Weed Control in New Jersey

Weed control treatments are safe for pets and kids once the product has dried on the grass, which usually takes a few hours. New Jersey requires lawn care companies to post a notification sign after any pesticide application, so homeowners always know when a treatment happened, according to the New Jersey Department of Environmental Protection. Keeping people and animals off the lawn until it's dry is the simplest way to stay safe after a visit. A technician can confirm the specific re-entry time for the product used.

Post-emergent weed treatments usually show visible results within 7 to 14 days, though some tougher broadleaf weeds can take up to three weeks to fully die back. Weeds typically turn brown, curl, or wilt before disappearing, rather than vanishing right away. Pre-emergent treatments work differently — they prevent new seeds from sprouting, so there's nothing visible to see even when the application worked. If weeds are still thriving after three weeks, a follow-up call is worth it rather than waiting it out.

Crabgrass seeds can survive in soil for years, so a single season of treatment rarely eliminates it completely. Mowing height and fertilization affect how much crabgrass takes hold, too: Rutgers Cooperative Extension research shows that mowing at the highest recommended height for a grass type, combined with proper fertilization, builds a denser lawn that crowds out crabgrass more effectively than herbicide alone. Compacted soil and thin, weak turf give weed seeds more room to establish even with pre-emergent treatment in place. Combining consistent pre-emergent applications with the right mowing and fertilization habits over multiple seasons is what actually breaks the cycle.

Most post-emergent weed treatments need a few hours of dry time before watering or mowing, so the product can absorb into the weeds. Watering too soon can wash the treatment off the leaf surface before it's had a chance to work, reducing how well it controls the weeds. Pre-emergent treatments work differently — many actually need to be watered in shortly after application to activate the barrier in the soil. A technician will let you know which type of treatment was applied and how long to wait before watering or mowing.

Pre-emergent weed control should go down in early spring, before soil temperatures reach the mid-50s for several consecutive days — the point at which crabgrass and other summer weeds begin to germinate, per Rutgers Cooperative Extension. Waiting too long into spring lets weed seeds sprout before the herbicide barrier is in place, making it far less effective. Post-emergent treatments for weeds already growing can be applied throughout the season as needed. Starting a program early in spring gives a lawn the best shot at staying weed-free through summer.