Although prevention is in the beginning of insect control(companion planting, cleanliness, healthy and disease resistant plants), insecticides can come in handy at some points. With that in mind I developed this short guide to insecticides to help you choose the one which is best for you, but at the same time remembering the toxic nature of some insecticides. So this guide progresses from the less toxic, homemade insecticides (which can be very beneficial with small or beginning infestations) to the more powerful pyrethrum and insecticidal soaps.
Many of the homemade pest repellent mixtures can be very effective against garden pests. Strong hot tastes or smelly odors are common characteristics of most home-brewed pest repellents. Most sprays are just repellent plants(plants that repel insects while growing) blended with water and strained through cheesecloth or nylon mesh, leaving a basic repellent tea. The tea is then diluted in water to concoct a spray. The sprays are not usually cooked due to the fact that heat generally destroys the active ingredients. Instead the repellent plant is dried and minced, and allowed to soak in mineral oil for a couple of days. This is then added to water including a little detergent or soap to suspend the oil on top the water, and a teaspoon of alcohol per quart to help dissolve the soap.
There are hundreds, maybe even thousands of good homemade insect repellent recipes that you can find in books and on the internet. The following are a few I have found work best in my garden: