When combating pests in your garden, there is a four-tiered approach that you should take. Before diving into your garden centre t...
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With spring comes beautiful weather, a bounty of new green plant growth, colourful flowers, and heavenly fragrances. This is also when the insect, weed and disease pests descend upon our gardens and cause problems.
The best way to control pests is to use a four-step approach. The steps are: Cultural, physical, biological and chemical. Think of these in a pyramid shape, with cultural control being the broad base, then physical, then biological and at the top (smallest), chemical. When controlling pests, start with the base of the pyramid (cultural control).
The cultural pest control method includes:
Physical pest control is the keeping out, or physical removal of pests. Keep pests out by not bringing home plants that are infested with insects, weeds or diseases. Barriers such as screens, are meant to keep pests out. Physical removal includes traps, washing off, squishing, dropping in a bucket of soapy water, mulching, tilling, hoeing, mowing, pulling out, pruning off, etc.
Biological pest control is the use of living organisms to control pests. There are bacteria, fungi, nematodes, viruses, parasitoids and predators that all prey on pests. These good bugs are known as beneficials because they help to control pest insects in our gardens. Without us lifting a finger or spending a penny, beneficials search out and kill those pest insects for us – no charge. The less chemicals we spray, the more beneficials we will have.
There are many insect predators and parasitoids that search out and prey on aphids, mealybugs, scales and such. They are meat eaters. They don't eat plants, they eat other insects. Not only are there predators which eat their prey (like a lion catching and eating its prey), there are also parasitoids. Parasitoids are almost the same size as their prey, and they always kill the prey insect. A great example of this is the aphid parasitoid. It injects an egg into a live aphid, the egg hatches and the larva begins to feed on the inside of the aphid. The aphid dies. The parasitoid consumes the aphid, matures inside the aphid body and becomes an adult. Then it cuts an exit hole in the aphid and flies out to search for and parasitize more aphids. Aren't you glad you're not an aphid.
The last pest control method is chemical. This is the last resort of pest control and should be used the least. I know our first thought is to run out and buy, mix and spray a chemical, but we must refrain from this and only use this method when none of the other control methods (cultural, physical, biological) have worked. Remember, too, there is no such thing as a pest-free garden and we must allow for some damage.
Even with chemical control, start with the least toxic. These include soaps, oils, diatomaceous earth, insect growth regulators, and Bacillus thuringiensis (Bt), which is a bacteria that kills caterpillars. If these do not work then "harder chemicals" can be used, such as acephate, bifenthrin, carbaryl, etc. Always spot treat – no blanket coverage. Read and follow the label exactly. Use the least amount possible that works. Rotate chemicals by "mode of action". Wear all proper personal protective gear listed on the label. Make sure nothing goes down the storm drain.
When pests are a problem remember the pyramid. Look at your cultural practices first (base of the pyramid). Do you have plants in the "right" places? Are you watering and fertilizing too much, thereby promoting lots of new growth? Next, can you physically remove the pest? Have you given the biological control organisms time to come in and kill the pests? The very last resort would be chemical control.
Article provided by Lavender Pest Control