Blog: Gardening Tip from Sherman Library & Gardens

Are caterpillars treating your garden like an all-you-can-eat buffet? Here at Sherman Gardens it seems like most of the plants we enjoy growing are the same that caterpillars enjoy eating; Geraniums, Lamium, Coleus, Dahlias, and many more.

After all of our hard work we aren't about to give in to their appetite. Tomato Horn Worms are big enough to blow through your summer bounty in a few days, defoliating tomato plants with their voracious appetite. Other tiny inch worms may only bore into your flower buds to graze and keep moving, still leaving damaged blooms in their path.   

Some gardeners are willing or able to tolerate a certain level of damage from these pests, but once the threshold has been reached something must be done to save your garden. You could either invite your friends to a caterpillar-picking-party or use a pesticide. As much fun as the party sounds, applying a pesticide may be easier and involves less planning and finger foods.

At Sherman Gardens we practice Integrated Pest Management (IPM). This means we make our pest control decisions to minimize risks to human health, beneficial bugs, cute critters, and the environment. In this case caterpillars, as cute as they are, are the target of our application. We apply Bt (Bacillus thuringiensis) which is a naturally occurring bacteria that only effects caterpillars. Entomologists (bug scientists) have literally bottled it for use in home gardens. Just spray it on your damaged plants. Once a caterpillar ingests the bacteria it's digestive system is no longer functional and subsequently dies. Its a sad story, true, but its also a safe organic way to control this common garden pest. We like Bt so much we have it available in our garden shop!

Just remember the larva of a monarch butterfly is also a caterpillar! So be mindful when you apply Bt.

Happy Gardening!