Landscape contractors use many tactics to deter deer damage

Photos courtesy of American Deer Proofing unless otherwise noted.

More landscape contractors are finding that to keep clients happy with their landscape investments, they need to offer protection against what has become one of the biggest pests of all: deer.

“People spend $10,000 putting in a beautiful landscape only to come home and see the deer have eaten half of it. Especially in the winter, there’s not much for the deer to eat, so they’ll be doing anything they can to survive,” says Dell J. Sadler III, describing the problem in a mere two sentences. Sadler has been running Dell J Sadler III, Inc. for the past 15 years. It provides a range of property management services in and around St. Michael’s, Md., a charming small city on the Chesapeake Bay.

Sadler says in the beginning of his company’s business, he would install ornamentals for a client “and then the deer would come along and treat it like a buffet.”

He looked for a way to provide deer repellent services for his clients and conducted tests on azalea plants, treating them with different solutions and keeping records. He also put out a row of corn in the woods, spraying half the row with one creation and half with another.

“Some of the products smelled so bad I don’t think I could have paid my guys to spray it,” Sadler says. “It took a while to find something that was pleasant to smell as well as effective. We worked on that for more than a year.”

The result: a proprietary product with a peppermint-based formula that has a pleasant odor for humans but not for deer, says Sadler.

“The product does stick and last, but it does need to be reapplied through prolific growth periods,” Sadler says. “If we have a really excessive amount of rain, we have to get back out and reapply.” Since deer can be trained to stay away from a specific place, the fees for the deer service decrease after three months when less product application is needed, Sadler says.

Dell J. Sadler III, Inc.’s peppermint-based spray formula is a pleasant odor for humans but deer try to avoid it.
Photo courtesy of Dell J. Sadler III, Inc.

“However, what happens is new ones (deer) are born and they don’t know the areas to stay away from, so all of a sudden they run over and start eating it and the mother deer starts eating it again, so it is important to keep reinforcing that protection,” he says.

Sadler adds that in the prolific spring growing season, application visits are every three weeks, and that the deer repellent applications average 18 a year, with a monthly charge.

Plant damage is the biggest problem his clients cite with respect to deer, so the company maintains a list of deer-resistant plant materials.

“Most natives are deer-resistant because they naturally grow here and the deer have been co-existing with them for many years,” he says. “Deer won’t eat daffodils, for instance. They just won’t touch them. There are certain things you can grow that the deer won’t be inclined to damage. But when you get into situations like the winter, they tend to eat whatever they can find.”

Just as in other aspects of landscape maintenance, some contractors prefer organic approaches, others prefer traditional chemicals and some utilize a hybrid approach.

American Deer Proofing in West Kingston, R.I., began as a service for trees and shrubs sold at a nearby nursery in the late 1990s. The company develops, tests and deploys deer repellents for decorative plants and landscapes from which these animals enjoy feeding.

With deer being a problem, the nursery would guarantee the plants for a year, says David Martin, director of sales and customer service. Deer would eat the plants, so the nursery developed a formula to keep the deer away from ornamentals so they wouldn’t have to replace them within a year.

Mike Gaunya, who bought the company in 2003 after the original owner didn’t want to do the spray program for the nursery anymore, grew the company into more than 500 spray accounts both winter and summer, primarily for the residential sector in Rhode Island and southeastern Connecticut. The company has three field employees and a salesman in addition to Martin and Gaunya.

“We have more customers requesting services in the winter than we do in the summer,” says Martin. “A lot of people just think of deer repellent as a summer type of issue, but in reality, a lot of the expensive shrubs and trees that deer like to eat they eat in the winter.”

Eco-friendly approach

The company’s Everguard formula is designed to deter deer and rabbits and has undergone four revisions since it was originally developed, says Martin. The formula is exempt from registration by the U.S. EPA. While, because of its ingredients, it does require more applications than the company’s previous formula, it’s an effective tool in keeping deer from eating plants.

Technicians spray the plants (in the winter especially arborvitaes, holly and yews) and once the product dries, it gives off an odor.

“If deer try to bite it, there’s also a taste deterrent,” says Martin. “It does not mean that it’s going to keep the deer from passing through your property or feeding on your lawn, but it will help to keep the deer from eating your shrubs, which are very expensive to try to replace.”

Deer will not return if the area is not along their trail, Martin says. “All deer have established trails,” he adds. “About 1 square mile is considered a deer’s territory. They do have specific routes they take. They may pass through if the trail goes through your property, but if they stray outside or off the trail to a property and it’s been sprayed, chances are they won’t go back to that property.”

Fences and guns

Martin says “it usually takes a couple of years” to really get the deer to stay away. “I tell everybody there are only two ways to guarantee 100 percent that the deer won’t eat your plant and that is a good fence or a good shotgun.”

Repellents will work to a certain point, but if the deer are hungry enough (and this winter with all of the snowfall, that’s likely the case) they are going to eat even if it smells or tastes bad, he says.

“It’s the same with humans; if we are hungry enough we’ll eat a sour apple because we have no choice. It’s in our genes to try to survive and that’s true of deer as well,” he says.

American Deer Proofing sprays client properties every seven weeks in the winter, and every five weeks in the summer.

“We give our spray customers a free bottle of our 1-quart ready-to-use product and we will refill that whenever they use it up,” Martin says. “We encourage our customers to get out there at least once a week with plants like hostas. It’s a very popular plant for people and also a very popular plant for deer.”

Encouraging the problem

What a property owner plants or places on a landscape may encourage a deer problem, Martin points out, adding “some people focus on their flowers in the summer and they really don’t have much in the way of rhododendrons or hollies, which are winter foods for deer. Deer are very adaptive. Usually they know better than to strip a plant completely. They won’t necessarily take all of the leaf off or the green stem.

“The plant will come back in the spring and flourish in the summer and come fall, they are ready to be chewed up again,” says Martin. But sometimes hungry deer will eat whatever they can reach and they’ll damage expensive plants so severely they won’t recover.

Other landscape items may also attract deer to a landscape, including bird feeders. “I have four customers who have bird feeders everywhere,” he says. “Deer love bird feed.”

No plant “deer-proof”

While the type of plants utilized on a property can make a big difference, there is no such thing as a deer-proof plant, claims Martin.

“There are deer-resistant plants out there and for the most part, the deer will leave them alone,” he says. “We’re noticing this year in particular that even a lot of the so-called deer-resistant plants are actually being eaten by the deer.”

The reason: diminished acorn production. Deer love acorns.

“The acorn production this year wasn’t very good and we’ve had a couple of years in the last four years where acorn production has not been good,” says Martin. “Acorn is a staple for deer in the wintertime. To make matters worse, it was a very dry summer this year so a lot of their natural foods did not really come out for them to eat come the fall and winter.”

A “huge” problem

A traditional chemical approach has been the cornerstone of deer repellent services offered by Landscapes by Leonard in Poughkeepsie, N.Y. The company has been offering deer repellent services for 20 years to its residential clients in Dutchess County. The company, which was started by Leonard Futyma in 1964, offers the services as part of a full line of other landscape installation and maintenance services.

Until now, Poughkeepsie had not had deer problems. Now, quite a few of Futyma’s clients request deer repellent services.

The primarily complaint of clients is that deer are eating the plants and some high-end plants are being beaten up badly when bucks come in and rub their antlers through the trees, says Jeffrey Futyma, vice president. “For a new plant, a lot of times they run their antlers on there,” he adds. “If they know that’s not a place to browse and eat plants, they tend to stay out of those areas. We protect the trunks of new plantings with wire fence and then monitor it through the years to make sure it stays loose and doesn’t grow into the plant.”

Unless deer are starving they generally leave some greenery on the plants they eat. They don’t want to kill plants, their food source.

And that’s not the only issue. “We have a huge deer tick population. We’re close to Millbrook [a private, co-ed preparatory school] where there has been some extensive testing. The Cornell Cooperative Extension Services in Dutchess County and the Cary Institute of Ecosystem Studies in Millbrook have done a lot of testing of a lot of products and haven’t been successful with any one product. It seems like they have to switch up a lot,” says Futyma.

A bitter approach

Landscapes by Leonard utilizes Defiant, a fungicide and animal repellent based on the active ingredient Thiram.

“In the winter, I found that scent-based deer repellents don’t work,” says Futyma. “It has to be a taste-based deer repellent, something that is really awful in flavor. Thiram is bitter in flavor.”

The company must be registered with the New York Department of Environmental Conservation and Futyma has to report the amount of Defiant being used.

The company mixes Thiram with TransFilm from PBI Gordon, an anti-transpirant and sticker designed to reduce water loss of plants. “The reason we do that is it doesn’t leave as much of a residue on the plant,” says Futyma.

Futyma has used various products over the years in an effort to find the most effective in results and cost. Two decades ago when the company started offering deer repellent services, there weren’t many choices, and clients were saying the solutions they were using were ineffective. “Thiram was the only thing out there that seemed to work,” Futyma says.

Weather impedes application

The company usually initiates the service in mid- to late November and again in January, weather depending.

“It’s tough because we have to look for days that are warm enough to go out and spray,” says Futyma. “Sometimes it’s a very limited day. Sometimes there are weeks where we can’t do it at all. This year, we ended up going up right after Christmas. The first week in January was supposed to be so cold we weren’t going to be able to get out there.”

It generally takes a week to service all of the clients once the company is able to make it out.

Futyma is thinking about mixing hot sauces in with the Thiram because of the lower mix ratios, and he’s also considering using Deer Guard deer repellent, which is based on the active ingredient Bitrex, a bitter chemical.

His concern is that a 2.5-gallon pre-mixed container of Deer Guard costs $25 and he can easily go through a gallon and a half on a small property. “It sounds really good to me, but the issue is price,” says Futyma. “If I raise my prices a lot, will I still retain the customers to cover that product or do I continue with the product I have and keep it up with hot sauce?”

The bottom line for Futyma is that providing deer repellent services has given his company a decent revenue stream. Most clients utilize the company’s other services, but there are a few clients who use only the deer repellent services.

“Some of the clients’ properties are pretty large and it could be a $400 treatment, so it’s definitely worth going out and taking care of that client just for that one service,” Futyma says.

More resources

There are a number of resources available for landscape contractors seeking more information on repelling deer on client properties.

Rutgers University has a list of landscape plants at, which rates plants by deer resistance, from rarely damaged plants to frequently and severely damaged plants.

The University of California’s Agricultural and National Resource’s IPM Online program has a number of tips on the biology and behavior of deer and management through detection, fencing, individual plant protectors, repellents, frightening and other control methods. You can see that those at

Carol Brzozowski, Coral Springs, Fla., is a member of the Society of Environmental Journalists and a frequent contributor to Turf magazine. Contact her at