Integrated Pest Management

IPM Manual for Home and Garden Pests in British Columbia

Chapter 15: Pest Animals

Learning Objectives

When you have completed this chapter, you should be able to:

1. List the common animal pests of gardens and the damage they may cause.
2. List methods to prevent these animals from becoming pests.
3. List preferred and other control measures for these animals.

Introduction

The main approach to wildlife and domestic animal problems in home gardens and yards is to protect plantings with fencing or screen barriers of some type, or by using various scaring devices to change the behavior of the animals. Repellent chemicals are also available, but most are limited in use on or around food plants, and must be renewed frequently to maintain effectiveness.

Birds (Including Crows, Gulls, Robins, Sparrows, Starlings and Pigeons)

Damage

• A few species of birds eat seeds, seedlings, fruit, berries and nuts.
• Species that roost and nest on buildings create sanitation problems with their droppings.

Biology

• Most bird species are beneficial in the garden as they eat insects pests and weed seeds.
• Many bird species that cause problems (such as gulls, robins, and blackbirds) are protected by law and may not be harmed.

Prevention

• Cover fruit bushes, vines, and small fruit trees with bird netting or screen 2-3 weeks before first fruit ripens.
• Protect seeds and seedlings with floating row covers, chicken wire, or other protectors until plants are well established.
• Grow plants with berries preferred by birds (wild cherry, elderberry, and mulberry) to attract them away from domestic fruit.
• Use bird-scaring devices, such as scarecrows, reflectors, and fluttering objects. Birds become accustomed to such devices, therefore move them around the garden every few days.
• String wires 1-2 cm above the surface of roosting spots on fences and buildings.
• Place sticky compounds (polymerized butenes) along roosting areas according to label instructions.
• Apply bird repellents containing denatonium benzoate, to ornamental plants and trees, fence posts, siding, and garbage areas according to label instructions. Never use these products on food, edible plants, or directly on fruit or nuts of trees.

Other Measures

• For serious problems with pigeons, gulls and other birds roosting on or in buildings, consult a licensed pest control service to employ an integrated pest management program for problem birds.

Cats and Dogs

Damage

• Cats use dry soil under shrubs, cultivated garden soil, and children’s sand boxes as litter boxes. Cat feces are a health hazard as they are the source of toxiplasmosis infections in people.
• Dog urine damages plants. Feces are unattractive and unsanitary on lawns and garden areas.

Prevention

• Use a motion activated water sprayer, (for example, a scarecrow device), to train pets to stay away from particular areas. This method is particularly effective on cats.
• Cover freshly cultivated soil and bare soil areas under shrubs with bird netting, chicken wire, or commercially designed cat mats to keep cats from digging. Apply repellents containing denatonium benzoate (an ammonium derivative), methyl nonyl ketone, or pellets or twist-tie products containing essential oils of lemongrass, citronella, and other aromatic plants on, or around, ornamental plants, other garden areas, and on garbage cans to discourage pets. These are not for use on edible plants.
• Place wire fencing around trees and shrubs to prevent urine from reaching trunks and roots.

Other Measures

• Municipal bylaws all have "dogs at large" regulations — strays should be picked up.

Deer

Damage

• Deer browse succulent plant growth including flower heads, tender new leaves, and the shoots of many types of plants.

Biology

• Deer get in the habit of visiting "successful" gardens, therefore protecting plants involves changing the deer’s habits.
• Deer are often more of a problem in gardens when their usual wild forage plants dry up in summer.

Management in Areas with Occasional Deer

• Use a motion activated water sprayer to scare deer away from their favorite plants.
• If specific plants are being eaten, enclose them in chicken-wire cages, or cover with screen or floating row covers.
• Laying sections of loose chicken-wire or other fence wire flat on the ground around attractive plants or across pathways discourages deer because their feet get entangled in wire.
• Apply animal repellent products containing ammonia, denatonium benzoate or putrescent whole egg solids. Some repellents are not for use on edible plants and most must be reapplied after rain.
• Grow plants favoured by deer in areas of the yard where there is frequent activity by people, dogs, and other traffic that would startle the deer and keep them from developing a habit of visiting.
• Hanging mesh bags of human hair or bars of soap from trees sometimes works to reduce damage, though results are not consistent. These should be hung about a metre apart on the plants being damaged. The hair bags should be replaced monthly.

Management in Areas with Many Deer

• Invest in "deer-resistant" plants. Plants deer don’t usually eat are listed in garden books (for example, Sunset Western Garden Guide). Even in areas with high deer populations, there are some ornamentals that can be grown without significant damage from deer.
• Fence vegetables and ornamentals eaten by deer; woven wire fencing usually must be at least 2 m in height and extend to the ground. A horizontal extension at the top discourages them even further. Other types of fencing, such as electric fences and slanted fences, which are wide rather than high, are also used in some situations.
• Apply animal repellents such as ammonia, denatonium benzoate, or putrescent whole egg solids. Some repellents are not for use on edible plants and most must be reapplied after rain.

Other Measures

• Note: Repellents containing thiram are not recommended for home garden use due to the toxicity of the pesticide and its extreme side effects. Also, it is not for use on plants that are to be used for food or feeding purposes.

Rabbits

Damage

• Rabbits can extensively damage ornamental and vegetable gardens by digging and browsing on plants.
• During the winter, rabbits can kill trees and shrubs by eating the bark and girdling the trunks.

Management

• Fence the garden to keep out rabbits. Low wire fencing is sufficient.
• Cover vegetables with floating row covers. On small plants, such as lettuce and carrots, this can be left in place until harvest.
• Use a motion activated water sprayer (for example, a scarecrow device) to scare away rabbits.
• Wrap young tree trunks with commercial plastic spiral trunk guards or chicken wire to prevent rabbit damage in winter.
• Apply repellents such as ammonia or denatonium benzoate (an ammonium derivative) to plants. Check labels to determine if specific repellent is registered for use on edible plants.

Other Measures

• Note: Repellents containing thiram are not recommended for home garden use due to the toxicity of the pesticide (for example, because of side effects, alcoholic beverages should be avoided for 24 hours before or after working with thiram repellants). It is not for use on plants that are to be used for food or feeding purposes.