The buck stops here: How to prevent deer damage to golf courses
Deer, Pythium and cutworms all have something in common. These pests cause significant damage to golf courses. Deer, however, are likely to leave turf alone and concentrate their assault on ornamental plants such as those behind the backdrop on No. 3 green, the hostas near the practice putting green or the grand pansy display in front of the clubhouse.
Each year superintendents repair or replace thousands of dollars in damage caused by these large hungry grazers. Managing deer to reduce damage on the golf course demands an integrated approach, the same as any other pest. Knowing your enemy is critical to your defense plan.
When creating an integrated deer management program, keep in mind the following:
Deer are creatures of habit, and habits are harder to break than prevent. This explains why deer will readily go through fences installed over their familiar trails or why they return every spring to graze and destroy the same azalea blooms. This also explains why you must use management tactics consistently and with a heavy hand when you are “breaking” a population of deer used to grazing on your landscape.
Deer are adaptable, observant and more intelligent than we tend to give them credit for. This is why many scare tactics (see below) only work for a small window of time, before deer learn to ignore what they determine to be no real threat.
Deer have strong preferences about what they eat. Utilizing deer-resistant plants helps thwart major damage. For the same reason, if you plan to use plants favored by deer you must anticipate using methods to prevent deer damage. As with any pest management plan, combining tactics will result in the greatest success.
Deer Favorites | Deer-resistant Plants | ||
---|---|---|---|
Yes, you can successfully use plants that are deer favorites. In doing so, plan to provide vigilant maintenance that includes repellents. Choose a high-focus location, and monitor closely for deer activity. Using deer-resistant plants will further help the odds of success for ornamental beds on your course. Check with your local Extension office for a more expansive list of deer-resistant plants in your region. | Pansies | Daffodils | |
Azaleas | Sedums | ||
Hostas | Ornamental grasses | ||
Impatiens | Ageratum | ||
Tulips | Marigolds | ||
Roses | Ornamental alliums | ||
Lantana | |||
Cosmos |
Wildlife management experts cite five distinct methods for preventing damage caused by deer (see below table). Of these methods, the last two (highlighted) prove to be the most viable combination for the golf course.
Plant Selection. Unfortunately, many plants we favor as ornamentals are among the deer’s favorite snacks. However, some ornamentals are far less palatable to deer, and they will usually leave these alone. That said, no plant can be advertised as “deer proof,” as extremely hungry deer have been known to ravage even these. But selecting plants not favored by deer puts the odds of a successful planting in your favor.
Furthermore, plan to have ornamentals concentrated in fewer areas, which can be easier to protect and manage against deer damage. Choose a location that you frequently manage rather than an area tucked in a corner off the back nine where it is likely to be serviced less often. Members will appreciate a single bed filled with showy knockout roses rather than 10 beds with scattered stumpy, flowerless stalks on them.
Repellents. The most effective deer repellents employ an odor offensive to deer, and discourage the animals from the area (versus those applied to plants that have an unfavorable flavor for the deer). Liquid Fence and Pro Scram are two examples. Most products advertise that no offensive odor (created by active ingredients such as sulfur; putrescent egg solids; or garlic) is noticeable to humans after applications have dried or settled. Unfortunately, the applicator and anyone nearby will notice the odor during the window of application.
However, one brand, I Must Garden, has cornered the market on creating an effective deer repellent that is not revolting to humans. By using a potent mix of botanical oils, these products have proven as effective as their traditional stinky counterparts, but you can use them closer to your clubhouse or outdoor patios without offending guests. In true IPM fashion, however, using a rotation of these repellents seems an appropriately vigilant course of insurance against a hungry deer population.
Deer Management Techniques | Examples/notes | |
---|---|---|
Culling* via nuisance permits | *Optional only in some municipalities. | |
Fencing | Electric fences or double fences are most effective. Trunk wraps on saplings. | |
Scare tactics | Sound recordings, human hair, soap, predator urine. | |
Plant selection | Choose deer-resistant species whenever possible. No plant is fully “deer-proof.” See sidebar, page 25, for recommendations. | |
Repellents | Apply consistently and on schedule for best results. Opt for those that repel via odor, not taste. |
Repellents are available in liquid and granular formulas. Depending on the brand, both have similar durability under rain or irrigation. Liquid repellents are messy to mix and apply, but they offer protection higher off the ground, and you can apply them directly on prized plants.
Granular products, on the other hand, protect only low-growing plants (less than 6 inches high). If deer pressure is particularly strong, either because your plants are a premium investment such as tulips or roses, or because you know deer are likely to return based on past years, plan to use an aggressive program of repellents. Apply these often and always follow the product label. You may even combine granular and spray types.
In addition to coating the target plants with a repellent spray, apply repellents along the perimeter of the ornamental beds. I suggest applying two lines of repellent. Spray the first line at the perimeter of the bed and second line about 6 feet to 8 feet out, where deer will encounter it first (see illustration). After a single season of using an aggressive repellent program, the deer usually learn to avoid these areas. At this point you may dial down the application schedule to lesser frequency for maintenance.
While their massive size and charming looks make them unique among the golf course pest line-up, the damage deer cause is anything but charming. Fortunately, employing a savvy plant selection combined with a schedule of repellents has proven effective in protecting ornamentals against these pests on and around the course.
Where should deer repellent be applied?
Hover over a circle where you think deer repellent should be applied, and the answer will appear! There’s more than one correct circle.
Top photo: iStock.com (scorton) | Other photos by: Hannah Schrum | Illustration: Joelle Harms