Advice
RHS Help & Advice
The safe use of pesticides
Some pests, diseases and weeds can be controlled by using pesticides. Their effectiveness may depend on the environmental conditions, so gardeners may need to try more than one pesticide (active ingredient) to find those that give the best control of the problem. If a non-systemic (contact) product has been found to give good control and has not proved too expensive, there is no point in changing to one of a different type. Regular use of certain systemic chemicals, however, may lead to the build-up of tolerance in the target organism, so that they cease to be effective. This is particularly the case with fungi and some insects.
All garden chemicals on sale in the United Kingdom are safe when used according to the manufacturers' instructions. To minimise any possible harmful effects arising from their misuse the following general rules should be observed.
When choosing a product
- Use chemicals only when they are really necessary. Prevention is almost invariably better than cure and many pests, diseases and weeds can be kept down by good cultivation techniques, such as rotation of crops, destruction of crop residues, hand removal, or thorough digging and drainage of heavy soils.
- You must select a chemical which is recommended for the particular purpose you have in mind. Always read the label before choosing a product.
- Only use a product that contains an insecticide as well as a fungicide if pests are a problem at the same time as a disease. Instead, choose an alternative, single-ingredient product.
- It is illegal to mix two chemicals together to give a combined spray, unless this is recommended on the product label or leaflet.
- Do not buy large quantities of pesticides that may take many years to use up. If only a few plants need treatment, one of the ready-diluted, ready-to-use pesticides is likely to be the most convenient solution.
When applying a product
- Always read the manufacturer's label and check for any limitations or specific precautions you should take. As an added precaution, wear rubber gloves, particularly when handling the concentrate and when spraying.
- Follow all the instructions on the manufacturer's label and apply the chemical at the stated rate and in the manner described. It is a legal requirement to comply with the Statutory Conditions indicated on the label.
- If spraying edible plants, check that the pesticide is labelled for use on that plant and note the instructions for the period of time that must be left between treatment and harvesting the plant (the harvest interval).
- Make sure that you are spraying at the correct times and intervals, as this is often crucial for the control of a pest or disease.
- Spray efficiently to wet the plants without excessive run-off or drift, but thoroughly wet the stems, buds and the underside as well as the upper surface of the leaves.
- Do not spray plants which may be injured by the chemical or allow spray to drift on to them. Because of the large numbers of species and cultivars of ornamental plants grown in gardens, sensitivity to products should always be checked on a small area or number of plants in the first instance.
Safety precautions
- Avoid pesticide contact with exposed parts of the body, particularly the eyes and mouth. Wash off any splashes immediately with clean water.
- Avoid breathing in dusts or sprays. Wash after using sprays or dusts.
- Make sure no children or animals are in the vicinity when spraying.
- Many pesticides, particularly insecticides, pose a risk to fish, amphibians and other pond life. Unless specifically intended for use in ponds, keep all products away from water courses, including ditches and streams.
- Do not smoke, eat or drink while spraying.
- Do not spray or dust in windy, completely calm or hot sunny weather. Spray in the early morning or late afternoon and evening.
- Clean all equipment after spraying. DO NOT apply fungicides and insecticides with apparatus that has been used for weedkillers.
- Always try to make up only sufficient solution for the task. Left-over spray must not be poured down the drain.
- Store chemicals in a cool, dry, frost-free, safe place away from children and pets, keep chemicals tightly closed and in their original containers.
Further information
Pesticide labels explained Clarification of the information found on pesticide labels.
Further information on the changes in pesticide legislation and the effects on availability of products
Safe disposal of old/unwanted pesticides