The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- Dichlobenil (2,6-dichlorobenzonitrile)
- Chemical class
- Nitrile; WSSA lists nitriles as Group 20 herbicides that inhibit cell wall (cellulose) building.[2][1]
- Mode of action
- WSSA Group 20: Cellulose inhibitors (nitriles)[2]
- Signal word
- Barrier 2% Dichlobenil Granules (also sold as Barrier 2G, Norosac 2G and Dyclomec G-2): Caution[1]
Home fruit and berries
Apple, blueberry, cherry, grape and pear plants established at least 4 months can be treated only from fall after harvest to the following spring. Wait 30 days after application before harvesting cherries.[1]
Blackberries and raspberries get 4.6 pounds per 1,000 sq ft, applied to established plantings before new shoots emerge in spring.[1]
Where it is used
For annual weeds, apply in early spring before weeds emerge and after pulling the existing ones. For perennial weeds, apply between late fall, after a killing frost, and midwinter.[1]
Water the soil to a depth of ¼ to ½ inch after spreading so the herbicide moves into the root zone, without flooding or puddling. Wet bark or wood-chip mulch thoroughly before applying.[1]
Keep granules from lodging in foliage, especially on conifers, or piling against trunks at the soil line. Don't use it on very light sandy soils, slopes, snow or frozen ground.[1]
It isn't for flower gardens, wildflowers, foliage plants or bulbs. Don't seed or transplant into treated soil, and avoid disturbing the soil afterward to keep weed control intact.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Barrier 2% Dichlobenil Granules (also sold as Barrier 2G, Norosac 2G and Dyclomec G-2)[1] | PBI/Gordon Corporation | 2217-678 | 2.0% | granules | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Barrier 2% Dichlobenil Granules (also sold as Barrier 2G, Norosac 2G and Dyclomec G-2) | Soil around established landscape trees and shrubs (planted at least 4 months) | Annual weeds and grasses plus perennials such as Canada thistle, quackgrass, curly dock, horsetail, dandelion and plantain | 4.6–7.0 lb product per 1,000 sq ft[1] 4.6 lb per 1,000 sq ft (3/4 oz per 10 sq ft) for annual weeds; 7.0 lb per 1,000 sq ft (1 1/8 oz per 10 sq ft) for perennial weeds. Rates above this can injure ornamentals. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if swallowed, absorbed through skin or inhaled, and causes moderate eye irritation. Avoid breathing the dust and wear long sleeves, long pants, socks, shoes and waterproof gloves.[1]
Pets
Keep people and pets out of the area while you apply. They can return once the granules are thoroughly watered in and the treated soil has dried.[1]
Bees and pollinators
The label has no direct bee warning, but says the product is toxic to plants and may harm forage and habitat for pollinators next to the treated area.[1]
Fish and water
Keep granules out of storm drains, ditches, gutters and surface water, and sweep strays off pavement. Dichlobenil can reach groundwater where soils are permeable and the water table is shallow.[1]
Common questions
- How much Barrier 2G per 1,000 square feet?
- 4.6 pounds for annual weeds and 7.0 pounds for perennial weeds around ornamentals. With the shaker can, that is ¾ oz or 1⅛ oz per 10 sq ft.[1]
- When should I apply dichlobenil?
- Early spring before weeds sprout for annual weeds, and late fall after a killing frost through midwinter for perennial weeds.[1]
- Can I plant flowers where I used dichlobenil?
- The label says not to seed or transplant into treated areas and not to plant crops it isn't registered on within one year.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Barrier 2% Dichlobenil Granules label, EPA Reg. No. 2217-678 (EPA-stamped, June 26, 2026).” www3.epa.gov/pesticides/chem_search/ppls/002217-00678-20260626.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)