Pests in Gardens and Landscapes: Quick Tips
Although pleasant to look at in the wild, deer can be very destructive in gardens, orchards, and landscaped areas, feeding upon a wide variety of plants. To confirm deer caused the damage, look for tracks, droppings, and trails. Excluding deer with fences or plant protectors provides the best long-term control.
Blacktailed deer doe.
Droppings are a good indicator of deer presence.
A 7- to 8-foot-high wire fence is the best way to exclude deer.
Deer biology and behavior:
- Deer eat shrubs, vines, fruit and nut trees, garden vegetables, grasses, and small flowering plants.
- Deer often feed late in the evening and very early in the morning, so you won’t always see them.
- They are especially a problem in gardens near woodlands that provide cover during the day.
- The two most common deer in California are the mule deer and the blacktailed deer.
Look for these signs to confirm deer damage:
- Hoofprints, 2 to 3 inches long, split in the middle, pointed at the front, and more rounded at the rear
- Piles of small jellybean-shaped droppings
- Trampled plants and shredded or ragged foliage, buds, or terminals
- Girdled trunks or branches broken by deer rubbing against them with their antlers
Be aware of legal restrictions.
- The California Fish and Game Code classifies deer as game animals. If deer are damaging your property or crops, you must get a permit to remove them by lethal means.
- Deer traps and poisons are illegal so can’t be used.
Protect your garden with fences.
- A properly built and maintained fence 7 to 8 feet high is the most effective control method. Fence height may need to be higher on steep slopes.
- Most existing fences can be made deer-proof by extending them 3 to 4 feet with mesh or smooth wire. Be sure the fence is sturdy and fitted to the ground, so deer can’t crawl under it.
- Use wire or plastic plant protectors to shield individual plants.
- Standard electric fences haven’t proven very effective. The New Zealand-type high voltage fence may be effective but should be professionally installed and constantly monitored.
Repellents and frightening devices:
- Chemical repellents that give off foul tastes or odors, such as the scent of a predator, can be useful in some situations.
- Repellents must be reapplied at frequent intervals, depending on what is used and the weather.
- Repellents may not work if preferred food sources for deer are available.
- Many repellents aren’t allowed on food crops or can damage some plants. Read the product label.
- Deer quickly adjust to most noisemaking devices such as propane cannons and electronic alarms, making them ineffective for the long term. However, some devices featuring deer distress sounds show promise.
Consider deer-resistant plants.
- There are plant species deer prefer not to eat, especially when more appetizing plants are available. However, when food is scarce, deer will eat most plants, including many deer-resistant species.
- Consult your local nursery and garden center, UC Cooperative Extension office, UC Master Gardeners, or refer to gardening publications about deer-resistant plants suitable for your area.
Minimize the use of pesticides that pollute our waterways. Use nonchemical alternatives or less toxic pesticide products whenever possible. Read product labels carefully and follow instructions on proper use, storage, and disposal.