds seeds can be introduced to your lawn from birds, wind, debris washing with rainwater or that neighbor that needs to read this blog!
- Existing weed seeds germinate and come into contact with the herbicide barrier. The herbicide is absorbed by the weed creating certain death in annual weeds.
- These barriers continue to work for a period of time typically 90 days, with longevity dependent on microbial activity in the soil, water, temperature and sunlight (UV degradation)
When should I apply my pre-emergent herbicide?
Summer annual weeds such as crabgrass begin to germinate when soil temperatures reach 55 degrees. A clear indicator would be forsythia starting to bloom. In fact, if you see forsythia blooming.... it's time to get it done.
You can visit our Lawn Care Programs section a get a specific program for your lawn type and specific area.
How often do I need to apply pre-emergent herbicides?
One application in most cases WILL NOT provide the weed prevention you are looking for. Most pre-emergent herbicides act as building blocks on each other, to offer the protection from weeds. Therefore, in the spring (unless you are re-seeding) you will need two applications 60-90 days apart. The stacking of these two applications will in almost all cases provide you solid weed prevention until the early fall! If you are a proud owner of a bermudagrass, centipede grass, St Augustine grass or zoysia grass lawn, you will also want to make a third pre-emergent application in the fall as well. More on the timing of these applications can be found by visiting our Lawn Care Programs section.
FAQ's Regarding Pre-Emergent Herbicides
Q. Will these products hurt my pets or other domesticated animals?
A. As with any granular product applied to your lawn, you should always water the lawn after application. This ensures the granules travel down to the soil surface where they are needed. Generally speaking, all of the granular products offered at AgChimp are safe for people and pets once watered in and allowed to dry.
Q. Are your Pre-Emergent products going to hurt my grass?
A. Both the AgChimp 18-0-6 30% Slow Release w/.29% Prodiamine Pre-emergent and the AgChimp 5-0-30 2% Iron w/ .29% Prodiamine Pre-emergent products are safe for use on all home lawns. Both of these products are designed to cover 5,000 sq. ft. of lawn area. Always read and follow labeled instructions.
Q. Should I water my lawn after application?
A. Yes. Pre-emergent barriers are activated by water. Ensuring proper watering of the product into the lawn area will ensure proper activation of the weed control barrier.
Q. Should I hire a lawn care company to apply my pre-emergent herbicide?
A. AgChimp pre-emergent herbicides plus fertilizer cost between $5-$6 per 1000 sq. ft. to apply yourself. Most professional applicators to a good job. You have to decide whether you want the pride and bragging rights of doing it yourself (for less money) or hiring a professional. Always make sure any professional you hire are licensed (both business license and pesticide applicator license) and insured.
Have another question? Feel free to Contact Us.