The Best Pre-Emergent for Lawns

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A pre-emergent is the one lawn product where timing is everything. Put it down a few weeks late and you’ve paid for a bag that does almost nothing. Put it down on time and you can skip most of a summer of crabgrass fights.

The active ingredient matters more than the brand name. Most home pre-emergents use one of three: prodiamine, dithiopyr or pendimethalin. The picks below are based on the makers’ published labels and specs and on owner reviews. Timing comes from university extension services. I look after my own lawn, and this is the product I’d least want to get wrong.

The picks

The three active ingredients

NDSU Extension and Texas A&M AgriLife Extension both list prodiamine, dithiopyr and pendimethalin as the standard crabgrass preventers for established lawns.

Nebraska Extension adds that prodiamine and pendimethalin can control one-leaf crabgrass if watered in immediately, while dithiopyr at the full label rate kills seedlings before they tiller.

1. Yard Mastery 0-0-7 Granular Prodiamine: best overall

This is a granular prodiamine product at 0.37% active ingredient on a 0-0-7 carrier, per the product page. The 18 lb bag covers up to 6,000 sq ft and the 45 lb bag up to 15,000 sq ft. The label calls for a minimum of 2 lb and a recommended 3 lb per 1,000 sq ft.

The page says each application gives about 3 months of control, and recommends two spring applications for crabgrass on both cool- and warm-season lawns. Apply when soil is between 55 and 70°F, to a dry lawn, and water in with 1/2 inch within 48 hours.

The label lists yearly maximums by grass. Tall fescue and most warm-season grasses (bermuda, zoysia, St. Augustine, centipede, bahia) go up to 9 lb per 1,000 sq ft per year. Kentucky bluegrass and perennial ryegrass max out at 6 lb, and creeping red fescue at 4.5 lb.

Why it’s the pick:

• Prodiamine gives the longest prevention of the three.
• Granular, so it goes through a normal spreader.
• No nitrogen, so it suits warm-season lawns that aren’t green yet.
• Clear per-grass yearly limits on the label.

What to watch: it does nothing to crabgrass that’s already sprouted. It stops grass seed too, so no seeding while it’s active. It doesn’t ship to Alaska, Hawaii or Maine.

2. Yard Mastery 0-0-7 Dimension (Dithiopyr): best if you’re late

This is a granular dithiopyr product at 0.19% on a 0-0-7 carrier, sold under the Dimension name, per the product page. Bag sizes and coverage match the prodiamine version: 18 lb for up to 6,000 sq ft and 45 lb for up to 15,000 sq ft. The page lists 3 to 4 months of control at 3 to 4 lb per 1,000 sq ft.

The big advantage of dithiopyr is early post-emergent activity. NDSU says it controls crabgrass seedlings up to the three-leaf stage, and K-State says it controls crabgrass up to one tiller. If a warm week caught you off guard and you see tiny crabgrass, dithiopyr can still save the season.

The page lists it for Kentucky bluegrass, tall fescue, ryegrass, bermuda, St. Augustine, zoysia, centipede and bahia.

Why it’s a good choice:

• Forgiving if you miss the ideal window.
• Works on both cool- and warm-season lawns.
• Also useful as a fall application, as the seller notes.

What to watch: the product page itself doesn’t spell out the early post-emergent claim, so check the bag label for leaf-stage limits. It doesn’t ship to Alaska, California, Hawaii or Maine. No seeding while it’s active.

3. Scotts Turf Builder Halts Crabgrass Preventer with Lawn Food: easiest to find

Halts combines pendimethalin (1.29%) with a 30-0-4 fertilizer. A 13.35 lb bag covers 5,000 sq ft, per Scotts’ 4-bag program page, which lists the Halts label details. Scotts says to apply in early spring, before the third or fourth mowing.

The label instructions are specific:

• Water with 1/4 to 1/2 inch of rain or irrigation within 2 to 3 days.
• No more than two applications per year.
• Don’t seed or sod for 4 months after applying.
• Don’t use on dichondra or bentgrass lawns.

Why it’s a good choice:

• Sold almost everywhere lawn products are.
• Feeds and prevents in one pass on northern lawns.
• Clear spreader settings on the bag.

What to watch: the nitrogen makes it a northern-lawn product. AgriLife Extension says Texas lawns should use preventers without nitrogen, because warm-season grass is mostly dormant when crabgrass sprouts. Combining fertilizer and preventer also ties your feeding schedule to crabgrass timing.

4. Jonathan Green Veri-Green Crabgrass Preventer plus Lawn Fertilizer: dithiopyr with fertilizer

Jonathan Green’s spring product pairs dithiopyr (Dimension) with a 20-0-3 fertilizer that’s 25% slow-release, per Jonathan Green. The 15 lb bag covers up to 5,000 sq ft and the 48 lb bag up to 15,000 sq ft.

Jonathan Green says to apply in spring before crabgrass germinates, when air temperatures are 50 to 75°F, and to water thoroughly afterward. The page says it gives post-emergent control for up to four weeks after germination, but only on crabgrass up to the three-leaf stage. It’s labeled for one spring application, with a second 30 days later for severe infestations.

Why it’s a good choice:

• Dithiopyr’s early post-emergent action.
• Lower nitrogen and some slow release make it a gentler spring feeding.
• Large bag option.

What to watch: the page gives two different seeding waits (90 days and 3 to 4 months), so plan on the longer one. It says to keep people and pets off the treated area for at least 24 hours and until the grass is dry. Like Halts, the nitrogen makes it a better fit for northern lawns.

5. Scotts Turf Builder Triple Action: if you also have broadleaf weeds

Triple Action combines pendimethalin with 2,4-D and dicamba for dandelions and other broadleaf weeds, plus a 25-0-2 fertilizer, per Scotts. One bag covers 4,000 sq ft. Scotts says to apply in spring when daytime temperatures are consistently 60 to 80°F.

The label has more rules than a plain preventer. Apply to a wet lawn, wait 24 hours before watering in, and don’t apply if rain is expected within 24 hours. Use no more than twice a year with at least 2 months between applications. Wait 4 months before seeding, sodding or aerating.

Why it’s a good choice:

• One product for crabgrass prevention and existing broadleaf weeds.
• Saves a separate weed and feed pass.

What to watch: not for St. Augustine (including Floratam), dichondra, lippia, carpetgrass or bentgrass. The broadleaf herbicides need to stick to wet leaves, so application is fussier. Keep it away from flowers, shrubs and vegetables.

When to apply

Pre-emergents work by killing seedlings as they sprout, so they must be in place first.

Spring. The trigger most extension services use is soil temperature near 55°F. NDSU says to apply before 2-inch soil averages 55°F for three to five days. Nebraska uses 55°F at 4 inches. Missouri Extension says pre-emergents work best when 1-inch soil is 50 to 55°F for five days in a row.

K-State gives Kansas target dates of April 1 in the southeast, April 15 for most of the state and May 1 in the northwest. In the South, crabgrass can start in late winter. Use a soil thermometer to be sure.

Not too early. Nebraska Extension notes that herbicide breakdown by light and soil microbes starts right away, so a very early application has less left at peak germination.

Split applications. Missouri Extension says splitting the label amount into two applications 30 to 45 days apart gives longer control than one full dose. Nebraska recommends a second application around mid-June for season-long control. Both prodiamine products above recommend two spring applications. Stay within the label’s yearly maximum.

Fall. In warm-season areas, a fall application targets winter weeds like annual bluegrass. Both Yard Mastery products list fall use when soil is 55 to 70°F. Don’t apply in fall if you’re overseeding.

More detail on the whole process is in how to get rid of crabgrass.

How to apply a granular pre-emergent

1. Read the label for your grass type, rate and spreader setting.
2. Measure your lawn so you buy the right amount.
3. Apply evenly with a broadcast spreader. A good lawn spreader matters here, because gaps leave crabgrass strips.
4. Sweep granules off hard surfaces. Some products stain concrete.
5. Water in as the label says. NDSU says about 1/2 inch of water moves the herbicide into the soil.
6. Don’t aerate or dethatch afterward. It breaks the treated layer.

Pre-emergent and grass seed

Most pre-emergents also stop grass seed. NDSU says standard preventers shouldn’t be used on new seedings, and AgriLife Extension says not to apply them if you plan to seed or sod, or on turf established within the past year, unless the label allows it.

So pick a season:

• Seeding in fall? Use a spring pre-emergent as normal. By fall, most labels allow seeding. Check the waiting period on your product.
• Seeding in spring? Skip the standard pre-emergent. NDSU and Nebraska Extension point to siduron and mesotrione products for new seedings.

The full process is in how to overseed a lawn. For grass seed picks, see best grass seed.

Granular vs. liquid prodiamine

Prodiamine is also sold as a 65% water-dispersible granule (often called Prodiamine 65 WDG, a generic of Barricade) that you mix with water. One product page lists a 5 lb bottle as covering about 4 to 5 acres, and says to use a pump sprayer rather than a hose-end sprayer. It’s much cheaper per square foot, but you need to weigh small amounts accurately and spray evenly. For most homeowners, granular is simpler.

Which pre-emergent should you buy?

Fertilizer timing for the rest of the year is in when to fertilize your lawn, and the lawn care calendar puts everything in order.

My pick

For most lawns, a granular prodiamine product like Yard Mastery 0-0-7 Prodiamine, split into two spring applications, gives the longest crabgrass protection. If you tend to miss the window, dithiopyr is more forgiving. For a one-stop store purchase on a northern lawn, Scotts Halts works. Whatever you buy, apply before soil holds at 55°F, water it in, and follow the label.