A DIY tree injection kit is designed for a homeowner to treat a tree with a systemic insecticide, one the tree absorbs and carries through its own tissues, while a professional trunk injection is done by a licensed applicator who can use some insecticides homeowners cannot. Both place the treatment inside the tree, so the choice depends on the product the tree needs and the tree's condition.

How does trunk injection protect a tree?

By placing the treatment into the xylem, the tissue that carries water up the trunk, so it travels inside the tree to where pests feed. Because the product stays within the tree, exposure for the surrounding soil, water, air, and wildlife is reduced.

When does a tree need a professional injection instead?

When the right insecticide is one homeowners cannot apply, or when the tree is already in decline. Some insecticides used against emerald ash borer must be applied by licensed applicators, and an arborist can judge whether a damaged tree is still a good candidate for treatment at all.

How is a DIY trunk injection done?

By drilling half inch deep holes every 4 to 6 inches around the root flare, the point where the trunk widens at ground level, and placing insecticide into each hole. Filling those holes from the syringe in the Multi Insect Killer Tree Injection Kit in early spring, before insects become active, gives a full season of control, and results can start to show within two weeks.

The guide to bronze birch borer in birch shows how a DIY trunk injection reaches an active infestation.

Frequently Asked Questions

How many trees can one DIY injection kit treat?

Up to fifteen small ones. The kit holds enough insecticide for 15 application sites, from fifteen trees 4 inches around to one tree 60 inches around.

Can a DIY injection be done in summer?

Yes. Treatment with the kit can be carried out anytime during the growing season, though treatments earlier in the season are more successful.

How often can the same tree be drilled for the DIY kit?

Once a year at most. Holes should also not be drilled in the same tree in more than two consecutive years.

Does the DIY kit work on pine and other conifers?

Not reliably. Injections into conifers may be slow to take up or not taken up at all.

Will an injection save a heavily infested ash?

Not always. Emerald ash borer damage can keep increasing even with insecticide treatment.