When it comes to weed prevention in home lawns, nothing is quite as effective as a pre-emergent herbicide. Because most weeds don’t emerge until soil temperatures warm up, spring is an excellent time to prevent weed growth by using pre-emergent products. The herbicide’s ability to target weeds during their germination process makes it one of the best solutions for maintaining a weed-free lawn throughout the year.

As with all herbicides, proper application is crucial for the product to be effective. Because pre-emergent herbicides differ greatly from post-emergent herbicides, homeowners must take the time to learn the basics of pre-emergent weed control. If you’re wondering how to control weeds in the spring, read on to discover the purpose of pre-emergent herbicide applications and how to properly use them.

What is a Pre-Emergent Herbicide?

Before we dive into how to properly use pre-emergent herbicides, it’s helpful to understand the difference between pre-emergent and post-emergent products. As the name suggests, pre-emergent herbicides are designed to be used before weeds “emerge” from the soil. Post-emergent herbicides, on the other hand, are meant for tackling weeds after they appear.

Although it’s often thought that pre-emergent products prevent seed germination, they actually kill weeds during the germination process. This is made possible due to the pre-emergent herbicide’s ability to prevent plants from producing protein, which is necessary for cell division. As a result, the plant’s root development is damaged, eventually causing the weed to die. The pre-emergent will continue working in lawns by acting as a root pruner to stunt the weeds’ growth.

Which Spring Weeds Do Pre-Emergent Herbicides Control?

As a homeowner, you are likely aware of several different weeds that appear in your yard each spring. Some of the most common weeds that quickly take over lawns include crabgrass, plantain, goosegrass, dandelions and lespedeza. Whether your lawn is battling vining plants or broadleaf weeds and grasses, a pre-emergent herbicide is an effective method for controlling spring weeds in your lawn. From crabgrass and quackgrass to dollarweed and common lespedeza, you can be sure a pre-emergent herbicide will keep your lawn weed-free throughout the spring and summer.

When to Apply a Pre-Emergent Herbicide in the Spring

Pre-emergent herbicides should be applied to lawns at least twice a year, once in the spring and again in the fall. When applying a pre-emergent in the spring, be sure to apply before the ground temperature reaches 55 degrees Fahrenheit. Depending on the climate you live in, applications could take place in early March and then again in September.

How to Select a Pre-Emergent Herbicide for Weed Control

When selecting a pre-emergent herbicide, there are many different types of products to consider. Carolina Fresh Farms recommends applying the following spring pre-emergents for your grass type anytime between February 21st–March 15th for warm season grasses (zoysia, St. Augustine, bermuda grass, centipede) and March 1st–March 15th for cool season grasses (Fescue):

• Zoysia – Apply a 0-0-7 .38% Prodiamine to prevent summer weeds such as crabgrass
• St. Augustine – Apply a 0-0-7 .38% Prodiamine
• Bermuda – Apply a 0-0-7 .38% Prodiamine
• Centipede – Apply a 0-0-7 .38% Prodiamine
• Fescue – 16-0-8 .38% Barricade 

The 0-0-7 .38% Prodiamine and 16-0-8 .38% Barricade are great products designed to prevent spring and summer weeds such as crabgrass. For more information on spring lawn care for each grass type, visit our Care Page.

Lastly, do not apply a pre-emergent herbicide at this time if you plan on seeding your lawn in the spring. Pre-emergents don’t only prevent weeds from germinating—they’ll prevent grass seeds as well. 

While the process may seem daunting, choosing a pre-emergent herbicide for spring weed control does not need to be as challenging as you may think. Simply taking the time to select a pre-emergent for your lawn may just be the key to keeping your lawn weed-free throughout the entire year. If you have any questions, contact your local Carolina Fresh Farms outlet for more information.