Breaking the Crabgrass Cycle: Fall Seeding with Pre-Emergent Herbicide

Introduction

Northern Des Moines, IA: 99% crabgrass after two Roundup-till-seed cycles (spring/summer). Crabgrass outcompetes everything.

Solution: Fall Seeding + Tupersan

• Timing: Early fall (September)—crabgrass activity low, cool-season grass establishment high.
• Starter Fertilizer with Tupersan (siduron): Only pre-emergent that allows grass seed germination while blocking crabgrass.
• Verify Label: Not all "crabgrass preventer" fertilizers contain Tupersan.

Why Spring Failed

Crabgrass germinates aggressively in spring/summer. Fall gives desirable grass a head start.

Conclusion

Seed in September with Tupersan-containing starter fertilizer. Break the cycle; establish grass before next crabgrass season.