It’s hard to believe that just over a hundred years ago market hunting had almost eliminated white-tailed deer from America. But because of their adaptive nature and the disappearance of natural predators, there are now more deer than ever before. Guests staying at the Mohonk Mountain House in upstate New York, where I am the grounds superintendent, often ask how we keep the deer from eating all the plants. We have 500 acres of gardens and grounds that border the 7,500-acre Mohonk Preserve, and we have a lot of deer. Over the years, we have developed multiple strategies to prevent deer damage, and many of these methods can work in a home garden, too. To develop our strategies, which are based on the theory of integrated pest management (IPM), we became familiar with the deer’s annual cycle and used that timetable to determine when and where they will be eating. With this knowledge, we know the best time to use our most effective controls, which are fencing and repellents.

If fencing in your entire garden or property is a viable and economical option, it is by far the best strategy. Many fence styles and designs will effectively keep the deer out. The biggest considerations are aesthetics, the size of the area to be fenced, and the economic return. Since Mohonk Mountain House is a public garden and resort, perimeter fencing is not an option for us, so I erect temporary fences around specific plants and beds when I need them.

I use Cintoflex mesh fencing, which is made from a strong plastic that has UV inhibitors for greater longevity. To build a fence using this material I pound rebar or T-posts into the ground, then attach the fencing directly to the posts with plastic fasteners. If I can install it close to the plants, I use 4-foot-tall fencing. Deer do not feel comfortable jumping over a fence if they are going to land in trees or shrubs, so I place the fence as close to the plants as I can without having stems or leaves sticking through. If there is bare ground on the inside of the enclosure, I use 8-foot-tall fencing, instead, which usually does the trick, although an occasional deer might make the leap.

Another common method of control we use is spraying plants with repellents. I spray plants inside the fences as well as those outside because the fences can sometimes be toppled by heavy ice or excessive snow. The key to success with repellents is to start spraying them before deer begin browsing and to change repellents frequently, which keeps the deer from getting used to one taste. In the 15-acre core garden area around the buildings at the Mohonk Mountain House, I use only natural-based repellents such as Deerbusters, Deer-Off, Deer-Away, Liquid Fence, Milorganite, Plantskydd, Scoot Deer, or Bobbex. These products are made from ingredients like dried blood, food products, or biosolids. I have also had good luck with fish emulsion sprayed on the leaves, although its odor can be distasteful to humans as well. I have not had good results with predator urines. In areas away from the main buildings, I use some chemical-based materials, including Tree Guard, Thiram, Defiant, and Repellex. Results are variable, so some experimentation may be necessary to see what works best for you.

An annual timetable dictates deterrents

SEASONAL ACTIVITY

The rutting and breeding cycles begin.

Feeding habits
The deer continue eating mast crops, but raids into gardens become more frequent. They eat mostly herbaceous material and turfgrass until a hard frost forces them to switch to woody plants.

Control
Step up the frequency of spraying repellents. By the time a hard frost hits, be installing temporary fencing around important plants.