The Proper Tree Injection Technique


Equipment and formulations only get you so far. Proper application is critical for achieving complete, fast distribution and ensuring predictable results when protecting trees. The ISA's Tree Injection Best Management Practices guide highlights root flare application and proper drilling as fundamentals for success. Here are some ways to put that to work for you:

Optimal injection zone: Root Flares

There are several reasons why injecting into the root flare is recommended:

  • Root flares have a greater ability to 'heal' (CODIT) from tree injection wounds versus trunk tissue.
  • The root flare is made up of significantly more active xylem (sapwood). This provides faster uptake and enhanced distribution of the product throughout the trunk and canopy.
  • Sideways movement of product is greater in the root flare than in trunk tissue, resulting in more even crown distribution.

PIGTAILS - Here's a tip: a sharp bit drilled into healthy tissue will make a wood “pigtail”. When you stop making pigtails, change drill bits to ensure you are making clean cuts.

Pro Tips

These guidelines apply regardless of the tree injection device that is used

Go Low Inject into the root flare. Go as low as you can if the flares are not accessible.

Keep It Clean Use a stiff brush to clean dirt and debris off the bark prior to drilling.

Stay Sharp Use only razor-sharp, high-helix drill bits. Replace the bits every 5-10 trees.

Not Too Deep Drilling past the active xylem tissue can cause unnecessary wounding.


WOOD ANATOMY Different species of trees have different tissue structures that can greatly affect uptake. As a general rule, ring porous trees are faster to inject than diffuse porous trees.
SOIL MOISTURE Both drought conditions and water-logged soils can decrease uptake time. In dry conditions, properly irrigate a tree prior to injection for faster uptake.
TREE HEALTH Trees growing in stressful conditions often respond by growing thinner layers of new xylem tissue, which can slow down uptake time.

Tree Injection Team


Nothing beats hands-on training Our team is comprised of Certified Arborists, former small business owners, and training specialists. They are here to get you and your crews up to speed on how to diagnose, sell, and make proper applications. AVAILABLE TRAINING:

  • Diagnosing Tree Health Issues
  • Sales Training for Arborists
  • Application Crew Training
  • Archived Webinars
  • Application Training Videos