Hillside Greenhouse

Insect Pests

Occassionally, you may have problems with a few insect pests. Most aren't serious and are fairly easy to control with only a little work . Insects are a part of nature and can never be completely eradicated. Many insects are actually beneficial and should not be sprayed. For example, most insecticide labels restrict spraying when honeybees could be adversly affected.

These days, people are more likely to want to use environmentally friendly chemicals in their gardening, which is a great idea. There are a lot of options to control insects while not causing any undue harm to the environment. But remember that even naturally occuring chemicals can still be hazardous, and caution is always the rule of the day. Such compounds as pyrthrins, which are "natural" compounds are still toxic and must be handled carefully.

White Fly and Aphids

The most common insect problems you will likely encounter are white fly and aphids. Both live on common garden plants and suck the sap for nutrients. Both are also controlled quite well with insecticidal soap.

Insecticidal soap is inexpensive, safe, and easy to use. Mix it to the manufacturers directions. It's usually best to mix with soft water or clean rain water. Make sure it is well mixed and apply it directly to the plants with a sprayer. Avoid using on very hot days. You need to get good coverage of the insects to kill them. The soap is essentially harmless to people and pets and is usually labeled to be used right up until harvest of vegetables.

You can purchase insecticidal soap from many sources, but many people make their own by mixing one or two tablespoons of Ivory Dishwashing Soap into a quart of water. Commercial insecticidal soaps have an additive to make the spray sticky, but the home-made version is reported to work just as well.

You may sometimes notice heavy infestations of white fly on tomatoes. It's best to control the problem before it gets too bad, but even if there are a lot of white fly, a couple applications of soap over a three or four day period will quickly reduce the population. Tomatoes also seem to be quite tolerant of white fly, so seeing a few of them around is no reason to panic -- just treat with soap and the problem should soon be resolved.

Other Sources of Information

The University of Minnesota Extension Service maintains a number of factsheets and other information related to insect pests. Click the button below for more information.