Extension Educator, Horticulture
Deer gracefully moving through the landscape–what a beautiful sight. In the early 1900's it was a rarer site. There were probably no more than 500,000 white-tailed deer throughout their entire range east of the Rockies. In some parts of their range they had been virtually eliminated. Now their population exceeds 15 million in the United States. Quite a comeback story.
Unfortunately deer can cause some real economic and aesthetic damage to landscape plants and crops.
First a note about tolerance. Wildlife is indeed wild. I would encourage tolerance of some wildlife damage. As people build homes in woodland areas and land uses change, the incidences of conflict between wildlife and people will naturally arise.
Deer love to nibble on leaves, stems and buds of many woody plants. In spring and summer non-woody plants are favorites. Fruits and nuts, especially acorns, are important in late summer and fall. Grasses are of little importance as deer food. Antler rubbing by males in the fall can be especially damaging to trees and young saplings along field edges. Bucks are marking their territory and rubbing velvet from their antlers, so the plant is chosen for its location not how yummy it is.
Damage caused by deer is not difficult to identify. Deer browsing often leave a jagged or torn surface on stems. Rabbit damage will leave a clean cut surface usually at a 45 degree angle like a good pair of pruners. Also the height of damage from the ground will rule out any wildlife other than deer or rabbits.
Deer prefer some plants. However, if deer populations are high and food is scarce due to snow cover, they will eat just about anything.
Woody plants least favored by deer:
Trees- ash, beech, birch, juniper, ginkgo, hemlock, honey locust, mugo pine and spruce.
Shrubs - barberry, boxwood, red twig dogwood, beautybush, American holly, forsythia, lilac and spirea.
Woody plants often severely damaged include: redbud, Norway maple, burning bush, yew, rhododendron, hybrid tea rose, arborvitae, apples and cherries.
Fencing is more effective than repellants in eliminating damage but requires special design features. Repellants should be used before extensive damage occurs. Repellants work as odor and/or taste repellants.
Consumer Reports magazine rated deer repellants in their October '98 issue. In their study, the weekly sprays were the most effective as opposed to sprays or sachets applied for season long control. The commercial product HinderS was listed as a best buy since it was fairly effective and inexpensive. Their homemade weekly spray (4 eggs, 2 ounces red pepper sauce, 2 ounces chopped garlic blended with water to make one quart and strained) was also effective.
If weekly spraying throughout the year is not feasible, consider a combination of methods - weekly sprays during the growing season if necessary, a few bags of soap for prized plants and a winter application of products such as Tree Guard®, Deer Away® or Deer Off®. Be sure to follow all label directions. Formulations of two tablespoons hot pepper sauce in twelve-and-one-half gallons of water with Wilt Pruf anti-dessicant has shown good efficacy as a winter application. Consumer reports study did state that using some repellant was better than nothing.
Bars of soap hung on trees have shown to be fairly effective repellents, but several bars may be needed. Their sphere of effectiveness is only about a foot. A 1992, a Cornell University study showed it is really the tallow fatty acid in soap and not the scent that repels the deer. Coconut fatty acid is far less effective so check the label. Human hair or blood meal in bags have had mixed results. Or consider a large dog with an invisible fencing system.