The best pre-emergent herbicides are long-lasting, stop a wide variety of weeds, provide additional value with added fertilizer, or are safe for grass seed and seedlings. Rather than choose a product that will wash out of your soil quickly and allow weeds to invade, make sure the product you use is top of the line. With one of these powerful pre-emergents, you can stop weeds from sprouting and protect your lawn.
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What is Pre-Emergent Herbicide?
Pre-emergent herbicide prevents weeds from sprouting in your yard. A pre-emergent product enters the soil and remains there for 1–6 months. During this time, it kills all seeds that germinate. Most pre-emergents are non-selective, meaning they will attack all seed types, including grass, weeds, trees, and other plants.
- After application, pre-emergent remains in the soil for 1–6 months (depending on the product).
- While active, pre-emergent attacks seeds as they germinate underground.
- Pre-emergent does not attack mature plants or dormant seeds.
- Almost all pre-emergent products are non-selective—they will kill every type of weed, grass, and garden plant seed.
- Pre-emergent can be applied in spring, summer, and fall to stop weeds that sprout at these times.
Timing your pre-emergent herbicide application is everything. A spring application will stop crabgrass, and a good herbicide will even last long enough to also stop summer annuals from cropping up. A fall application of pre-emergent will stop winter annuals, such as Poa Annua.
Top 5 Pre-Emergent Herbicides for Your Lawn
In a market full of products that promise miracles, there are some real standouts that deliver more than the competition has to offer. Below are pre-emergents that truly deliver unique results. Whether you want your pre-emergent to last as long as possible, control specific weed species extremely well, or a pre-emergent that won’t attack new grass seed, there’s a solution for you.
Longest-Lasting Pre-Emergent: Barricade
Barricade is our top choice for a reliable, long-lasting pre-emergent. A single application remains active for 6 months in your yard. This is 2–3 times the duration of average pre-emergents. A single spring application will stop spring weeds and protect from summer annuals until fall. A second application in the fall provides year-round weed protection.
- Active in the soil for 6 months.
- Great for regions with long growing seasons.
- Spring application stops both spring weeds and summer annuals.
Barricade’s 6-month in-soil activity is ideal. By the time your spring application wears off, you can decide whether to overseed your lawn in fall or apply a second round of pre-emergent. For reliable, long-lasting weed-stopping power, Barricade is the best choice
Grass Seed Friendly Pre-Emergent: Tenacity
If you’ve used pre-emergent in the past, you’re probably familiar with the rule of thumb that seeding grass and spreading pre-emergent don’t mix. Pre-emergents typically kill grass seed, so you have to wait until your pre-emergent wears off before seeding your lawn. However, there is an exception to this rule. Tenacity works as a pre-emergent that will kill weeds as they sprout, but won’t interfere with grass seed.
- The only pre-emergent that stops weeds without harming grass seeds and seedlings.
- Tenacity can be applied before seeding grass, or after seed has been spread.
- Remains active in the soil for 30 days.
- Works as both post-emergent (kills existing weeds) and pre-emergent (kills new weeds as they sprout).
- Safe for all turf grass seed mixes that contain less than 20% (by weight) Fine or Hard Fescue.
Tenacity works to kill weeds without harming grass because it was primarily designed as a grass-safe post-emergent herbicide. It targets common broadleaf weeds, perennial weeds, and grassy weeds. However, it lingers in the soil for 30 days. During this time, it kills any weeds that sprout. Although it doesn’t last as long as competitor pre-emergents, Tenacity is the only pre-emergent formula that won’t kill your grass seed. Whether you’re overseeding in spring or fall, use Tenacity to stop weed seeds from sprouting along with grass.
Best Pre-Emergent and Fertilizer Combo: Scotts Turf Builder
Scotts Turf Builder Halts Crabgrass Preventer is an excellent combo product combining pre-emergent weed control with lawn fertilizer. Rather than purchasing multiple products and performing separate applications, save yourself time and money by applying a combination pre-emergent/fertilizer to your grass. This product works great because the best times to apply pre-emergent (early spring, early summer, and fall) are also great times to fertilize your lawn.
- Combines pre-emergent herbicide with fertilizer.
- Save time and money by applying pre-emergent and fertilizer together.
- The pre-emergent active ingredient in Scotts remains effective in the soil for 2–4 months following application.
Although this product is billed as a crabgrass preventer, pendimethalin, the active ingredient in Scotts Turf Builder, is a broad-spectrum pre-emergent that stops all seeds from sprouting during the 2–4 months it is active in the soil.
Best-Pre-Emergent for Gardens: Preen
Preen does for gardens what Scotts does for lawns—prevents weeds and feeds your plants. The difference is that while Scotts is meant to stop weeds while promoting healthy grass, Preen includes a specially formulated fertilizer for flowers, vegetables, trees, and shrubs. It’s important to note that Preen and Scotts can’t be used interchangeably—grass and garden plants have very different fertilizer needs.
- Designed to prevent all types of weeds in gardens at the same time it fertilizes ornamentals, vegetables, and trees.
- Lasts 2–3 months after application.
- Use for gardens, shrubs, and trees only.
With 2–3 months of activity in the ground, Preen has average longevity as a pre-emergent. For long-lasting weed suppression in garden areas, use a non-fertilizer pre-emergent such as Barricade. Any garden fertilizer will have to be applied separately.
Best Crabgrass Control: Pendulum 2G
If your yard is consistently attacked by annual grasses such as crabgrass and poa annua (annual bluegrass), then Pendulum 2G is the answer. It performs extremely well when used to stop grassy weeds, although it is also effective at stopping broadleaf weed species from sprouting.
- Best in class effectiveness at preventing crabgrass and poa annua.
- 3-month active window after application.
- Safe for use on grass, trees, shrubs, and garden plants.
In addition to yard applications, Pendulum is also a great all-purpose pre-emergent. Whether you’re spreading it in your garden or on your turf grass lawn, it will attack seeds as they sprout without harming your established plants.
What is the Best Pre-Emergent Weed Killer?
The best pre-emergent depends on your circumstances and what you need it for. Depending on your goal, the best pre-emergents available today are:
- Barricade: Longest-lasting pre-emergent.
- Tenacity: Pre-emergent that is safe for use when seeding grass.
- Scotts Turf Builder Halts Crabgrass Preventer: Pre-emergent with high-quality lawn fertilizer.
- Preen: Pre-emergent with garden fertilizer.
- Pendulum 2G: Best at stopping invasive grasses, such as crabgrass and poa annua.
Depending on what weed seeds you want to target the most, or if you have specialized needs such as a grass seed safe pre-emergent, the products above are the best in class for each category. These pre-emergents will provide weed prevention power at the best value for your dollar.