10 Best Pre-Emergent Herbicides 2024 in the United States

Maintaining a uniform, healthy lawn is challenging work. The species of grass seed that you’ll choose will largely depend on the climate where you live. For example, Bermuda grass is ideal for a hot, dry climate, but needs sunlight. Fescue grass, on the other hand, needs to be watered often, but can thrive in the shade. But once you’ve chosen one species, you don’t want an invasion from another species. For example, crab grasses can deposit thousands of seeds on your lawn, competing for space and nutrients. You want to eliminate these unwanted grasses before they sprout. That’s where a pre-emergent herbicide comes in.

The trick to pre-emergent weed killers is to focus on unwanted weed growth while leaving the desirable plants alone. They do this by attacking the growth of a plant’s root system. The pre-emergent herbicide will therefore leave more mature plants alone. But, there are still a lot of techniques for getting the correct pre-emergent herbicide, and knowing when to apply it.

We’ll provide some information about pre-emergent herbicides for your lawn or garden. Some are for particular grasses, while others have a broader spectrum that they treat. Let’s look at some lawn care tricks, to outsmart these resilient weeds.

There are three classes of grass species:

• Annuals: These have a life cycle of a year or less. These grasses will be the easiest to treat with a pre-emergent herbicide. Since no root system remains after the growing season, if you attack them before they take root, you won’t have to worry about them until next year.

• Biennials: These have a two-year life cycle. Their leaves grow in a circular pattern close to the ground (called a “rosette”) in their first year, and then a stalk in their second year. The stalk then produces a flower, which deposits seeds. Familiar examples include dandelions and Queen Anne’s Lace.

• Perennials: Perennials are plants that have a life cycle of more than two years. These will be the most resilient since they develop a root system that lasts through all seasons, sprouting every spring. Examples of perennial plants include Zoysia grass, Bermuda grass, and clover. But there are pre-emergent herbicides for perennial plants as well. The Pendulum 2G Herbicide employs pendimethalin to keep weed seeds from growing. Once weeds have grown and taken root, it won’t be as effective.

Pendulum 2G Herbicide

Different species of grass grow better in the summer months, while some grow better in southern states in the winter months. We can distinguish between pre-emergent herbicides by when you apply them:

• For summer annuals: You should apply the pre-emergent herbicide in the early spring, in order to prevent weeds from developing a root system. Crabgrass, goosegrass, and foxtail are familiar summer annuals. A product that’s effective for summer annuals is the Andersons Pro Turf Barricade.

Andersons Pro Turf Barricade

• For winter annuals: The seeds of winter annuals germinate in the late summer/early autumn. Pre-emergent herbicides for winter annuals should therefore be applied in the autumn, to prevent the weeds from developing a root system and sprouting in the winter.

Here are some impressions of people who purchased a pre-emergent herbicide:

• When to reapply: One customer who bought the Pendulum 2G Herbicide said that you have to reapply the substance every time the soil is disturbed. This is because there’s a chance that seeds of unwanted plants went beneath the surface of the soil, and are now in the ideal conditions to sprout. You should also apply it every 3 months.

• Saves you from backbreaking work: These pre-emergent herbicides will not be effective against weeds that already sprouted (“post-emergent control”). For these, you’ll either have to apply a weed killer or rip them out by hand. But, if weeds never sprout, it’ll save you the effort of having to remove them manually.

Here are some features and pointers to consider when purchasing a pre-emergent herbicide:

• Needs water to become active: Many of the products in the Best Reviews Guide list need either rainfall or irrigation to activate the granules. So, whether you apply them in the spring or autumn, make sure that it’s either prior to rain or that you water the ground for the product to start working.

• Application: Take note of the area that each product is able to cover. For example, around 2.3 lbs of the Snapshot 2.5 TG Granular Pre-Emergent Herbicide is capable of treating 1000 square feet of turf, when applied with a rotary spreader. (You may have to apply twice that amount, depending on the target weeds.) Keep track of the turf in the coming weeks after application, to make sure that the application was effective.

• Months of protection: Products will differ in how long they provide protection. The Preen 24-64070 Insect and Weed Preventer protects against weeds from taking root for four months after application. It will also repel ants, fleas, ticks, and other insects.

• Products that are safe around pets and children: Most pre-emergent herbicides are intended to work beneath the surface, penetrating to where the seeds are and preventing growth. Therefore, it’s usually safe for children and pets to walk in the treated areas, once the ground has dried. But, there are also natural weed preventers, such as the Preen Natural Weed Preventer. It uses corn gluten meal, which has a slight herbicidal effect by preventing the formation of roots. It is effective against crabgrass, dandelions, clover, and more. But it has to be applied quite often, at around once per month.

Preen Natural Weed Preventer

 Final Verdict

We looked at the various pre-emergent herbicides. Some are broad-spectrum, able to take care of a variety of perennial weeds. Others are specific for annual plants. If applied regularly, they can spare you a lot of backbreaking work and maintenance later!