Pyrus calleryana
For Callery pear (Pyrus calleryana), tree-of-heaven (Ailanthus altissima), and other non-native, invasive trees, the cut stump method described above can be used, but it is not practical for large infestations or for large trees. In these situations, basal bark and hack & squirt methods are recommended.
Basal bark treatment: For tree trunks/main stems less than 6 inches in diameter, mix 1 to 5 gallons of 4 to 5% triclopyr (Garlon® 4 – ester formula – is recommended) in enough bark oil to make 100 gallons of spray mixture. Apply with a backpack sprayer or power spraying equipment using low pressure (20 to 40 psi). Spray the basal parts of brush and tree trunks to a height of 12 to 15 inches from the ground, thoroughly wetting the indicated area, but stopping before runoff occurs. Old trees or trees with rough bark require more spray than smooth, young bark. Avoid spraying near water or with snow on the ground.
Hack & squirt: For tree trunks/main stems greater than 6 inches in diameter, use a hatchet deep enough to get into the cambium layer and make one hack per 3 to 4 inches of tree diameter. Squirt herbicide into the cut: a mix of at least 50% triclopyr (Garlon® 3A – amine formulation – is recommended) in water. The more hacks, the greater the probability of killing the tree. Stop squirting before runoff occurs.
Identification and fact sheets
- Learn about Callery pear at Invasive.org
- Learn about Callery pear at Woody Invasives of the Great Lakes
- Read more from the Missouri Department of Conservation about identification, threats, and control practices of Callery pear
- Read MoIP’s guide to effective control of Callery pear
Representative photos of Callery pear:
Callery pear impact, abundance, and trend in Missouri
