Tall Fescue Pre-Emergent Program
Split application in spring: first app BEFORE soil temps hit 55°F at 4-inch depth. A second app 8-10 weeks later extends the barrier through summer. Fall pre-emergent targets Poa annua (annual bluegrass) — apply in September. CRITICAL CONFLICT: if you are overseeding in fall, DO NOT apply pre-emergent in the overseed areas — it will prevent your fescue seed from germinating too. You must choose: overseed OR fall pre-emergent in any given area. Plan your lawn in zones: overseed thin areas, apply fall pre-emergent to thick established areas. Prodiamine and dithiopyr are the most effective active ingredients for fescue lawns.
Frequently Asked Questions
When should I apply spring pre-emergent to fescue?
Apply before soil temps reach 55°F at 4-inch depth. A split application — half rate in early spring, second half 6-8 weeks later — extends the barrier through the crabgrass germination window.
Can I use pre-emergent and overseed fescue at the same time?
No. Pre-emergent blocks all seed germination including grass seed. Skip pre-emergent in areas you plan to overseed. Or use Tenacity (mesotrione), which is safe for fescue seedlings.
Do I need fall pre-emergent for fescue?
Only if Poa annua (annual bluegrass) is a problem. Apply in early September before soil drops below 70°F. But if you're overseeding, skip the pre-emergent in those areas.
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