Herbicides are often the best and only solution to problem invasives.

A number of the invasives we discuss lack good management alternatives to herbicides. There are lots of situations that mechanical measures like pulling, burning, or cutting simply can’t solve. Here is our current approach to “better living through chemistry”.

We use herbicides in two contexts, each of which has its own preferred cocktail recipe and application method.

Foliar Application

This is just a fancy term for “spray on the leaves”. This is the approach we take with sericea lespideza and smooth sumac. Here is the mix that we’ve found to be very effective in killing the target species and sparing the rest:

Per one gallon:

  • 2 oz triclopyr ester (brand names: Remedy or Garlon 4)
  • 4 oz 2,4-D amine
  • 1 oz dishwashing soap (surfactant)
  • 1 oz bluing solution (marker)

We find it most convenient in the field to carry these chemicals in self-measuring containers that make it easy to mix up additional gallons accurately. We’re partial to Solo handheld sprayers or backpack sprayers as we find this kind of precision application to be far superior to a boom sprayer. Others use “wick applicators” but we’ve not found a need for anything other than hand sprayers.

Application technique is simple: spray all the leaves of the plant until well-covered but not dripping (much). The big challenge is noting where you’ve been and where you need to go; the bluing marker solution is invaluable here.

Stump Application

Invasive trees that you cut need to be “painted” with a stump herbicide to prevent re-sprouting (other than red cedar, which politely remains dead when cut). Here’s what we use:

This is a version of picloram that doesn’t require a license to purchase and apply. It comes in a convenient squeeze bottle with a pop-up cap. To use it, you simply squirt a bit on the cut stump while evening out the application with an old paint brush. Only the cambrium layers need to be treated. This stuff is brightly blue, too, to make it easy to see where you’ve been.

Created: October 22, 2008 18:50
Last updated: February 02, 2010 00:15


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