Can Deer Handle The Heat?

While images of bambi are all warm and fuzzy, the damage that deer can accomplish quickly in our gardens can be quite discouraging. At RBG, we've had more damage each winter with a growing population of deer. These past weeks we've observed their tracks out in the gardens and we'll head out next week to assess some of the damage. Down below are some images of hostas and arborvitae that have been nibbled; two of their favorite treats. I was recently reading the newsletter for the Midwest Regional Hosta Society (www.midwesthostasociety.org) and it included some interesting information regarding some newly developed repellant that shows some promise. It is important to mention that this society has donated funds in the past to support our gardening efforts at RBG. A Duluth, MN scientist has essentially developed a way for plants to absorb hot pepper concentrate into their roots and up into the leaves, rendering them too hot for deer to munch. What I've included below is directly from the newsletter which was based on excerpts from the Duluth News Tribune. Tom Levar, a forestry and horticulture specialist for the University of Minnesota - Duluth's Natural Resources Research Institute, developed this idea using a chemical first used to treat muscle soreness in racing horses and, later, human athletes. The benign chemical, called DMSO, absorbs quickly through animal and human skin in to the bloodstream. Levar found out that it passes through the plant "skin" as well, and then combined DMSO with several bitter and otherwise unpleasant tasting chemicals. Pepper concentrate offered the best combination of being easy to use, natural and extremely effective. "You can use it when the plant is first put in the ground or incorporate it into the soil with established plants," said Levar, adding that the plant will even emit a peppery smell. People "don't notice the smell as much, but the deer sure know what it is...It's not really clear which is the better deterrent, the smell or the hot taste. usually it's one bite and they move on."
The pepper concentrate, called capsicum, is natural and doesn't harm the plant. The stuff also works great to keep dogs, cats, rabbits, mice, voles, moles and gophers from eating plants and young trees, Levar noted. In tests at an Alexandria, MN tree farm that had suffered huge losses of young conifer trees to field mice, the repellant proved 100 percent effective. Michigan-based Repellex, USA already had purchased the licensing rights from the University and has applied to the Environmental Protection Agency for approval, expected late this year. Company officials expect to have Repellex Systemic Animal Repellent in store shelves in March. Gardeners can simply dig a few pellets in to the soil around the base of the plant and, when it rains or the plants are watered, the natural process of plant nutrient transfer will suck the stuff in. It will be available in tablet form at first and eventually sold in granules that can be simply shaken onto the ground around the plant.

Levar said Repellex Systemic will last three months or more, and company officials say the tests are showing full effect for an entire growing season. "This really changes the whole (deer repellent) industry because it's inside the plant. Everything else out there was really a short term solution that washed off and had to be re-applied repeatedly," said Elizabeth Summa, president of Repellex USA. "It's going to cost a little bit more (than spray-on deterrents) for a single application. But because you don't have to reapply it, it's going to be much less expensive in the long run." Levor notes that Repellex Systemic shouldn't be used on edible plants "unless you want your strawberries to taste like hot peppers," he joked. "You'd definitely be able to taste it."