In many places, deer are valued as watchable wildlife or game animals. However, where hunting is limited or no longer permitted and natural predators are few, deer populations can increase to a point where human/deer conflicts become a concern.
Problems associated with high deer populations include damage to crops, ornamental plants, restoration and reforestation projects, and deer/vehicle collisions.
Deer Fences
When deer browsing is moderate to severe, or a landowner isn’t willing to tolerate even a limited amount of damage, fencing to exclude deer is the only option. However, traditional deer fences are not always practical because of appearance, zoning restrictions, cost, or rugged terrain. In such cases, another type of barrier may be appropriate.
Before installing a deer fence, ask these questions:
- Do I need to protect my entire property, or only certain parts or plants?
- Is this need temporary, such as to protect young trees for a few years?
- Are there visual constraints, including aesthetics or sightlines?
- Are there any community or local government regulations or restrictions?
- Is building a fence time- and cost-effective, or should other methods be considered?
Before you build: If you decide to build a fence, construct it properly. A poorly constructed deer fence is dangerous to the deer, and will not protect your plants. Here are some general tips for building a deer fence:
- It is easier to build a fence while the land is vacant; when possible, fence an area before you plant an orchard or a garden.
- Enclose the entire area needing protection (including driveways). Deer will wander the perimeter of the fenced area until they find an opening.
- Keep fencing material flush to the ground (including under gates). Fill dips with gravel, rocks, logs, or other suitable material.Deer will try to crawl under or squeeze through a fence before jumping it.
- Deer can be excluded from areas with a properly constructed and maintained 6- to 8-foot-high fence.
- A board fence or hedge that prevents deer from seeing a safe landing zone on the other side needs to be only 5 1/2 feet high.
- Large areas with high deer pressure should be fenced with woven-wire deer fencing or a high-tensile electric wire.
Electric fences: A properly designed and maintained electric fence can be very effective at preventing deer from entering an area. Electric fences work by delivering a high-voltage but low amperage jolt that won’t set fire to plants or injure animals or humans. A fence with eight wires evenly spaced to 80 inches is believed to be adequate to keep deer out. Due to the variables in selecting a power source, and fence design and operation, it is best to consult a reputable dealer for more information.
Mini-barriers for individual plants
Barriers to protect small areas, individual plants, or vulnerable parts of plants can be purchased or made at home. These have the advantage of being less expensive and obtrusive than full fences, allowing deer access to surrounding food plants while protecting others.
To prevent deer from pushing over or moving a mini fence surrounding a tree or shrub, the fence should be 5 feet high and staked to the ground.
Netting—normally sold to protect berries and fruit from birds—can be draped over individual plants or used as a temporary fence, but deer can easily break lightweight netting to get to desirable plants. Stronger netting material is commercially available from bird-control outlets and companies selling polypropylene deer fencing. When draped over plants, any netting will need continual rearranging to protect new growth.
An inexpensive and subtle deer barrier can be made from 100-pound test monofilament fishing line tied to sturdy, 5-foot tall stakes, or attached to a structure. At a 12-inch spacing, fishing line works best to protect small enclosures, such as surrounding several rose bushes.
Commercially available tree guards protect trees from damage done to the bark from deer antlers and gnawing from other wildlife. They can be wrapped around nearly any size tree, cut to different heights, and expand as the tree grows.
Repellents
Deer repellents use a disagreeable odor or taste to dissuade deer from eating a treated plant. They are easy to apply and homemade solutions are inexpensive. There have been numerous studies to test the effectiveness of these repellents, often producing conflicting results. No repellent eliminates deer damage entirely.
Before you apply: Most repellents function by reducing the palatability of the treated plant to a level below other available plants. Hence, repellent effectiveness depends upon the availability of wild deer food. Repellents are more appropriate for short-term rather than long-term problems.
Repellents work best if applied before leaves or flower buds emerge and as new growth appears. It’s easier and more effective to prevent a feeding habit from forming than to try to break an established one.
To make your own repellent, mix the following in a 1-gallon tank sprayer:
- 2 beaten and strained eggs— strain them to remove the white strings surrounding the yolk, which otherwise will plug up your sprayer
- 1 cup milk, yogurt, buttermilk, or sour milk
- 2 tsp. Tabasco sauce or cayenne pepper
- 20 drops essential oil of clove, cinnamon, or eucalyptus
- 1 tsp. cooking oil or dormant oil
- 1 tsp. liquid dish soap
- Top off the tank with water and pump it up. Shake the sprayer occasionally and mist onto dry foliage. One application will last for 2 to 4 weeks in dry weather.