Spectracide, an herbicide designed for lawns, kills weeds at the roots, saving you hours of weeding. New lawns started from turf or seed, however, are sensitive to chemicals. You can still use Spectracide to get rid of weeds as long as you dilute the formula. Put it on too strong and you could damage your new lawn.
Apply Spectracide in spring or fall to get the best results. Pick a dry day between 45 and 85 degrees Fahrenheit. If it’s too hot, you could end up damaging a new or established lawn. Use a pressure sprayer to apply the herbicide. For a 500-square-foot lawn area, mix 5 tablespoons of the liquid herbicide with 1 gallon of water. This dilution represents half the recommended application amount and is suitable for newly established lawns. Spray the liquid mixture evenly over the lawn area.
New Lawn Establishment
Spectracide is a postemergent weed killer. Postemergent herbicides are designed to kill weeds after they emerge from the soil. Herbicides also come in pre-emergent formulas designed for use on plants before they actually sprout. You can use Spectracide to cover a complete lawn area when weeds are severe. For minor weed problems, use it directly of the areas that need treatment.
After seeding a new lawn, wait until you’ve mowed four times before using Spectracide weed killer. With lawns established from turf, you can use Spectracide after the third mowing session. New lawns require regular mowing as they grow. The specific height for lawn grass (Poaceae) varies by species, but 2 to 3 inches is common. Mow new lawns each time they grow one and a half times taller than the optimum height, each time removing one-third of the total height.
You can use Spectracide on perennial ryegrass (Lolium perenne), thriving in U.S. Department of Agriculture plant hardiness zones 3 through 10, and Bermudagrass (Cynodon spp.), hardy in USDA zones 7 through 10. When using Spectracide on Bermudagrass, expect the lawn to yellow slightly for a day or two after applying it.
“If there is a pre-emergent in it, will the core aeration nullify this effect and allow me to successfully overseed?”
No. This isn’t interfering with germination by blocking the seeds from getting established. It’s killing the new grass that isn’t established well enough to withstand the weed killers. Don’t apply it after the seed germinates, either, until you’ve mowed the new grass at least three times (preferably four times).
“I read the instructions and it says not to seed for 4 weeks after applying. “
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Dicamba, dimethylamine salt. 0.43%
“Do you think I can apply this stuff and safely do an overseed in a week or 2?”
Thanks for the help!