Service · Cokato, Minnesota
Emerald Ash Borer Treatment in Central Minnesota
Emerald ash borer treatment protects healthy ash trees around Cokato, Annandale, Hutchinson and the rest of our area from an insect that is now well established across central Minnesota. Treatment works, and it works well, but only on trees that are still in decent shape. The most useful thing we do is tell you which of your ash are worth the money.
How trunk injection works
The product goes directly into the tree's vascular system through small injection ports at the base of the trunk, and the tree distributes it up into the canopy. Larvae feeding under the bark take it in and die, which stops the tunnelling that girdles the tree. Injection is used rather than a soil drench because it puts the product only in the tree, with nothing moving through the soil to anywhere else, which matters near water and where there are pollinators around.
The treatment window and the cycle
Injection is done during the growing season while the tree is actively moving water, which in this part of Minnesota means roughly mid-May into the summer. It cannot be done in the dormant season because the tree will not take the product up. We treat on a two year cycle, and that has to be kept up: a treated ash that gets missed for a few years is back to being an untreated ash, and the insect pressure locally is not going away.
Which ash are worth treating
Canopy is the test. An ash that still has most of its crown will respond well and can be kept indefinitely with ongoing treatment. Once an ash has lost around half its canopy, injection is no longer a sensible investment: the vascular tissue that would carry the product is exactly the tissue the larvae have already destroyed, so the product does not get where it needs to go and the tree does not have the reserves to recover. We will say so when that is the case, because treating a tree that far gone wastes your money and only delays a removal that is going to happen anyway.
- Most of the canopy still present: good candidate, treat and keep
- Noticeable thinning at the top only: treat now, it responds well
- Around half the canopy gone: borderline, and we will talk it through
- More than half gone, trunk sprouts everywhere: removal is the better spend
Deciding on a yard with several ash
Plenty of properties around here have four or five ash and treating all of them does not make sense. The usual approach is to pick the ones worth keeping, meaning the big healthy ones that actually shade the house or the ones that would leave a hole nobody wants, treat those on the cycle, and remove the rest over a couple of seasons. That spreads the cost and gets the failing trees down while they are still straightforward to take.
What you get
- Trunk injection, so nothing moves through the soil
- ISA Certified Arborist assessment before anything gets treated
- Honest read on which ash are worth the investment
- Two year cycle with a reminder when the next treatment is due
- Treatment and removal handled by the same crew for mixed yards
- Replanting advice that avoids repeating the ash monoculture
How the job runs
Where we do this work
Emerald Ash Borer is something we do right across our area, out of the shop in Cokato. The towns we are in most often:
- Emerald Ash Borer in Cokato
- Emerald Ash Borer in Dassel (5 miles from the shop)
- Emerald Ash Borer in Litchfield (17 miles from the shop)
- Emerald Ash Borer in Hutchinson (22 miles from the shop)
- Emerald Ash Borer in Annandale (14 miles from the shop)
- Emerald Ash Borer in Maple Lake (18 miles from the shop)
- Emerald Ash Borer in Howard Lake (7 miles from the shop)
- Emerald Ash Borer in Waverly (12 miles from the shop)