By Christine Menapace
From the December 2023 Issue
If your landscaping business is located in an area with deer, this single factor affects plant selection as much as water, sun, and USDA zones. And these days, as human development decreases wooded areas, and natural predators are reduced, deer populations and their common ranges are increasing in some areas despite diseases like CWD and EHD. The University of Minnesota Extension points out that white-tailed deer is one of the few species that has a bigger population today than it did before European settlement.
(Credit: Adobe Stock / Ayusloth)
Identifying Deer Damage
Most deer damage occurs around this time of year — from late Fall through early Spring, when natural food sources are scarce. In fact, just one mature buck consumes between 4 to 10 pounds of food each day, including grass and other plants as well as buds and twigs, according to VT-based seed company, American Meadows. Complicating matters is that
no plant is off the deer menu given the right conditions. When I worked at a plant nursery, I was taught to tell customers we carry deer-resistant plants, but no plant is deer-proof!
So how do you know when plant damage is from deer and not other wildlife? Obviously height of the damage can be a determining factor, since deer can reach 6′ tall. Also take a close look at the damaged plant leaves. Interestingly, deer have no upper incisors, so when they eat, they must tear off plant leaves, leaving ragged edges. Rabbits and other rodents will leave clean cuts at a 45 ̊ angle.
On bark and small branches, rodents will leave teeth marks from the size of a fork tine to the tip of a spoon. Deer typically don’t leave tooth marks and eat branches less than one inch in diameter. More significant damage on trees, such as shredded bark, can occur from the antler rubbing of male deer.
Deterrent Strategies
What can you do about deer in landscapes? Since deer are creatures of habit, many experts agree that prevention is more effective than trying to change existing feeding behaviors. When damage does occur, then, it should be addressed immediately and not allowed to persist.
Since deer are creatures of habit, many experts agree that prevention is more effective than trying to change existing feeding behaviors.
It’s also important to be realistic. According to the University of Minnesota Extension, “You should not expect to eliminate deer damage completely. A 50% reduction in deer browse is very successful; a 30% reduction is a more likely result.” Why such low expectations? Because most deer deterrents are just that—deterrents, which by definition is a thing that “discourages,” not “prevents.”
Deer are persistent, and strategies to control them have their individual pros and cons. For this reason, a combination of strategies is recommended for the most success. Here are some suggestions:
Fencing. This is an obvious and effective strategy, but it may not always be realistic in terms of cost or geography. Also, fencing will need to be high, as much as 8′ to 10′ minimum, say some.
Repellents. Repellents are more effective if they are applied before deer become accustomed to foraging on garden plants. Commercially available products may or may not be effective due to factors including product formulation, rain, new plant growth, and deer appetite. North Carolina State Extension mentions old fashioned fragrant soap. “Drill a hole in each bar of soap and suspend it with a twist tie or soft twine on the outer branches of trees every 3′. Each bar protects an area of 1-square-yard. Replace as needed.”
NC State Extension also mentions a formulation of one to two tablespoons of Tabasco sauce in one gallon of water has been shown to have limited effectiveness, but they warn to test it on a single leaf first before spraying it on the entire plant. To note: ensure property owners never place mothballs as a deterrent since they are poisonous to pets and children.
Deer Resistant Plants. Plants with sticky or hairy leaves and stems, and foliage with a lemony or minty fragrance are less attractive to deer. Place these as garden borders to deter deer, says NC State Extension.
As mentioned, no plant is deer proof. For this reason, the Extension categorizes trees, shrub, and plants into three categories of: Frequently Damaged; Occasionally Damaged; and Seldom Damaged. For instance, frequently damaged landscape trees include redbud, Atlantic white cedar, and fringe tree; while black gum, pines, and live oak are seldom damaged. The full list of deer resistant plants for central and southeastern NC is available here.
Like NC State, Rutgers NJ Agricultural Experiment Station also rates landscape plants according to their deer resistance. Find the searchable database here.
American Meadows, mentioned earlier, works with customers across the U.S. Their top deer-resistant perennials include:
Achillea (Yarrow)
Aconitum (Monkshood)
Artemisia (Dusty Miller)
Ascleias (Milkweed and Butterfly Weed)
Asters
Astilbes
Clematis
Coreopsis (Tickseed)
Delphinium
Dianthus (Pinks and Carnations)
Dicentra (Bleeding Heart)
Digitallis (Foxglove)
Echinacea (Coneflower)
Ferns
Gaillardia (Indian Blanket, Blanket Flower)
Heuchera (Coral Bells)
Geranium (Crane’s Bill)
Ornamental Grasses (most varieties)
Iris (Japanese and Siberian Irises)
Kniphofia (Red Hot Poker)
Leucanthemum (Shasta Daisy)
Lavender
Liatris
Ligularia
Lily of the Valley
Lupine
Monarda (Bee Balm)
Nepeta (Catnip)
Papaver orientale (Oriental poppy)
Penstemon
Perovskia (Russian Sage)
Paeonia (Peonies)
Rudbeckia (Black-eyed Susan)
Scabiosa
Salvia (Sage)
Sedum (Stonecrop)
Tradescantia (Spiderwort)
Veronica (Speedwell)
Have Client Properties Gone To The Hogs!?
As a final note, perhaps one of the biggest factors in deterring deer with success starts with managing customer expectations. I recently inherited a vacation home in a heavily wooded area packed with deer. While it has a yard, I’ve had to seriously restrain myself from planting my favorite showy shrubs and perennials and realign my normal landscape aspirations. Instead, I plant very selectively and sparingly (and frankly experimentally), allowing myself to enjoy a different show of Nature: the does, fawns, and even the occasional buck that come to say hello.
Do you have a comment? Share your thoughts in the Comments section below, or send an e-mail to the Editor at cmenapace@groupc.com.