When to apply crabgrass preventer in New Jersey?
By LawnYear editorial team · Published · Updated Windows are read from the extension publications listed under Sources; the dates are approximate.
The answer
Preemergent weed control for Kentucky bluegrass in New Jersey runs from Apr 1 to Apr 30 and from Jun 1 to Jun 15, per Rutgers Cooperative Extension (NJAES), 2019. Apply preemergent herbicide before crabgrass germinates, which is mid to late April in central and northern New Jersey and early to mid April in the south; Rutgers says to apply as soon as forsythia is in full bloom. The whole of April is this site's reading. In areas with severe infestations or sandy soils, a second preemergent application in early June is suggested for some products (shown as June 1 to 15, this site's reading).
Full calendar: New Jersey lawn care calendar · Kentucky bluegrass in other states · Lawn schedule by ZIP
Approximate dates for your state. Check with your local cooperative extension office before you act.
All New Jersey windows for Kentucky bluegrass
The New Jersey calendar on this site lists seeding Aug 15 to Oct 10, fertilizing Aug 15 to Sep 30 and Nov 1 to Nov 30 and weed control Apr 1 to Apr 30 and Jun 1 to Jun 15 for Kentucky bluegrass.
Where the dates come from
Rutgers Cooperative Extension (NJAES): FS1308, Crabgrass Control in Lawns for Homeowners in the Northern US (2019); preemergent timing in New Jersey. Read on 2026-10-30.
What to check for New Jersey
The weed control dates for Kentucky bluegrass above (Apr 1 to Apr 30 and Jun 1 to Jun 15) apply to New Jersey as a whole, so the north and south of the state are not told apart.
Other grasses in New Jersey
For tall fescue, fine fescue and perennial ryegrass, the New Jersey calendar gives Apr 1 to Apr 30 and Jun 1 to Jun 15 for weed control.
Weed control Kentucky bluegrass in other states
- Virginia: Mar 1 to Apr 30 and Aug 15 to Sep 15, per Virginia Cooperative Extension (Virginia Tech), 2025.
- Pennsylvania: Mar 15 to May 15, per Penn State Extension.
- Ohio: Apr 1 to Apr 25, per Ohio State University Extension, Lake County (2007).
- Kentucky: Apr 1 to Apr 30, per University of Kentucky Cooperative Extension Service (2014).
- Indiana: Apr 1 to Apr 30 and Oct 1 to Oct 31, per Purdue University Cooperative Extension Service (1998).