Triclopyr basal application (for ailanthus control)

dbooksta · Jun 10, 2017

I've been experimenting with ways to control ailanthus, which is terribly invasive in parts of land I manage. Previously I would hack-and-spray or cut and cover stumps with 7% glyphosate to kill the roots and prevent reemergence. Another arborist, seeing some of the infestation, suggested triclopyr.

Two weeks ago I tried a "basal application:" saturating with 62% triclopyr the bottom 15" circumference of bark on a number of ailanthus trees ranging in diameter from 1" to 12". I had been expecting a more severe response, but only on the smallest trees is there even a hint of wilting at the tips of leaves.

What should I expect from this triclopyr basal application? Based on some reading I was expecting to see much more severe effects in the foliage much faster; but in the end what matters is that it kills the root system.

ATH · Jun 11, 2017

What are you mixing it with. What formulation are you using? (for example: Garlon 3A or Garlon 4)

dbooksta · Jun 12, 2017

Garlon 4, straight undiluted.

ATH · Jun 12, 2017

You need an oil carrier to bring it through the bark. Diesel, kerosene, Alligare basal oil are all examples of products that will work.

Probably need to go higher on the trunk too...from about 3-4' down to the ground.

dbooksta · Jun 13, 2017

Ah ha: I thought because triclopyr itself is so volatile, and mixes only with oils, that it would penetrate on its own. Regardless, I just found this Penn State study which concluded that dilutions of Garlon 4 down to 5% were as effective as "traditional 20-30%" dilutions, so evidently I can save quite a bit of money by diluting with diesel!

This week I'm also noting more crown necrosis in the smaller ailanthus I treated, which is probably thanks to their very thin bark, compounded by recent hot weather.

ATH · Jun 13, 2017

Diesel certain works...but really stinks (literally) to work with in the summer! that is where the purpose-made basal oils are nice. They look expensive, but when you realize you use a lot of water, they aren't so bad. More than diesel though.