Pest Control in the Garden
Created | Updated Mar 15, 2009
For the purposes of this introduction to pest control in the home garden it should be assumed that the maximum level allowed by law of control over the reader's children and pets has been achieved; and that the reader is already reconciled to the fact that nothing constructive can be done (under the law) about the neighbours' children and pets.
That having been said, the object of pest control in the garden is not to completely eradicate all insects and other nuisance beings, but to establish and maintain a state of equilibrium between the various guests of the garden that is favourable to the things you love at least as much as the things you hate. This is not only a more ethical approach to pest control than all out war; it is a strategy far more likely to lead to success.
Beneficial Insects and Others
Not all of the insects in your garden are undesirable. There are many, such as predatory beetles, mantids, and parasitic wasps, which are valuable allies to gardeners. Care should be taken not to harm or discourage these helpful creatures when we do battle with our garden pests.
Having a few unwanted guests in the garden is a good thing if it ensures that you also have a healthy resident population of beneficial insects. It is much better - and infinitely more achievable - to maintain a healthy balance in the garden than it is to create a situation in which populations of insects swing from one extreme to the other.
It is possible to introduce beneficial insects into your garden by ordering a pioneer population by post. There are many companies which specialize in this 'green' approach to pest control.
Toads should also be made welcome in our gardens, as they eat large quantities of slugs, the bane of the hosta patch. Providing a modest shelter, such as an old plant pot, and a place to have a drink is a good way to make toads feel welcome.
Snakes, hedgehogs, and many other small creatures all have a role to play in helping the garden grow, if given a chance, as well as providing an added interest in their own right.
The first, best, and most obvious way of controlling pests is to incorporate pest control into normal, everyday garden maintenance. This means tailoring what you do in the garden to making it as inhospitable to pests as possible, while giving the plants in your garden every opportunity to flourish.
Tidiness - Many insect pests spend at least a part of their life cycles in leaf litter and garden debris. By keeping your garden tidy and not allowing leaves and such to accumulate around your plants, it is possible to deny many insects the opportunity to reproduce.
Pruning - Pruning shrubs to remove dead or diseased branches and improve air flow will greatly improve the overall health of the plants and assist them in combatting pests, many of which are chemically attracted to plants in distress. The routine removal of older branches also serves to reduce egg masses and places of natural cover. This is particularly effective during Winter pruning, when pupae and egg masses are relatively easy to spot.
Plant selection - Simply put, this means not planting the things that are likely to attract an onslaught of pests. If there is a high incidence of a particular pest in your region, because of the climate or other factors, it makes sense to plant something else, unless you are willing to commit to a long-term battle.
Companion planting - It is often possible to offset the attractiveness of certain plants in your garden to insects by interplanting them with other things that the insects don't like. Many vegetable gardeners, for example, plant marigolds or nasturtiums amongst their crops in order to discourage pests.
The use of chemical pesticides is a contentious issue. It is also one that is strictly governed by laws, which may vary from place to place. Chemical pesticides are important tools which can be a very effective means of controlling insects. But it should be remebered that they are all toxic to humans to some degree, and many have residual effects on the environment that are only beginning to be understood. In general terms, it is always best to avoid the use of pesticides whenever an alternative solution is available.
Always follow the directions on the label to the letter. Never improvise or experiment with combinations of products or solution strength.
Always wear the recommended protective equipment, especially when mixing chemicals; and always wear a dust mask or respirator when handling dry chemicals.
Use chemicals for the purposes they are intended and nothing else. Check the manufacturers' recomendations for plants which are likey to suffer adverse reactions - many will!
Be extremely cautious about when and how chemicals are applied. Wind and rain can carry chemicals with unhappy consequences, but so can calm, sunny weather. Chemicals can drift as a vapour in warm weather, and cause damage to nearby plants. Never apply pesticides when children and pets are about; and follow the manufacturer's recommendations regarding a safe re-entry interval.
Always store pesticides in a dry place with good ventilation, preferably to the outside - a shed, for example. Keep them under lock and key, out of the reach of children and pets. Post a note on the outside of storage areas, warning firemen of the presence of pesticides.
Many insects are capable of developing immunities to pesticides, particularly the relatively benign products available to home gardeners. To make this more of a challenge for them, it is a good strategy to rotate two or three products with dissimilar chemical compositions.
Integrated Pest Management
Integrated Pest Management (IPM) is a horticultural maintenance strategy intended to control insect pests and diseases. IPM stresses cultural practices, plant selection, and natural predation, and minimizing dependence on chemical pesticides.
A common example is the use of introduced populations of predatory insects, such as mantids, to control garden insect pests. Cultural practices include pruning to remove egg masses and diseased tissue, and the removal of litter, both of which interrupt pest reproductive cycles.
Key to successful IPM is understanding the relationship of environmental indicators (such as bud break, blooming, or germination of specific plants) in the local environment to the life cycles of specific pests.