Tree of Heaven (Ailanthus) Control: Herbicides and Persistence

Father spends heavily on Crossbow+diesel to kill ailanthus ("paradise tree"). Son wants him to stop—it's futile. Asks for prettier management.

Reality Check

Ailanthus is a prolific seeder (325,000 seeds/year), allelopathic (toxins suppress other plants), and root-sprouts aggressively. Eradication requires years of integrated effort.

Effective Methods

• Seedlings: Hand-pull after rain (remove all roots).
• Saplings/large: Cut + immediate stump herbicide (glyphosate or triclopyr).
• Foliar spray: 2% glyphosate or 1.5% triclopyr + surfactant (full leaf).
• Basal bark: 25% triclopyr + 75% oil on lower 12–15″.
• Injection: Summer, cuts into sapwood, herbicide in each cut.
• Girdling: Spring, 2–3 cm bark ring + herbicide.

Key

Persistence: treat repeatedly for years. Prevent seed production. "Prettier" isn't realistic—this is a battle, not landscaping.