The prettiest lawns still have a few weeds. Herbicides are useful in the war against annual, perennial, and biennial weeds, but it  is important to know when to use them and which ones are most effective against a common weeds that show up in your lawn every year. Pre-emergence weed killers are used on established lawns as part of an annual effort to fight problematic weeds. What are pre-emergent herbicides? They are chemical composition that are used before weeds take hold to kill off new root systems and keep them from growing.  You must learn how pre-emergent herbicides work, so you can decide what works best for your lawn. 

What is pre emergent used for? Pre-emergence weed killers are used before you see the weeds to prevent them from showing up in the garden or lawn. This doesn’t mean the chemicals interfere with germination but rather they stop the formation of new root cells in baby weed plants. Without weeds, the seedlings cannot continue to feed and grow and they just die back. This process happens at the soil level under the blades and thatch of the grass so you don’t ever have to see the sprouted weeds. late winter and spring when temperatures are cool is a great time to apply pre emergents. How Pre-Emergents Work The chemicals in pre-emergent weed killers are not effective on vegetative buds that sprout from existing roots or rhizomes. They also cannot be used on a prepared grass seedbed because their root stunting action in young plants will also affect sprouting grass.

Why Do You Use Pre-Emergent Weed Control?

Pre-emergent weed control is designed to stop a variety of weeds before they appear. This happens by applying a protective layer of pre-emergent herbicide to your lawn, preventing the weeds from entering the soil barrier.

What Is The Best Time Apply Pre-Emergent Weed Control?

Throughout the southeastern regions of the United States, like Summerville, SC it is imperative to apply pre-emergent weed control during the right time of year. Some suggest that applying it when the temperatures are between 50-60 degrees is the best time. When herbicide is not applied prior to germination, it is almost non effective. This means the protective barrier MUST be applied before weeds have the opportunity to germinate.

You Should apply the first round of pre-emergent before “the dogwoods start blooming”. It can be weather dependent, but typically the best time to apply a pre-emergent weed control treatment in the southeast is during the months of February and March.

After March, you will be less likely to see good results from a pre-emergent weed treatment. The exception here of course, would be if it had been a particularly cold season, leaving seeds dormant longer.

How Long Does Pre-Emergent Weed Control Last?

‍Every product  different but normally, you can expect one treatment to last up to 5 months. However, It is recommended tp apply a split application approximately one month apart to maximize effectiveness.

It is also important to select a good product. If you are planning to try and treat your lawn yourself, always be sure to read the labels, so you understand how long the manufacturer suggests their product lasts. A professional landscaper will be able to answer this question for you.

What Types of Weeds Does Pre-Emergent Weed Control Treat?

Pre-emergent weed control is effective prior to germination on most all summer annual weed varieties. This includes common weeds like crabgrass, chickweeds, dandelions.

Can Pre-Emergent Weed Control Harm My Lawn?

Pre-emergent weed control is not harmful to your lawn. If you plan to plant new seeds for ornamental plants to compliment your landscape, or new grass seed to your lawn, treatment should not be applied to those areas prior to germination.