Imagine you need to eat seven pounds of salad greens every day to maintain body weight, and that your children need nearly that. Such is the daily feeding agenda of your familiar neighborhood deer.

According to Scott Williams, Ph.D., a wildlife biologist at the Connecticut Agricultural Experiment Station in New Haven, “Connecticut’s deer population is down from 10 years ago, when it reached unsustainable density.”

Williams includes roadkill, several winters with heavy snow loads during the past decade, and relaxed hunting regulations among the reduction factors.

While there are fewer deer overall, the feeding pressure on suburban landscape plants remains.

“No longer are we seeing deer in our large forest blocks. Rather, we are seeing them in and around human settlements where the habitat is more diverse and beneficial to wildlife in general. It’s likely due to several mild winters coupled with several fantastic mast years in a row,” he says, referring to the winters of 2015 and 2016. (The year 2017 is considered a non-mast year—see the sidebar about mast years.)

“In non-mast years,” says Williams, “you will likely see more damage to gardens and landscape plantings.”

Ouch.

Physical exclusion is the best way to avoid deer damage, but he adds that repellents are also effective.

Many people have turned to deer-resistant plants, too, but sometimes with disappointment. Also, many of these plants are not native, and some are very invasive such as tick-harboring Japanese barberry.

Monoculture Problems

Sean McNamara of Redding Nursery in northern Fairfield County points out one downside to the emphasis on deer-resistant plants.

“After 30 years of planting boxwood, andromeda, and dwarf Alberta spruce, we have created a monoculture,” says McNamara. “That monoculture invites problems. Boxwood leaf miner, psyllid, lace bug, and other pests that target these deer-resistant plants are on the rise.”

McNamara’s father, James, developed DeerPro Winter Animal Repellent more than 25 years ago. The spray repels deer (and other animals) by putting a repulsive taste on leaves that last through the winter after one application. All spray repellents rely on bad scents and tastes to ward off animals. Repulsive scents are more powerful in warmer months, while bad taste prevails in cold months.

McNamara Sr.’s invention caught on, and the company now treats thousands of properties around Connecticut. They also supply DeerPro to professional applicators (see www.ReddingNursery.com).

Plant a Full Palette

“We encourage our customers to plant the full palette of landscape material, including native flowering shrubs that, untreated, deer will eat,” says Sean McNamara. “The answer is to protect the plants during the limited time that deer feed on them with protective measures in the fall.”

Monroe-based Bobbex Inc. also markets a Connecticut-invented deterrent formula created by chemist Bob Ecstady more than 25 years ago. Their formulas are protein-based, combining meat meal, fish meal, and fish oil, among other ingredients. They work on both taste and scent. According to company spokesperson Brian McCall, herbivores such as deer and rabbits avoid scents and tastes that remind them of live protein sources.

This year, they introduced Bobbex Winter, which, according to Brian McCall, has more repellent along with a latex-based sticker-spreader. He recommends spraying the product when we have a few hours of above-freezing temperatures to help the spreader-sticker adhere to leaves.

McCall reminds us that animals become very determined to eat landscape plants in late winter when most other food sources are exhausted. Repeat spraying may be helpful at that point.

Though Bobbex products are a familiar presence in many garden centers, Bobbex Winter is only online at this time (see www.Bobbex.com).

If you are looking for certified organic deer repellents, visit www.OMRI.org and use the search window to find products.

Whether you decide to fence, cover, or spray valuable plants this winter, the Connecticut Agricultural Experiment Station offers lots of guidance and research on this topic—see www.ct.gov/caes. Use the search window to find “Limiting Deer Browse Damage to Landscape Plants” by Jeffrey Ward, “Effectiveness of Deer Repellents in Connecticut” by Jeffrey Ward and Scott Williams, as well as articles on Japanese barberry and ticks.

May all our landscape plants live to see the spring!

Kathy Connolly is a landscape designer, speaker, and writer from Old Saybrook. Reach her through her website, www.SpeakingofLandscapes.com.