📈 How to Use GDD
GDD tracks heat accumulation from March 1st. Plants and pests develop on heat, not calendar dates.
- 150-200 GDD: Crabgrass germinates (forsythia blooms)
- 700-1000 GDD: Apply preventive grub control
- 1200+ GDD: Curative grub window opens
💡 Use GDD to time applications - more accurate than calendar dates!