The Wedgle Direct-Inject Tree Treatment System was recently highlighted as the only injection application method using a liquid injection that did not require a drilled hole. Tree trunk injections to deliver nutrients and insecticides are beneficial but can seriously injure a tree if they are given improperly according to “Modern Arboriculture” reference text.
“Arborists and consumers should avoid using a trunk injection method that involves drilling holes in the tree as part of the application process,” said Chip Doolittle, president of ArborSystems in Omaha, NE. The Wedgle Direct-Inject Tree Treatment System was highlighted in the Integrated Pest Management (IPM) of Midwest Landscapes manual as the only injection application method using a liquid injection that did not require a drilled hole. Their system uses a needle-like injection tip that is pushed through the bark.
“Our injection system protects the tree’s health and prevents long-term wounding. Drilled injection holes can permanently damaging a tree’s ability to move nutrients and repeated drilling can seriously harm a tree’s long term health. Multiple and annual treatments can be made with our system without injuring the tree,” said Doolittle.
Injections should be applied beneath the bark and into the tree’s water conducting system in the outermost ring. “Small, shallow holes, no deeper than two growth rings, cause the least amount of injury” according to “Modern Arboriculture,” Alex Shigo’s reference text that is recommended by the International Society of Arboriculture for arborists, landscape architects, urban foresters, fruit growers and students. Shigo was a leader in arboriculture research and study.
Shallow injections allow the insecticide to move upward with the flow of sap through the vascular system. “Wedgle” Direct-Inject Tree Treatment System is designed to distribute the chemical into this outer active layer of the tree. Injection methods that use drilling can be ineffective and cause serious long term damage if the drilled holes are too deep. If the hole is too deep, the pressure of the injection will push some of the insecticide into the inner rings where it will stay and not be used.
“Deep injection holes into trees that form tyloses makes no sense,” according to “Modern Arboriculture.” Tyloses is a sap like compound that forms in response to wounding and plug the damaged growth rings so they can no longer conduct water and nutrients. Holes drilled according to specifications also can cause problems by allowing air into the vascular system which can disrupt water and nutrient movement and provide entry points for pests and disease.
“It’s important to understand the critical difference in the two types of trunk injections,” said Doolittle. “The no-drill method is similar to getting a small cut that mends quickly versus drilling which is comparable to a cut that requires stitches. Some companies compare the trunk injections using drilling to a hospital IV or blood stream injection. But these methods can be prone to infections and need time to heal versus non-drilling which is more like a simple vaccine or shot that heals fast.”