Not everyone likes to use chemical sprays in the garden and for those who don't there is a vast range of organic sprays to help control pests and diseases.
Organic methods for insect control include sprays for killing or repelling, the use of friendly predators and parasites, physical traps and deterrents.
Some can be purchased while the recipes for others have been handed down by generations of keen gardeners and are still practised today.
The infusion of two cloves of crushed garlic added to two litres of water can be sprayed over young carrots to protect them from the dreaded carrot fly.
Another effective method used to control these pests is to plant carrots between rows of garlic.
These repellents depend on masking the odour from the female carrot fly which lays its eggs in the ground near the carrots. The larvae eat into the roots on hatching.
Any female carrot flies that hatch from pupae already in the ground from the previous crop or have managed to overwinter on carrot-like weeds will not be deceived and the carrot crop may still be ruined.
Infusions were made from rhubarb leaves, tomato stems and leaves and stinging nettles by boiling in water to extract the active ingredients.
Such sprays are said to destroy some insects, especially aphids, without killing or harming the beneficial aphid predators such as ladybird larvae and lacewings.
Crushed laurel leaves which are used by butterfly collectors to euthanise specimens have the active ingredients extracted by soaking the crushed leaves in a spraying oil.
This mixture can be sprayed onto ornamentals, not food plants, to quickly eradicate insect pests.
The use of pest predators in the garden is as old as gardening itself but is fast becoming more common as their life cycles are better understood.
Predators include spiders, praying mantis, hoverflies, ladybirds, lacewings and extends to the parasitic species such as Encarsia formosa, a tiny wasp which lays its eggs in the pupae and lavae of whitefly, destroying them before they become adults.
The orb-weaving spiders which spin the familiar circular webs formed by spokes radiating out from a central ring may be caught and placed on a wire frame above the cabbage family.
Supply them with some spindly twigs to build more webs on and the cabbage moth will avoid them and retire to a safer place to lay their eggs.
A bacteria commonly used in organic gardens is Bacillus thuringiensis (dipel). This can be purchased from nurseries as a suspension and is sprayed onto plants that have been attacked by caterpillars.
The caterpillars die after eating the crystal of protein produced by the bacterium.
Each dead caterpillar then becomes a source of infection for other caterpillars, giving a long period of protection against these pests. This bacteria is harmless to beneficial insects, warm-blooded animals, birds, fish and humans.
Aphids can be controlled by adding a couple of teaspoons of dishwashing liquid to five litres of water then spraying directly onto the pests.
This spray is very safe but always apply two sprays, the second a week after the first to get those insects in the egg stage at the first application.
July 16: Australian Native Plant Society, Max Fry Hall, Gorge Road, Trevallyn, 7.30pm.
July 17: Launceston Horticultural Society, Windmill Hill Hall, High Street, 8pm. Speaker for the evening is Andrea O'Halloran from the Hillwood Strawberry Farm who will give an overview of berry fruit growing in Tasmania.
July18 : The Launceston Orchid Society, Newnham Uniting Church Hall, 7pm. Visitors welcome.