Killing a Large Pine Tree: Girdling Works, Drilling Doesn't

Why Drilling + Roundup Fails

Living tissue (cambium) is just under the bark. Drilling into dead heartwood and filling with herbicide misses the vascular system entirely.

Effective Method: Frill/Girdle Treatment

1. Cut through bark all around trunk (1–2 inch wide strip) down to wood.
2. Leave bottom bark flap attached ("frill") to hold herbicide.
3. Apply concentrated glyphosate (Roundup) immediately to the cut cambium.

Expected Timeline

• Needles turn red/brown within 1 week.
• Full mortality in 2–4 weeks.

Post-Kill Consideration

A 60-foot standing dead pine is a hazard. Plan for professional removal unless it's in a natural area where falling poses no risk.

Safety Note

Follow all herbicide label directions. Wear protective gear. Avoid runoff to water sources.