The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Pendimethalin (CAS 40487-42-1)
- Chemical class
- Dinitroaniline; WSSA Group 3 microtubule assembly inhibitors.[2]
- Mode of action
- WSSA Group 3: Microtubule assembly inhibitors (dinitroanilines)[2]
- Signal word
- Scotts Turf Builder Plus Halts for Lawns: Caution[1]
Seeding and sodding limits
Because it stops seeds from sprouting, grass seed is blocked too: don't seed or sod for 4 months after applying it. On new lawns, wait until after the fourth mowing of seeded or sodded areas, and 5 months on newly sprigged areas.[1]
Fall use
An August or September application prevents Poa annua (annual bluegrass) and chickweed from germinating; outside California, a fall application also helps keep moss from establishing over winter.[1]
Where it is used
Apply in early spring before the third or fourth mowing, or before temperatures are regularly in the 80s; a common cue is before dandelions reach the puffball stage.[1]
Apply to a dry lawn. Watering in isn't required, but ¼ to ½ inch of rain or irrigation within 2 to 3 days gives the best results.[1]
It only stops crabgrass in its early stages and won't control mature crabgrass.[1]
Don't rake or aerate for 4 months, which disturbs the treated soil layer.[1]
The granules can stain concrete, stone, cars and shoes; brush them off hard surfaces.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Scotts Turf Builder Plus Halts for Lawns[1] | The Scotts Company | 538-190 | 1.29% | granular fertilizer plus herbicide | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Scotts Turf Builder Plus Halts for Lawns | Established lawns (not dichondra or bentgrass) | Crabgrass, foxtail, barnyardgrass, fall panicum, spurge, oxalis; Poa annua and chickweed with late-summer application | 2.67 lb product per 1,000 sq ft[1] That's the regular rate of 1.5 lb pendimethalin per acre, for cool-season grasses. Bermudagrass, St. Augustinegrass, bahiagrass and centipedegrass take the heavy rate (1.67 lb per acre). Apply no more than twice a year. |
How to apply it, step by step
1. Protective gear
- The label lists no protective gear: it is harmful if absorbed through the skin and causes moderate eye irritation, so keep it off your skin and out of your eyes.[1]
- Wash your hands before eating, drinking or using the toilet, and if granules get inside your clothes, take them off, wash and change.[1]
2. Before you spray
- It prevents crabgrass and other listed weed seeds from sprouting; it does not kill crabgrass that is already growing or other existing weeds.[1]
- Don't use it on dichondra or bentgrass lawns, on newly seeded or sodded areas before their fourth mowing, or on newly sprigged areas within 5 months.[1]
- It also stops grass seed from sprouting: don't seed or sod for 4 months after applying it.[1]
- Apply it when the lawn is dry, in calm weather when no rain is forecast for 24 hours; it is toxic to fish.[1]
3. Mixing
- No mixing: the granules go on with a lawn spreader set to the setting printed on the bag (the label lists settings for Scotts broadcast, rotary and drop spreaders; others are approximate). The package rate is 2.67 lb of product per 1,000 sq ft.[1]
4. Applying
- For crabgrass, foxtail, barnyardgrass, spurge and oxalis, apply in early spring: before dandelions reach the puffball stage, before the third or fourth mowing, and before temperatures regularly reach the 80s (before March in southern California, mid-March in northern California).[1]
- Walk at a steady pace with slightly overlapping passes: line up a drop spreader's hopper arrow with the previous wheel track, or space rotary passes about 5 feet from the last wheel track.[1]
- For Poa annua and chickweed, apply in August or September; in mossy areas such as the Pacific Northwest, a fall application helps keep moss out.[1]
- Don't apply it more than twice a year, and allow at least 4 months between applications except for a repeat treatment 6 to 8 weeks later on heavy spurge.[1]
5. After you spray
- Keep people and pets off the lawn until the dust has settled.[1]
- You don't have to water it in, but ¼ to ½ inch of rain or watering within 2 to 3 days gives the best results; rain, snow or freezing weather won't hurt it.[1]
- Don't rake or aerate for 4 months, which would break up the treated soil layer.[1]
- Sweep granules off driveways, sidewalks and streets back onto the lawn; they can stain cement, stone, metal, clothing and shoes, so brush them off promptly.[1]
First aid
- In the eyes, rinse slowly and gently with water for 15 to 20 minutes, removing contact lenses after the first 5 minutes; on skin or clothing, take off contaminated clothing and rinse for 15 to 20 minutes.[1]
- If swallowed, call a poison control center or doctor right away, have the person sip water if they can swallow, and don't induce vomiting unless told to; if inhaled, move the person to fresh air and call 911 if they aren't breathing.[1]
Storage, spills and disposal
- Store it in a clean, dry place, with an opened bag folded down and sealed.[1]
- Collect spills to use or dispose of properly. Put an empty bag in the trash or recycling; for a partly full one, call your local solid waste agency, and never put product down a drain.[1]
From the safety data sheet
- The product is a granular fertilizer with 1.29 percent pendimethalin, and the sheet carries the signal word Caution: harmful if absorbed through the skin and moderately irritating to the eyes.[3]
- If it gets in the eyes, hold the eye open and rinse slowly and gently with water for 15 to 20 minutes, removing contact lenses after the first 5 minutes, and call a poison control center or doctor.[3]
- Breathing the dust may irritate the airways and can aggravate asthma, and the granules may irritate the skin of susceptible people.[3]
- Sweep or vacuum up spilled granules, reuse clean material as directed on the label, and keep the product out of drains.[3]
- Keep containers tightly closed in a dry, cool, well-ventilated place.[3]
Safety and environmental hazards
People
Signal word CAUTION: harmful if absorbed through the skin and causes moderate eye irritation. Wash hands after use, and stay off the area until the dust has settled.[1]
Pets
Keep people and pets out of the area during application, and don't apply it in a way that contacts a person or pet.[1]
Bees and pollinators
The label's environmental statement concerns fish and water, not bees; it is applied as granules to turf, not sprayed on blooms.[1]
Fish and water
Toxic to fish. Keep it out of storm drains, ditches, gutters and surface water, sweep granules off pavement back onto the lawn, and apply when no rain is forecast for 24 hours.[1]
Common questions
- Can I overseed after using a crabgrass preventer with pendimethalin?
- Not for 4 months. The label says the active ingredient in the soil will prevent grass seed from sprouting.[1]
- Does pendimethalin kill crabgrass that's already up?
- No. The label says it controls crabgrass only in its early stages and does not control mature crabgrass.[1]
- Do I need to water it in?
- It isn't required, but ¼ to ½ inch of water within 2 to 3 days of application gives best results.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Scotts Turf Builder Plus Halts for Lawns label, EPA Reg. No. 538-190 (EPA-stamped, Feb. 22, 2023).” www3.epa.gov/pesticides/chem_search/ppls/000538-00190-20230222.pdf (accessed 2026-10-06)
- Weed Science Society of America, “Summary of Herbicide Mechanism of Action According to the Weed Science Society of America.” wssa.net/wp-content/uploads/WSSA-Mechanism-of-Action.pdf (accessed 2026-10-06)
- The Scotts Company LLC, “Scotts Turf Builder with Halts Crabgrass Preventer 30-0-4 Material Safety Data Sheet (The Scotts Company, revision 0, January 17, 2008; EPA Reg. No. 538-190, the label on this page; copy hosted on The Home Depot's product-document server).” images.homedepot-static.com/catalog/pdfImages/f4/f485b457-6c17-4585-a3aa-3e8be13082da.pdf (accessed 2026-10-17)