Deer, and Their Damage, Can be Controlled

As beautiful as they are, deer can be very destructive to gardens, orchards and landscaped areas, particularly in foothills and coastal districts where nearby woodlands provide deer with cover. Deer may damage a variety of plants, including vegetables, fruit and nut trees, grape and berry vines, grasses and many ornamentals. They cause damage by eating as well as trampling crops. Young trees or shrubs may also be damaged when deer rub their antlers on trunks and limbs.

Mule and black-tailed deer are the two species common in California. These deer eat a variety of vegetation, including woody plants, as well as some grasses and forbs (small broad-leafed flowering plants). They also consume fruits, nuts, ornamental trees, shrubs, vines and garden vegetables.

Because most deer feed in the late evening and very early morning, it is not easy to observe them. A good way to determine their presence in the garden or orchard is to look for hoof prints. Deer hooves are split, pointed at the front and more rounded at the rear, and are about 2 to 4 inches long. Smaller deer scat is like rabbit pellets, but large males have solid scat like a big dog.

Legal Restraints

Deer are classified as game animals by the California Fish and Game Code. If you find them damaging property or crops, you may obtain a permit from your local game warden to control deer by shooting them, although this method is not generally recommended for the problems homeowners encounter. Other methods of destroying deer, such as the use of traps, poisons or toxic baits, are illegal.

Deterrents such as fences, barriers and repellents can all be used without a permit.

Control Methods

• Fences

Properly built and maintained fencing is the most effective method for excluding deer. Deer normally will not jump a 6-foot fence for food, but if threatened, can jump an 8-foot fence on level ground. While 6-foot upright fences are usually adequate on level ground, a 7- or 8-footer is recommended, especially in the Sierra Nevada areas of California where larger deer are found.

On sloping ground, you may need to build fences 10 or 11 feet high to guard against deer jumping from above.

Determine the kind of fence you are going to build by assessing your needs, the expense, terrain and whether ore not they are allowed in your subdivision. Woven mesh wire attached the full height of the fence is preferable. If you need to economize, two or more strands of 9- or 10-gauge smooth wire can be stretched at 4 to 6 inch spacing above a 5 foot mesh. Vertical stays should not be more than 6 to 8 inches apart. There is no advantage to using barbed wire.

Because deer will crawl under a fence if they can, you should secure mesh wire close to ground level. An extra strand of barbed wire stretched along the ground will help keep deer from crawling under. Stake the wire firmly to the ground in any depressions between posts or fill the depressions with materials that will not deteriorate or wash away.

• Gates

With upright fences, gate height should be approximately equal to fence height. Keep weight to a minimum. A light wooden frame over which mesh wire is stretched is often satisfactory. If you use factory-made aluminum gates, you may bolt or weld on metal extensions and stretch mesh wire over them. It is advisable to sink a metal or treated wooden base frame in the ground below the gate to make a uniform sill and to keep deer from working their way under the gate.

Other control methods

In many places, protecting individual plants may be more practical and economical than attempting to exclude deer from an entire area. For example, young fruit or nut trees in a home orchard can be individually fenced until primary branches grow above the reach of deer. Two or more wooden stakes can be driven into the ground, and chicken wire or heavier woven wire can be attached to form a circle around the tree. Plastic trunk protectors may be useful for young vines and trees. Inspect individual barriers regularly.

Various chemical repellents are available as a means of reducing or preventing deer damage to trees, vines and ornamentals. Deer repellents are distasteful materials that make the protected plants less desirable as food sources for deer. It is important to remember that repellent materials must be non injurious to the trees or shrubs. Also, do not apply repellents to edible crops unless such use is specifically indicated on the product label. Repellents are useful under some conditions. Most are not registered for use on food crops except during the plants’ dormant season. They should be tested to make sure they are not phytotoxic (harmful to the plant).

When deer are hungry and a garden area contains highly preferred foods, repellents probably will not be effective. Repellents are ineffective with dense, severely competitive deer populations as well.

Deer, like all animals, have certain food aversions. Home gardeners living near a deer habitat can often take advantage of this by using deer-resistant plants for ornamental planting. Various factors can make a plant resistant to deer. Many of the most resistant plants (such as oleander) are poisonous, some at all times and others only at certain stages of growth. Palatability of non-toxic plants also varies with plant age and time of year.

A plant’s resistance to deer is also related to the availability of other food. If there is an adequate supply of native plant food, ornamental plantings may be largely untouched.

If the naturally occurring plant food supply is low, there will be increased browsing in domestic gardens. If there is an extreme shortage of natural food, few plant species will be totally resistant to deer. A heavy deer population also increases competition for food, with the result that plants normally unpalatable to deer may be browsed.

*Try this homemade recipe to repel deer:

• 1 egg
• ½ cup milk
• 1 tablespoon cooking oil
• 1 tablespoon dish detergent
• 1 gallon water

Beat the egg and milk together, then add cooking oil and detergent. Add mixture to water and stir or shake well. Store in a covered 1-gallon container.

Apply liquid to plants (except for food plants) using a spray bottle. Reapply every 2 weeks or after heavy rains.