Ornamental and Garden Plants: Controlling Deer Damage

February 2017


Oklahoma’s white-tailed deer (Odocoileus virginianus) (Figure 1) population has increased from 40,000 to around 500,000 since the 1960s.  At the same time, urban development continues to move into deer habitat. Increasingly, homeowners at the rural/urban interface must deal with deer damage to ornamental and garden plants.  As deer begin moving into an area, homeowners initially enjoy seeing deer and may actually encourage them to come into their yard by feeding them.  Homeowner attitudes often begin to change after deer numbers increase to the extent that landscape plants show heavy browsing and gardens become difficult to grow because of continued depredation.
Deer have a varied diet that includes many broadleaf herbaceous and woody plants. Deer are not considered grazers (i.e. as are cattle) but rather are considered browsing animals.  They prefer to consume forbs (broadleaf herbaceous plants), shrubs, young trees, and vines. Deer will consume some species of grass, although damage is usually minimal.  While deer normally feed at night, as they become habituated to people, they frequently are active during the daylight hours. Deer have no upper incisors; they feed by tearing vegetation with their lower incisors and upper palate.  Thus, deer damage is easily identified by the jagged remains of browsed plant material.  Annuals are often pulled out of the ground completely. Woody plants are repeatedly browsed and often exhibit a hedged appearance (Figures 2 and 3). In addition to browsing, damage may occur in the fall when bucks begin rubbing antlers on small trees (Figure 4) or other young landscape plants.

Figure 1. White-tailed deer have become so abundant across Oklahoma that they are causing damage to property.

 

Figure 2. This elm shows classic browsing damage caused by white-tailed deer. Notice the hedged shape from years of browsing. Although this tree species readily resprouts each year following browse damage, deer are keeping the tree from reaching a tall stature.

 

Figure 3. An example of a browse line caused by deer. Woody plant species vary in how resilient they are to this heavy browsing. But regardless of potential plant mortality, browse damage can be aesthetically displeasing to homeowners.

 

Figure 4. Male white-tailed deer frequently rub trees both before and during the rutting period. They normally choose small saplings that have a thin bark layer. This is problematic for ornamentals in lawns and also for Christmas tree production.

 

Commonly Used Control Methods
The problem of damage control is not an easy one to solve.  Rural subdivisions normally ban hunting or place restrictions on firearm use to protect deer or for safety reasons.  Trapping and moving excess deer is often suggested by homeowners as a humane alternative to hunting.  However, the cost to move enough deer to lower damage to tolerable levels is prohibitive.  Also, most areas of Oklahoma are well populated with deer and any deer moved to another area will only shorten food supplies for both resident and transplanted animals.  The excess animals will then face starvation or decreased reproductive success because of chronic malnutrition.  Thus, trapping and relocating problem deer is a poor solution.

The first step in managing deer damage in the landscape is to make the landscape less attractive to deer.  This is accomplished by limiting the amount of excess food in the landscape through removing all unharvested fruits and vegetables.  Do not provide winter feed or salt for deer as an alternative to your landscape plants; the deer will feed on both the deer feed and your plants.  When deer damage becomes a problem in the landscape, control methods include:
1)    exclusion—by electric fence or eight-foot high, deer-proof fence,
2)    scare or frightening tactics—with dogs, gas exploders, fireworks or motion-activated sprinklers,
3)    population reduction through hunting,
4)    repellents—area repellents repel by smell and contact repellents repel by taste, and
5)    alternative plantings/habitat modification.

Physical Exclusion
The most effective deer damage control method is the use of exclusion fences. Deer can easily jump over many decorative fences. To keep deer out of a landscape or garden, either an electric fence or eight-foot deer fence (Figure 5) is necessary. A deer-proof fence does not fit well with most landscaping plans and can be expensive if large areas are to be protected.  One way to make fences less noticeable is to place them at the forest edge where they blend in with the surrounding shrubs and brush.  Many deer fences are constructed in such a way as to become nearly invisible from a distance and new fencing materials are even less obtrusive.  For small gardens, a deer-proof fence can be cost effective.  Many commercial deer fencing materials are available.  These are made of durable light weight polyethylene resistant to UV degradation.  Deer fences can also be easily constructed using standard hog wire fence and 12-foot posts.

Figure 5. Proper installation of a lightweight mesh deer fence using metal or wooden (4-inch by 4-inch) posts. Attach strips of brightly colored ribbon to the fence at 10-foot intervals, four feet from the ground to make the fence more visible to deer.

Electric fences (Figures 6a and 6b) are less expensive and can be just as effective; however, they do require greater maintenance.  For best results, electrify the fence immediately after installation and keep electrified at all times.  If an electric fence is not electrified for several days, deer may learn to go through it.  Researchers have had some success with a three-wire electric fence (“New Hampshire” spacing) when baited aluminum foil strips are attached at 5-foot to 10-foot intervals.  The ends of the strips are smeared with peanut butter for “bait.”  Deer may learn to jump electric fences if incorrectly installed or maintenance is lacking. For very small areas (e.g. 8-foot x 8-foot) shorter fences of around 4 feet may be sufficient to protect garden plots.  Deer can easily jump such short barriers, however they are normally hesitant to jump into small plots as it is more difficult to get out due to limited space within the plot.  However, for most gardens this will not be a viable option.
Young trees are particularly sensitive to deer damage and are often killed through browsing.  Individual trees can be easily protected from browsing damage using strong 8-foot tall wire cylinders (Figure 7).  Hog wire fencing is recommended as chicken wire is not strong enough for deer protection.  Stabilize the wire cylinder using t-posts and remove the fencing once trees have branched out of reach of deer.  This can also be used to protect trees from deer rubbing their antlers.

 

Figure 7. Wire cages can be used to protect individual trees from deer damage. Support cages securely using metal posts.

 

Scare Tactics
A number of scare tactics are used to frighten deer away from the landscape.  Dogs are very effective at repelling deer.  Products such as invisible fences allow the dog to patrol an area and see and harass deer that might be moving through.  These devices in combination with dogs can greatly reduce deer damage assuming the dog spends most time outdoors and will actually harass the deer.  Likewise, devices that produce loud noises or even flashing lights are often used to scare deer.  Propane gas exploders, strobe lights, and even radios can be effective when deer populations are low.   Another device is a motion activated sprinkler that is triggered when deer enter the garden.  When activated, the sudden noise, motion, and short burst of water emitted from the sprinkler frighten animals away.  Scare tactics work for only short periods of time, but may be useful by providing enough protection to allow the crop to be harvested.

Population Reduction
Population reduction by sport hunting is a cost effective, long-term solution to managing deer; however it is not often a realistic option as city ordinances prohibit hunting.  Where hunting is permitted, harvest with archery equipment is a safe option and deer meat can be supplied to various charitable organizations that provide food to the disadvantaged.  A number of meat processing companies provide the processing and packaging for free.

Repellents
Repellents typically reduce damage by 50 percent to 75 percent at best, and often much less.  If fences are not an option, repellents that have an unpleasant taste or odor may be a suitable alternative.  Area repellents utilize odors and are generally less effective than contact repellents that deter feeding through bad-tasting substances.  Table 1 summarizes research results on the relative effectiveness of area and contact repellents from several sources.  Many of these products are costly, and a cost-benefit analysis should be considered before application.
A number of household items are commonly used as area repellents including human hair, bar soap, cat or dog feces, and moth balls.  Most of these have shown little impact on deer browsing in scientific research; however, human hair and bar soap can reduce browsing up to 35 percent.  The repellents that have demonstrated the best efficacy are thiram-based contact repellents such as Chaperone and Spotrete-F and those made with putrescent egg solids.
Repellents can reduce damage, but will not entirely eliminate damage.  A deer will eat just about anything if food resources are limited.  Effectiveness will vary with deer density, season, palatability (or attractiveness) of the target plant, and availability of alternate foods.  To be effective, repellents must be applied before deer begin actively browsing in the affected area.  Keep in mind repellents will not completely eliminate damage and that a given method’s effectiveness will change seasonally, based on what natural foods are available to deer.  Many repellents do not weather well and will need to be reapplied after a rain.

Using Deer Feeding Behavior
Deer forage or feed selectively on different plants or plant parts.  Feeding habits change with the seasonal availability of plants.  Deer choose different plants and plant parts based on nutritional needs, palatability, and past experience.  Deer demonstrate preference for new plantings and fertilized and cultivated domestic varieties.  In Oklahoma, damage to ornamentals may occur at any time of the year.  However, most complaints occur in spring, in August during dry years, and after the first cold spell in fall.  Under circumstances of high population density or low food availability, deer may damage plants that they otherwise would not typically feed upon.  Deer also may exhibit some regionalized taste preferences.
Like humans, deer consume a wide variety of plants to meet their nutritional requirements.  Dietary and browse research in Oklahoma have documented more than 100 different species of plants comprising a deer’s diet in a given locale.  However, deer do tend to avoid certain plants and this knowledge can be used to determine which plants to use for landscaping and gardening.  The following list details many plants used in landscaping and in gardening by relative deer use.  From this list, you should be able to choose plants that will lower chances of damage occurring, or at least identify plants that may require some type of protection if they are to be grown successfully.
Judicious selection of plants in combination with various control methods should provide the rural or suburban homeowner with some realistic means of damage reduction.  Remember to begin control measures before significant damage occurs.  Garden plants that suffer rare or occasional damage when mature may suffer frequent damage at transplanting time (e.g., peppers, corn, okra, squash).  The same may be true with garden plants that are planted early in season and again in fall.  Thus, deer damage control strategies are more effective when implemented before the growing season.
In areas with severe problems, select only ornamental plants that are less frequently browsed by deer.  Even if a combination of plants prone to browsing and those less prone to browsing are used, damage may still occur because deer are selective feeders.  Realize that new plantings of less preferred plants may sustain damage in an area where extensive damage has previously occurred, and that younger plants frequently sustain damage because they are more palatable.
Finally, incorporating several tactics, such as planting resistant species, fencing vegetable gardens, and protecting already established, browsing-prone plants with a repellent will increase protection against deer damage.  Experiment with different tactics until you find what works best in your landscape.  For additional information on any of the above control measures contact your local county office of the Cooperative Extension Service.

Garden Plants—Severely Damaged
Common name    Botanical name

Beans    Phaseolus spp.
Broccoli    Brassica oleracea italica
Cabbage    Brassica oleracea capitata
Carrot     Daucus carota sativa
Cauliflower    Brassica oleracea botrytis
Kohlrabi    Brassica oleracea
Lettuce    Lactuca sativa
Peas    Pisum sativum
Spinach    Spinacia oleracea
Turnip      Brassica rapa

Garden Plants—Frequently Damaged
Common name    Botanical name

Beets     Beta vulgaris
Corn, sweet    Zea mays
Potatoes, sweet    Ipomoea batatas
Strawberries    Fragaria spp.

Garden Plants—Occasionally Damaged
Common name    Botanical name

Asparagus    Asparagus officinalis
Okra     Abelmoschus esculentus
Potatoes, Irish    Solanum tuberosum
Radish    Raphanus sativus
Squash    Cucurbita pepo

Garden Plants—Rarely Damaged
Common name    Botanical name

Canteloupe    Cucumis melo cantalupensis
Cucumber      Cucumis sativus
Eggplant    Solanum melongena
Hot peppers    Capsicum annuum
Onion    Allium spp.
Sweet peppers    Capsicum frutescens
Tomato    Lycopersicon esculentum
Watermelon    Citrulus lanatus

Herbaceous Plants—Annual Flowers
Frequently Damaged
Common name    Botanical name

Aster    Aster spp.
Impatiens    Imaptiens walleriana
Morning glory    Ipomea spp.
Ornamental sweet potato    Ipomea batatus
Pansy    Viola spp.

Herbaceous Plants—Annual Flowers
Rarely Damaged
Common name    Botanical name

Ageratum    Ageratum houstonianum
Amaranth    Amaranthus tricolor
Angel’s trumpet    Brugmansia spp. (Datura)
Blanket flower    Gaillardia spp.
Castor bean    Ricinus communis
Cosmos     Cosmos bipinnatus
Chinese forget-me-not     Cynoglossum amabile
Cupflower     Nierembergia hippomanica
Dusty Miller    Senecio cineraria
Flowering tobacco    Nicotiana spp.
French marigold     Tagetes patula
Globe amaranth     Gomphrena globosa
Heliotrope    Heliotropium arborescens
Lantana     Lantana spp.
Ornamental pepper     Capsicum annuum
Periwinkle    Catharanthus roseus
Polygonum     Polygonum capitatum
Poppy     Papaver spp.
Pot marigold    Calendula spp.
Salvia     Salvia viridis
Sanvitalia     Sanvitalia procumbens
Signet marigold    Tagetes tenuifolia
Snapdragon    Antirrhinum majus
Snow-on-the-mountain    Euphorbia marginata
Spider flower    Cleome hasslerana
Stock    Matthiola incana
Strawflower    Helichrysum bracteatum
Sweet alyssum    Lobularia maritima
Wax begonia    Begonia semperflorens
Zinnia    Zinnia angustifolia
Zinnia                    Zinnia elegans

Herbaceous Plants—Perennial Flowers
Frequently Damaged
Common name    Botanical name

Aster    Aster spp.
Day lily    Hemerocallis spp.
English Ivy    Hedera helix
Hosta    Hosta spp.
Sunflower    Helianthus spp.
Tulip    Tulipa spp.

Herbaceous Plants—Perennial Flowers
Rarely Damaged
Common name    Botanical name

Allium    Allium spp.
Amsonia    Amsonia spp.
Anise hyssop    Agastache spp.
Baby’s-breath    Gypsophila paniculata
Barrenwort    Epimedium spp.
Basket of gold    Aurinia saxatilis
Bear’s breeches    Acanthus mollis
Bee balm    Monarda spp.
Bergenia    Bergenia spp.
Blanket flower    Gaillardia spp.
Bleeding-heart    Dicentra eximia
Bleeding-heart    Dicentra spectabilis
Bugleweed    Ajuga reptans
Butterfly weed    Asclepias tuberosa
Cactus    many genera and species
Candytuft    Iberis sempervirens
Catmint    Nepeta spp.
Chrysanthemum    Dendranthema spp.
Columbine    Aquilegia spp.
Coneflower    Echinacea spp.
Coralbells    Heuchera sanguinea
Coreopsis    Coreopsis lanceolata
Coreopsis    Coreopsis verticilla
Corydalis    Corydalis spp.
Crocosmia     Crocosmia spp.
False indigo    Baptisia spp.
Flax    Linum perenne
Foxglove    Digitalis grandiflora
Foxglove    Digitalis purpurea
Gas Plant    Dictamnus albus
Gay-feather    Liatris spicata
Globe thistle    Echinops exaltatus
Golden marguerite    Anthemis tinctoria
Goldenrod    Solidago spp.
Grasses    many genera and species
Iris        Iris spp.
Italian Arum    Arum italicum ‘Pictum’
Japanese anemone    Anemone x hybrida
Japanese painted fern    Athyrium niponicum var. pictum
Joe pye weed    Eupatorium purpureum
Lamb’s ears    Stachys byzantia
Lavender    Lavandula angustifolia
Lavender cotton    Santolina chamaecyparissus
Lenten rose    Helleborus spp.
Lily-of-the-valley    Convallaria majalis
Lungwort    Pulmonaria spp.
Lupine    Lupinus polyphyllus
Meadow rue    Thalictrum spp.
Monkshood    Aconitum spp.
Narcissus    Narcissus spp.
Oriental poppy    Papaver orientale
Penstemon    Penstemon spp.
Plumbago    Ceratostigma plumbaginoides
Primrose    Oenothera spp.
Purple Coneflower    Echinacea purpurea
Ragwort    Ligularia spp.
Red-hot poker    Kniphofia spp.
Rose campion    Lychnis coronaria
Rosemary    Rosmarinus officinalis
Rue    Ruta spp.
Russian sage    Perovskia atriplicifolia
Sage    Salvia spp.
Sea holly     Eryngium spp.
Shasta daisy    Leucanthemum x superbum
Speedwell    Veronica spp.
Spurge    Euphorbia spp.
Sweet woodruff    Galium odoratum
Thyme    Thymus spp.
Toad lily    Tricyrtis hirta
Turtlehead     Chelone spp.
Virginia bluebells    Mertensia pulmonarioides
Wormwood    Artemisia species
Yarrow     Achillea spp.

Woody Plants—Frequently Damaged
Common name    Botanical name

Apples    Malus spp.
American Arborvitae    Thuja occidentalis
Cherries    Prunus spp.
Clematis    Clematis spp.
Cornelian Dogwood    Cornus mas
Eastern Redbud    Cercis canadensis
English Ivy    Hedera helix
Hybrid Tea Rose    Rosa x hybrida
Norway Maple    Acer platanoides
Peaches    Prunus persica
Plums    Prunus spp.
Rhododendrons    Rhododendron spp.
Catawba Rhododendron    Rhododendron catawbiense
Evergreen Azaleas    Rhododendron spp.
Winged Euonymus    Euonymus alatus
Wintercreeper    Euonymus fortunei
Yews    Taxus spp.
English Yew    Taxus baccata
Western Yew    Taxus brevifolia
Japanese Yew    Taxus cuspidata
English/Japanese
Hybrid Yew    Taxus x media

Woody Plants—Occasionally Damaged
Common name    Botanical name

Basswood
American Basswood    Tilia americana
Greenspire Linden    Tilia cordata ‘Greenspire’
Beautyberry    Callicarpa spp.
Border Forsythia    Forsythis x intermedia
Common Witchhazel    Hamamelis virginiana
Cotoneaster    Cotoneaster spp.
Cranberry
Cotoneaster    Cotoneaster apiculatus
Rockspray
Cotoneaster    Cotoneaster horizontalis
Dawn Redwood    Metasequoia  glyptostroboides
Eastern White Pine    Pinus strobus
Falsecypress    Chamaecyparis spp.
Firethorn    Pyracantha coccinea
Goldflame Honeysuckle    Lonicera x heckrottii
Hollies
Japanese Holly    Ilex crenata
China Boy Holly    Ilex x meserveae ‘China Boy’
China Girl Holly    Ilex x meserveae ‘China Girl’
Hydrangeas
Smooth Hydrangea    Hydrangea aborescens
Climbing Hydrangea    Hydrangea anomala petiolaris
Paniculated Hydrangea    Hydrangea paniculata
Japanese Cedar    Cryptomeria japonica
Japanese Flowering
Quince    Chaenomeles japonica
Lilacs
Japanese Tree Lilac    Syringa x reticulata
Late Lilac    Syringa villosa
Persian Lilac    Syringa x persica
Maples
Paperbark Maple    Acer griseum
Red Maple    Acer rubrum
Silver Maple    Acer saccharinum
Sugar Maple    Acer saccharum
Panicled Dogwood    Cornus racemosa
Pears    Pyrus spp.
Bradford Pear    Pyrus calleryana ‘Bradford’
Common Pear    Pyrus communis
Privet    Ligustrum spp.
Rhododendrons
Deciduous Azaleas    Rhododendron spp.
Carolina Rhododendron    Rhododendron carolinianum
Rosebay Rhododendron    Rhododendron maximum
Rose of Sharon    Hibiscus syriacus
Roses    Rosa spp.
Multiflora Rose    Rosa multiflora
Rugosa Rose    Rosa rugosa
Saucer Magnolia    Magnolia x soulangiana
Serviceberries
Downy Serviceberry    Amelanchier arborea
Allegheny Serviceberry    Amelanchier laevis
Smokebush    Cotinus coggygria
Oaks    Quercus spp.
Northern Red Oak    Quercus rubra
White Oak    Quercus alba
Spirea
Anthony Waterer Spirea    Spiraea x bumalda ‘Anthony Waterer’
Bridalwreath Spirea    Spiraea prunifolia
Staghorn Sumac    Rhus typhina
Sweet Cherry    Prunus avium
Sweet Mock Orange    Philadelphus coronarius
Trumpet Creeper    Campsis radicans
Viburnums
Judd Viburnum    Viburnum x juddi
Leather leaf Vibrunum    Viburnum rhytidophyllum
Doublefile Viburnum    Viburnum plicatum tomentosum
Koreanspice Viburnum    Viburnum carlesii
Virginia Creeper    Parthencocissus quinquifolia
Weigela    Weigela florida
White Fir    Abies concolor
Willows    Salix spp.

Woody Plants—Seldom Damaged
Common name    Botanical name

American Bittersweet    Celastrus scandens
Beautybush    Kolkwitzia amabilis
Buckthorn    Rhamnus spp,
Chinese Junipers
(green)    Juniperus chinensis  ‘Pfitzerana’
Chinese Junipers
(blue)    Juniperus chinensis ‘Hetzi’
Common Sassafras    Sassafras albidum
Common Lilac    Syringa vulgaris
Coralberry    Symphoricarpos spp.
Corkscrew Willow    Salix matsudana ‘Tortuosa’
Deutzia    Deutzia spp.
Dogwoods
Red Osier Dogwood    Cornus sericea
Flowering Dogwood    Cornus florida
Chinese Kousa Dogwood    Cornus kousa
Eastern Red Cedar    Juniperus virginiana  ‘Canaertii’
Elderberry    Sambucus spp.
English Hawthorn    Crataegus laevigata
European White Birch    Betula pendula
Forsythia    Forsythia spp.
Glossy Abelia    Abelia spp.
Hollies
Chinese Holly    Ilex cornuta
Inkberry    Ilex galbra
Honey Locust    Gleditsia triacanthos
Japanese Flowering
Cherry    Prunus serrulata
Japanese Wisteria            Wisteria floribunda
Kentucky Coffeetree    Gymnocladus dioicus
Norway Spruce    Picea abies
Pines
Austrian Pine    Pinus nigra
Mugo Pine    Pinus mugo
Red Pine    Pinus resinosa
Scots Pine    Pinus sylvestris
Virginia sweetspire    Itea virginica

Woody Plants—Rarely Damaged
Common name    Botanical name

American Holly    Ilex opaca
Barberry    Berberis spp.
Common Barberry    Berberis vulgaris
Blue-mist Shrub    Caryopteris x clandonensis
Boxelder    Acer negundo
Butterfly bush    Buddleia spp.
Buttonbush    Cephalanthus occidentalis
Catalpa    Catalpa spp.
Colorado Blue Spruce    Picea pungens glauca
Common Boxwood    Buxus sempervirens
Creeping Mahonia    Mahonia repens
Drooping leucothoe    Leucothoe fontanesiana
Dwarf Alberta spruce    Picea glauca ‘Conica’
Fiveleaf aralia    Eleutherococcus sieboldianus
Ginkgo    Ginkgo biloba
Heavenly bamboo    Nandina domestica
Japanese pieris    Pieris japonica
Japanese plum yew    Cephalotaxus harringtonia
Leatherleaf Mahonia    Mahonia bealei
Loblolly Pine    Pinus taeda
Mimosa     Albizia julibrissin
Oregon grapeholly    Mahonia aquifolium
Osage orange    Maclura pomifera
Paper Birch    Betula papyrifera
Pawpaw    Asimina triloba
Red yucca    Hesperaloe parviflora
River birch    Betula nigra
Shortleaf Pine    Pinus echinata
Southern waxmyrtle    Myrica cerifera
Spicebush    Lindera benzoin
Sumac    Rhus spp.
Yucca    Yucca spp.

Acknowledgements
Revised from an earlier edition written by Ron Masters, Paul Mitchell, and Steve Dobbs.  This fact sheet relied extensively on materials from Cornell Cooperative Extension, Wildlife Damage Management Program, Kentucky Cooperative Extension Service, Horticulture Magazine, February 1991, research from Penn State University, Connecticut Agricultural Experiment Station, Rutgers Cooperative Research and Extension, Michigan State University Extension, and personal observations and experiences of the authors in dealing with damage complaints in Oklahoma.  Mike Shaw, Research Supervisor (Retired), Oklahoma Department of Wildlife Conservation, provided numerous comments and suggestions.

 

David Hillock
Extension Consumer Horticulturist

Kimberly Toscano
Extension Consumer Horticulturist

Dwayne Elmore
Extension Wildlife Specialist

DASNR Extension Research CASNR
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Oklahoma State University
Stillwater, OK 74078
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