Vegetation Management: Herbicides

Succession of many wetlands from open-canopy fens to closed-canopy swamps contributes to the loss of bog turtle habitat. Reviewed here are the herbicide application methods described in the US Fish and Wildlife Service Biological Opinion 2010.

Herbicide Application Methods

Injection
This method involves the injection of pellets of glyphosate or imazapyr directly into
the trunks of woody vegetation. Herbicide is delivered directly to woody stems, avoiding any herbicide spillage in the wetland. Little or no migration of herbicide from the root system to wetland soils is anticipated.

Hack and Squirt (also Frill, Drill and Fill)
The trunk of the tree is cut using a sharp object (e.g., knife, saw, ax) or holes are
made in the trunk with a power drill or other device. Glyphosate is then
immediately applied to the cut using a backpack sprayer, squirt bottle or syringe. A
Hypo-Hatchet® Tree Injector can also be used.

Cut Stump (or Cut Stem)
The tree or shrub is cut within 6 inches of the ground, exposing a horizontal
treatment surface. Glyphosate is immediately applied to the cut surface(s) using a
spray bottle or wick applicator. If vegetation has been cut previously (outside the
glyphosate application period), height of the initial cutting should be adjusted to
allow for subsequent re-cutting. A variation of this method is the “snip and drip” technique, which is used to treat Phragmites. This involves cutting the stem and then dripping glyphosate onto the cut stem.

Wick Application
This is a foliar application method, intended to deliver herbicide to the intact leaves
or stem of the target plant.

Spot Spray
This is a foliar application method, intended to deliver herbicide to the leaves and/or
stem of the target plant.

The application methods are consistent with those discussed in The Nature Conservancy’s Weed Control Methods Handbook: Tools & Techniques for Use in Natural Areas (Tu et al. 2001)4 and Safe Herbicide Handling in Natural Areas: A Guide for Land Stewards and Volunteer Stewards (Hillmer and Liedtke 2003)5. Further details about these methods and their applicability can be found in Chapter 5 and on pages 5-13 of the subject publications, respectively.

Weed Control Methods Handbook: Tools and Techniques for Use in Natural Areas

safe herbicide handling in natural areas a guide for land stewards and volunteer stewards

US Fish and Wildlife Service. (2010). Biological Opinion: Effects of the Implementation of Habitat Restoration Practices by the Natural Resources Conservation Service on the Northern Population of the Bog Turtle. Prepared by Region, 5.

- Jason Tesauro, March 2021