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Chemical-free pest control

Hedgehog

Hedgehogs are great at limiting numbers of garden pests, such as slugs

Image: Niall Benvie

Many insects found in gardens have bad reputations as being pests and are subjected to an increasing number of chemical ways of ridding them from gardens.

Chemical control is often harmful to the environment and other wildlife that may not be the problem species the chemicals are aimed at. Many of the species persecuted are not actually harmful to gardens, or can be effectively controlled using other measures such as:

Natural predation – By encouraging natural predators of any specific pest into the area, the pest in question will be controlled. Ladybirds, lacewings, frogs, hedgehogs and birds are all great at limiting numbers of garden pests such as aphids and slugs.

Hand picking – although time consuming and intensive, removing areas of infestation by hand may be beneficial to the rest of the plot.

Water spraying – spraying with water or with a light soap solution has been used for some time to remove aphids and similar species from plants.

Organic deterrents – many plant oils and other organic based substances are totally environment friendly as they use plants natural resistance to attack but have a deterrent or lethal impact on specific garden pests.

Biological control – Whitefly can be targeted by a parasitic wasp, Encarsia. This works by attacking and paralysing the nymph of the whitefly reducing the number of whitefly and its impact on vulnerable plants.

Companion planting – By planting close together with species that attract predatory insects or disguise vulnerable plants, the impact on crop species can be reduced as pests are less likely to find their food plants.

Deterrents and Barriers – Many potential garden pests are sensitive to specific features. Slugs for example do not like copper piping or the sharp edges of eggshells so surrounding plants with such materials may keep many species away. Other methods to keep pests away are plastic bottles and straw around the base of plants.

The key point to remember with pest control in gardens is that you are not trying to remove the pest completely but to protect your plants and crops from serious damage. Most creatures that we see as pests are seen by our garden favourites as food, so encouraging more diversity within the garden will prove beneficial.

Ants; Friend or foe?

Ants do not do much damage in terms of flowers and crops. The main problem for gardeners is that ants will protect aphids from attack from ladybirds in order to harvest honeydew that the aphids produce in return for their protection.

Ants are more likely to be a nuisance, particularly when they leave piles of soil in lawns or move into buildings. Controlling ants using the various chemical measures available is only practical around buildings and not for the entire garden. If possible leave the ants to carry on with their routines around the garden, brushing the soil into the lawn on a dry day is all that needs doing.

Chemicals are generally a bad thing in a wildlife garden and can have impacts across the whole food chain so be cautious before using any chemical.