Last week we talked about two aspects of a comprehensive pest management strategy called Integrated Pest Management. This week we build on that by discussing the two remaining elements of IPM; mechanical and chemical controls.

Mechanical Controls

Oftentimes the simple strategies are the best but sometimes the best strategy can also creep some people out. I’m talking about what is called mechanical control. There are various ways to utilize mechanical control and perhaps one of the best and most environmentally friendly is hand picking. For example: you walk out to your garden one morning and see a few cabbage loopers chowing down on your broccoli plant. Many gardeners first instinct would be to visit their pesticide cabinet, select an appropriate chemical pesticide, spray their plants and be done with it. However, a much simpler and equally effective strategy could be used instead: hand picking.

Yes, you’ll probably want some gloves, but with smaller infestations, you could cut off the leaves playing host to the caterpillars, throw them away, and you have very easily made a pretty big dent in your pest population. Other pests such as squash bugs can just be crushed between your fingers. Squash bugs release a bit of a smell when squished but it’s still a very effective way to keep them from destroying your food crops. So, don’t forget about a simple solution: hand picking.

Cages or fences are also effective at controlling pests. Fences can keep larger pests such as deer or rabbits out of your garden and frames covered in chicken wire can keep birds and squirrels away from your strawberries. They even make little bags to cover individual peaches on your tree to keep them safe.

Physical traps such as sticky traps or pheromone traps can also be effective in eliminating pests or at minimum, letting you know when a pest has arrived in your garden. Just place one or more of these traps near your plants and keep an eye out.

Chemical Solutions

The last and hopefully least used pest control strategy in IPM is chemical control. Selecting an appropriate pesticide requires a little bit of an education, but here’s a few suggestions for organic and appropriate pesticides.

Bacillus thuringiensis or Bt is an organic pesticide made from bacteria found in the soil. It is very effective against caterpillar pests. After spraying the plant where the caterpillars are feeding, they will eat the Bt, it will make them sick, and they will stop feeding. Plus, Bt only targets caterpillars so you won’t have any collateral damage from your pesticide usage.

Neem oil is another organic option and is kind of the Swiss Army knife of organic pesticides. Neem oil is made from the oil of the neem tree. As a horticultural oil, just spray the neem oil on the insects and the oil will suffocate them. Neem also has repellant properties to help keep pests away and, it also works well as an anti-fungal on many fungal plant diseases. Be sure to test it in a small area of the plant first just to be safe. Sometimes horticultural oils applied when it is hot can damage the plants.

Insecticidal soap is another great option for organic pest control. Insecticidal soap is just a mixture of potassium salty fats (soap) and water. Insecticidal soap needs to be sprayed on the pest and is quite effective in controlling quite a few insect pests. The soapy water can suffocate them, and it can also disrupt the cellular membranes of the insects by removing their protective waxes. Insecticidal soap is a good option for aphids, some scales, whiteflies, mealybugs, thrips, and spider mites.

On the internet you will read a variety of suggestions on how you can make your own insecticidal soap using dish detergent and water. Just be aware, dish detergent contains a variety of ingredients such as de-greasers, coloring agents, and chemicals to enhance smell, etc. These dish detergent ingredients are not approved for use as pesticides in your garden. True insecticidal soap contains two ingredients; soap and water and is therefore a much better organic choice for your garden.

Other good examples of organic, targeted pesticides are Spinosad and pyrethrin. You can find more information on organic pesticides on our website tulsamastergardeners.org.

As is true with all pesticides, read the label and follow the directions. Each product, even those with identical chemicals, can contain different amounts of those chemicals which determines how they are applied and used safely. So, be sure to read the label so you can utilize the product from an informed place.

There is one last strategy you can utilize as relates to pest control in your garden and that is to take no action against the pest. We always need to remember that the insects that might be causing us grief in the garden are just doing what they do: eating, reproducing, and raising their young. Those destructive caterpillars are just eating their way to adulthood. Sometimes there’s enough in our garden for them and us. We can coexist. Maybe consider planting a little extra so there is enough to share. It’s doesn’t get much more earth-friendly than that. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.

Tomato hornworm: Ward Upham, Kansas State University, Bugwood.org