In last Tuesday’s article we began a discussion about how to have your healthiest, most productive garden yet by utilizing a multi-step process called Integrated Pest Management (IPM). Last week we talked about cultural and biological controls. This week we continue with the remaining two steps in the process: mechanical and chemical controls.

The simplest use of a mechanical control strategy is accomplished by hand removal of the pests. Here’s an example. Let’s say you go out to your vegetable garden one morning to water and notice your cabbage plants are showing signs of cabbage looper damage. Cabbage loopers eat holes in the leaves, so if you start to see holes in the leaves of your cabbage plant, there are probably cabbage loopers present.

To deal with this issue, rather than immediately heading toward the organic pesticide cabinet, first inspect your plants to determine the degree of infestation. Many times you can just cut off the leaves playing host to the cabbage loopers and dispose of them. Or you can put on your garden gloves and pick off the loopers. Problem solved.

A slight variation of mechanical control works for squash bugs and involves you squishing the bugs between your fingers. Just know, squash bugs give off a rather unpleasant smell when crushed.

Cages or fences can also work when trying to control larger pests such as rabbits or deer. And smaller protective frames covered with chicken wire can help keep birds and squirrels away from your strawberries etc.

There are also physical traps such as pheromone traps that will help attract the pests to the sticky trap where they will be unable to get away. Oftentimes these pheromone sticky traps can be a first indicator of a pest in your garden. Now let’s talk about chemical solutions to pest problems.

Knowing which organic pesticide to use and how to use it to address a particular pest issue requires a bit of education but here’s a brief overview to get you started.

If you have determined you have some sort of caterpillar eating your vegetables, Bacillus Thuringiensis (aka Bt) is a good choice. Bt is an organic pesticide made from bacteria found in the soil and it is very effective against caterpillars. After you spray the plant being devoured by caterpillars, the caterpillars will eat the Bt which causes them to stop eating. Bt is only effective on caterpillars, so there’s no need to worry about collateral damage to pollinating insects in your vegetable garden.

Neem oil is another organic pesticide option and what I call the Swiss Army knife of organic pesticides. Neem oil is made from the oil found in the seeds of the neem tree. As is true with most horticultural oils, you just spray the oil on the insects and as a result they suffocate. However, neem oil also has some repellant properties in addition to it also working as an anti-fungal. When using neem oil, be sure to test it on a small part of the plant first before applying to the entire plant. Do this especially as we enter summer as horticultural oils combined with heat can sometimes damage plants.

Insecticidal soap is another option for organic pest control. Insecticidal soap contains two ingredients: potassium salty fats and water. It works in a couple of different ways. First of all, it suffocates its intended target but it can also disrupt the cellular membranes of insects by removing protective waxes. This product is a good option for aphids, some scales, whiteflies, mealybugs, thrips, and spider mites.

Now is the time I get up on my soapbox a little bit. The internet is a great place to learn all kinds of information… both good and bad. Online you will find an abundance of recipes for making your own insecticidal soap from dish detergent. The problem is that dish detergents contain a variety of ingredients including de-greasers, coloring agents, and chemicals to enhance smell and sudsing of the product. These ingredients are not approved for use as a pesticide in your garden. As I said earlier, insecticidal soap contains two ingredients: potassium salty fats and water. Because of that, it is a much better organic choice for your garden.

There are a variety of other organic pesticide including spinosad and pyrethrin. We have information about these on our website in the Lawn and Garden Help section/pesticides.

Whenever you use a pesticide, be sure to read the label first and follow the directions. Even though a product may say it contains the same pesticide as another product, odds are they are not in the same concentration of ingredients, so it is important to read the label to know how to use this particular product. Bottom line - be informed.

Personally, I like to add a fifth aspect of IPM to the mix: you don’t have to do anything when confronted with a pest issue. In many instances, the pest that is causing you issues is transitory and will soon be leaving your garden. If you can stand the pain of watching them munch away on your vegetables, a perfectly acceptable option is to just live and let live…maybe even plant a little extra so there’s enough for everyone. That sounds pretty earth-friendly to me.

If you would like to learn more about IPM and other topics related to growing vegetables, we still have spots available in our final Urban Gardener/Seed to Supper class of the year on July 22^nd. Just visit our website for more information and to sign up. 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.  Photo: Tom Ingram