no. 6.520

Preventing Deer Damage

by C.E. Swift and M.K. Gross * (10/14)
Revised by Kurt Jones**

Quick Facts...

  • It is difficult to move deer out of areas where they are not wanted.
  • A hungry deer will find almost any plant palatable, so no plant is "deer proof."
  • The two types of deer repellents are contact repellents and area repellents.
  • Netting can reduce deer damage to small trees.
  • Adequate fencing to exclude deer is the only sure way to control deer damage.
Deer Damage

Although browsing deer are charming to watch, they can cause extensive damage by feeding on plants and rubbing antlers against trees. In urban areas, home landscapes may become the major source of food. Deer can pose a serious aesthetic and economic threat. Damage is most commonly noticed in spring on new, succulent growth. Because deer lack upper incisors, browsed twigs and stems show a rough, shredded surface. Damage caused by rabbits, on the other hand, has a neat, sharp 45-degree cut. Rodents leave narrow teeth marks when feeding on branches. Deer strip the bark and leave no teeth marks.

Management Strategies

It is difficult to move deer out of areas where they are not wanted. Not all strategies are practical for every homeowner. Frightening deer with gas exploders, strobe lights, pyrotechnics or tethered dogs typically provides only temporary relief. More practical management strategies include selecting plants unattractive to deer, treating plants with deer repellents, netting and tubing, and fencing.

Placement and Selection of Plants

The placement of plants in part determines the extent of damage. Plant more susceptible species near the home, in a fenced area, or inside a protective ring of less-preferred species. Table 1 lists plants and their susceptibility to deer damage. A hungry deer will find almost any plant palatable, so no plant is "deer proof." Also, a plant species may be damaged rarely in one area but damaged severely in another.

Repellents

The two types of deer repellents are contact repellents and area repellents. Contact repellents are applied directly to plants, causing them to taste bad. Area repellents are placed in a problem area and repel by their foul odor. Repellents are generally more effective on less preferred plants.

Apply repellents on a dry day with temperatures above freezing. Treat young trees completely. Older trees may be treated only on their new growth. Treat to a height 6 feet above the maximum expected snow depth. Deer browse from the top down. Hang or apply repellents at the bud or new growth level of the plants you wish to protect.

A spray of 20 percent whole eggs and 80 percent water is one of the most effective repellents. To prevent the sprayer from clogging, remove the chalaza or white membrane attached to the yolk before mixing the eggs. The egg mixture is weather resistant but must be reapplied in about 30 days. See Table 2 for a list of commercially available repellents and their ratings against deer and elk browsing in Colorado.

Home-remedy repellents are questionable at best. These include small, fine-mesh bags of human hair (about two handfuls) and bar soap hung from branches of trees. Replace both soap and hair bags monthly. Deer have been reported to eat the soap bars. Materials that work in one area or for one person may not work at all in an area more highly frequented by deer.

Netting and Tubing

Tubes of Vexar netting around individual seedlings are an effective method to reduce deer damage to small trees. The material degrades in sunlight and breaks down in three to five years. These tubes can protect just the growing terminals or can completely enclose small trees. Attach tubes to a support stake to keep them upright. Another option is flexible, sunlight-degradable netting that expands to slip over seedlings. Both products are available from Colorado State Forest Service offices.

Paper or Reemay budcaps form a protective cylinder around the terminal leader and bud. They may help reduce browse damage. Budcaps are rectangular pieces of material folded lengthwise and stapled around the terminal leader.

Tubes placed around the trunks of larger trees will help prevent trunk damage. Tubes may not, however, protect trunks from damage when bucks use the trees to scrape the velvet off their antlers. Fencing may be required.

Fencing

Adequate fencing to exclude deer is the only sure way to control deer damage. The conventional deer-proof fence is 8 feet high and made of woven wire. Electric fences also can be used. Electric fences should be of triple-galvanized, high-tensile, 13.5-gauge wire carrying a current of 35 milliamps and 3,000 to 4,500 volts. Several configurations of electric fences are used: vertical five-, seven-, or nine-wire; slanted seven-wire; single strand; and others. When using a single strand electric fence it helps the deer to 'notice' that the wire is there if it is marked with cloth strips, reflective tape or something similar. Otherwise, the deer may not see it in time and go right through it.

Additional options include invisible mesh barriers, slanting deer fences, and single-wire, electric fences baited with peanut butter. The invisible mesh barriers are polypropylene fences of various mesh sizes, typically 8 feet high with a high tensile strength, that blend in with the surroundings. The baited fences attract deer to the fence instead of what's inside the fence. They administer a safe correction that trains the deer to stay away. They are effective for small Gardens, nurseries and orchards (up to 3 to 4 acres) that are subject to moderate deer pressure. Deer are attracted by the peanut butter and encouraged to make nose-to-fence contact. Deer, like many wild animals, seem to respect and respond better to electric fencing after they become familiar with the fenced area. Additional information on fences and their construction can be found in Deer (Craven and Hygnstrom), available from Colorado State University Extension offices. (See references.)

Table 1. Plants and their relative susceptibility to deer browsing.
Often browsed Sometimes browsed Rarely browsed
Flowers
Geranium, wild
(Geranium fremontii)
Lupine, silver
(Lupinus argenteus)
Black-eyed susan
(Rudbeckia sp.)
Low sunflower
(Helianthus pumilus)
Pasque flower
(Pulsatilla patens)
California fuchsia
(Zauschneria sp.)
Nodding onion
(Allium cernuum)
Prairie coneflower
(Ratibida columnifera)
Daffodils
(Narcissus sp.)
Penstemon, low
(Penstemon virens)
Salvia
(Salvia reflexa)
Gaillardia/blanketflower
(Gaillardia aristata)
Phlox, common
(Phlox multiflora)
Scarlet gilia
(Ipomopsis aggregata)
Gayflower
(Liatris punctata)
Pussytoes, rose
(Antennaria rosea)
Tall coneflower
(Rudbeckia lacinata)
Grape hyacinth
(Cynoglossum officinale)
Strawberry
(Fragaria sp.)
Western wallflower
(Erysimum asperus)
Larkspur
(Delphinium nelsonii)
Tulips
(Tulipa sp.)
Wild iris
(Iris missouriensis)

Lavender
(Ravandula sp.)

    Mariposa lily
(Calochortus gunnisonii)
   

Mountain harebell
(Campanula rotundifolia)

    Pearly everlasting
(Anaphalis margaritacea)
   

Purple coneflower
(Echinacea purpurea)

   

Russian sage
(Perovskia atriplicifolia)

   

Thyme
(Thymus sp.)

   

Yarrow
(Achillea sp.)

Vines
Grapes
(Vitis spp.)
English ivy
(Hedera helix var.)
Virginia creeper
(Parthenocissus quinquefolia)
Trees and shrubs
Apples
(Malus sp.)
Alder
(Alnus tenuifolia)
Apache plume
(Fallugia paradoxa)
Aspen
(Populus tremuloides)
Golden currant
(Ribes aureum)
Blue mist spiraea
(Caryopteris x clandonensis)
Mugo pine
(Pinus mugo mughus)
Mountain maple
(Acer glabrum)
Common juniper
(Juniperus communis)
Rocky Mountain juniper
(Juniperus copulorus)
Ninebark
(Physocarpus monogynus)
Douglas-fir
(Pseudotsuga menziesii)
Roses (most)
(Rosea spp.)
Oregon grape
(Mahonia repens)
Hawthorn
(Crataegus sp.)
Wild red raspberry
(Rubus idaeus)
Wild plum
(Prunus americana)
Mountain mahogany
(Cercocarpus montanus)
    Oregon grape
(Mahonia repens)
    Pinon pine
(Pinus edulis)
    Potentilla/cinquefoil
(Potentilla spp.)
    Rabbit brush
(Chrysothamnus sp.)

 
Table 2. Relative effectiveness of repellents tested on hungry, captive mule deer and elk in Colorado during 1989, 1991 and 1992. (Compiled by W.F. Andelt et al.)
MaterialDeerElk
Hot Sauce® 6.2% hot sauceHighVery High
Hot Sauce® 0.62% hot sauceMediumMedium
Hot Sauce® .062% hot sauceLow - failureFailure
Deer Away - same as Big Game RepellentHighHigh
Chicken eggs (20% eggs, 80% water)High Medium
Coyote urine (100% urine)HighHigh
Habanero peppers (8% pepper, 92% water)MediumNot reported
Tabasco sauce (50% Tabasco, 50% water)MediumNot reported
Thiram (labeled concentration)MediumMedium
Hinder (labeled concentration)MediumMedium
Soap (Lifebuoy)Low-mediumNot reported
Ro-pel® (denatonium benzoate)FailureFailure
Ani-spray (denatonium benzoate, 3 x label) a FailureNot reported
a Products should not be used at rates above the labeled concentration.

References

  • Andelt, W.F. Managing Deer in Colorado. Outline for Master Gardener training in wildlife damage management. Department of Fishery & Wildlife Biology, Colorado State University.
  • Craven, S.R. & Hygnstrom, S.E. Deer. 1994. Prevention and Control of Wildlife Damage. Extension, University of Nebraska.
  • Jett, J.W. Resistance of Ornamentals to Deer Damage. Center for Agricultural & Natural Resources Development, Western Virginia University Extension Service.
  • Krahmer, R.W. 1993. Reducing Deer Damage to Conifer Seedlings. Hortus Northwest 4:1-3.
  • Mesner, H.E., Dietz, D.R. & Garrett, E.C. 1973. "A Modification of the Slanting Deer Fence." Journal of Range Management 26(3):233-235.
  • Wiles, J. 1998. "Deer Management Options." Landscape Management, January, p. 16.

*C.E. Swift, former Colorado State University Extension horticulture agent, Tri River Area, and M.K. Gross, former CSU Extension horticulture and natural resources agent, Eagle County. **Kurt Jones, Colorado State University Extension, agent, natural resources and agriculture, Chaffee County.12/01. Revised 10/14.

Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

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Updated Tuesday, October 07, 2014

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