Emerald ash borer in Kansas

Systemic insecticides can keep a still-healthy ash alive. Missouri’s EAB management guide and K-State’s field advice both say the same thing we tell customers: treat before the canopy is shot. Once more than about half the crown is gone, you are paying to delay a removal.

The products that actually move in a tree are applied as a trunk injection, a soil drench, or a basal bark spray. Emamectin benzoate injections are the ones we use on specimen trees we intend to keep for years. Soil products (imidacloprid, dinotefuran) are cheaper and need more frequent return trips. Drought-stressed trees on Johnson County clay do not take soil drenches well unless we water the root zone first.

If the ash is already shedding large limbs, or it sits over a house in Leawood or a storefront in Mission, we price a removal. Dead ash gets brittle faster than people expect. That is how you get a trunk that hinges through a garage door in a July thunderstorm.

Adult beetles do not fly far on their own. They ride firewood, brush piles, and nursery stock. Once a neighborhood has one infested street tree, the rest of the block is on a clock. Overland Park, Prairie Village, and Leawood already spent years and city budgets taking ash out of rights-of-way. Private yards are catching up.

If you are replacing an ash, do not plant another ash. Kansas Forest Service keeps a recommended-tree list for a reason. We would rather put a bur oak, a Kentucky coffeetree, or a bald cypress in that hole than sell you a second round of injections in 12 years.