Know Your Deer Plants: Horsemint

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There are many plants that deer will rarely consume, if at all, and will only do so when there are few other options available. These plants are typically referred to as “low preference” forages; however, when it comes to your plant identification skills, they should take a high priority.

Why would I choose to profile a plant that deer don’t even like to eat? The fact is that it’s just as important for quality deer managers to be able to identify these plants. One reason for this is that if you observe heavy browsing on low preference forages on your property, it may be a sign that your habitat, in other words the available nutrition, may be holding you back from achieving your deer management goals.

Horsemint is a native herb from the mint family, and it is regularly categorized as a low preference deer forage. In fact, horsemint is often listed on numerous ‘deer-resistant’ gardening books and websites. However, deer will consume it, especially when populations exceed the land’s carrying capacity.

Horsemint occurs as scattered plants or small groups on sandy soils and can be found in prairie habitats, savannas, disturbed areas, forest roads and openings. It is usually a short-lived perennial, with some plants persisting for only one or two years.

All plants from the mint family are easily identified by their square (four-angled in cross-section) stems and their mint- or oregano-scented fragrance, and horsemint is no exception. Horsemint is also an intricate, conspicuous wildflower, and it can grow up to 1 to 3 feet tall. Its stem is typically unbranched, except for a few short, leafy stems that develop from the juncture of the leaves along the main stem. It is also brown to reddish purple in color and densely hairy. The central stem of horsemint also produces two or more dense heads of flowers that can be found stacked at the top of each plant.

So, what do you do if you have horsemint on your property and you find sign of heavy deer browsing? First, start developing a protocol to estimate the relative deer density in the area to determine if you need to increase your future antlerless harvests. You can do this through a variety of population monitoring techniques, and performing a trail-camera survey is an easy option (to learn more, buy QDMA’s new book Deer Cameras: the Science of Scouting). Second, evaluate the available nutrition to deer and other wildlife by performing a comprehensive habitat analysis within at least one square mile around your property. This will allow you to be sure your forests and old fields are providing the most desirable browse items in the right mix of forbs, grasses, shrubs and trees, and that your food plots are producing the maximum tonnage possible. Finally, continue to monitor biological cues in your deer herd, such as annual harvest weights, antler beam diameters, lactation status and others, along with the browsing pressure on horsemint and other low preference forages to help determine if your deer management plan is working.

This article is an excerpt from the “Natural Species Profile,” a regular feature of QDMA’s Quality Whitetails magazine.


About Matt Ross

Matt Ross of Saratoga Springs, New York, is a certified wildlife biologist and licensed forester and QDMA's Assistant Director of Conservation. He received his bachelor's in wildlife conservation from the University of Massachusetts-Amherst, and his master's in wildlife management from the University of New Hampshire. Before joining the QDMA staff, Matt worked for a natural resource consulting firm in southern New Hampshire, and he was a QDMA volunteer and Branch officer. He and his wife Sadie have two daughters, Josephine and Sabrina.