Taking an environmentally sensitive approach to pest management
Pest control in the garden usually conjures up images of fighting a seasonlong battle with insects, diseases and weeds. As troublesome as the latter three might be the damage they inflict often pales in
Taking an environmentally sensitive approach to pest management
Pest control in the garden usually conjures up images of fighting a seasonlong battle with insects, diseases and weeds. As troublesome as the latter three might be the damage they inflict often pales in comparison with that caused by some of four-legged “friends”. It is extremely frustrating to put time, effort and money into establishing an attractive garden only to have it decimated by the likes of deer, rabbits and squirrels. An abundance of wildlife coupled with a shift in human population to more rural and suburban settings makes the control of wildlife in the garden more of a challenge today.
Wildlife biologists suggest that motivation and habituation are two important factors that dictate the likelihood of garden damage by wildlife and probability of their successful control. The more highly motivated wildlife is to feed the more difficult it will be to prevent damage to cultivated plants. Hunger is a tremendous stimulus. During periods of dry weather when food in the wild is sparse wildlife will be highly motivated to feed on garden plants. Additionally, once wildlife become accustom to using the garden as a food source it becomes more difficult to prevent future deprivation. Early intervention is important if control is to be successful.
Controlling wildlife damage is best accomplished using Integrated Pest Management (IPM) strategies starting (when possible) with planting resistant species. Plants that have pubescent or hispid leaves, pungent aromas or a bitter taste usually are shunned by wildlife. For example, the following table is a partial listing of popular ornamental plants that deer tend to shun because of texture, odor or taste.
Devices or techniques that frighten wildlife can be effective deterrents when used properly. Propane exploders and pyrotechnic devices such as noise bombs, screamer shells and firecrackers are examples of auditory repellants. The result (of their use) is not permanent and their effectiveness depends on the frequency of use as well as the ability of wildlife to become acclimated to the noise. Variables such as timing and diversity of noise also must be considered. For example, once in place, nuisance animals such as birds are less likely to respond to noise once they have habituated an area. Additionally, a variety of noises is more effective than a single noise used repeatedly.
Visual devices that frighten animals such as scare crows, predatory bird figures, tin foil or pie plates and mirrors can be helpful. As with noise, the tendency for wildlife to become acclimatized to these deterrents lessens their effectiveness. Relocating them on a regular basis is recommended.
Chemical wildlife repellents usually are classified as gustatory (taste) or olfactory (odor) in their action. These repellents most often are sprayed (brushed) on vegetation and may contain a sticker of some sort to make them more rain-fast. Their effectiveness depends on a number of factors including motivation of the animal to be repelled, habituation of the animal(s) in question, concentration of the repellent, palatability of the plant being protected, rainfall and number of applications. Suffice to say the hungrier an animal is the less likely it will be deterred by a chemical repellent.
An easy “home-made” repellent consists of a mixture of 20 percent whole eggs and 80 percent water (by volume). It reportedly is quite effective against deer. This mixture tends to withstand weather but should be reapplied on a monthly basis. Commercial repellants are widely available and vary with regard to active ingredients. Several newer products contain capsasin, the chemical that imparts the “fire” to hot peppers.
When choosing chemical repellents, factors such as human (or pet) safety, toxicity to plants, and expense should be considered.
Fencing, netting, cages or other methods that exclude wildlife from garden plants can be very effective in controlling damage. However, depending on their nature and the building material used, they can be expensive. The use of 36 inch high chicken wire buried six inches in the soil is effective in controlling small animals such as rabbits or squirrels. A fence eight feet in height is considered to be an effective barrier for deer and wildlife other than birds. Woven wire (chain link) fences are most effective