Gardening in Poway: How I Got Rid of Those Caterpillars Eating My Leaves

By C.H. Currier

It was warmer than usual for an early September morning. The sun wasn’t up yet, but I could see the Poway Chieftain in its plastic wrapper at the top of the driveway. I filled my lungs, rolled my shoulders, and cracked my knuckles before stepping off the porch to retrieve the week’s news. I followed, along with my eyes, the sound of a kingbird, high in my neighbor’s ash tree. These birds are always the first ones awake to sing their morning songs full-throated. It felt like it might be another good day in Poway.

At the same time, I also felt like something was wrong. I used to run a landscape company. It was my job to see the things my employees missed. I scanned the yard with a quizzically scrunched face. Nothing seemed obvious. Droplets on the shrubs indicated that the sprinklers had been on that night as scheduled. The forty-foot Ginkgo had turned yellow a little early but all the others in Green Valley were doing the same. The fifteen-foot tall Red Bud, growing next to the Gingko, contrasted nicely with its rich green foliage. I shrugged and continued along the driveway to get the paper. Then I saw it. The backside of that same Red Bud had entire patches nearly devoid of leaves. Although the air was still, twigs and branches were rustling ever so slightly. I stepped closer. An army of caterpillars was devouring my tree leaf by leaf, stem by stem.

What would repulse most homeowners tends to fascinate me. Like witnessing a slow-motion car wreck, I watched how each spiked two-inch green eating machine did its work. Some were crawling from branch to branch. Others were wound around each other, one eating the edge and the other eating the middle of a juicy heart-shaped leaf. Within minutes they too were moving on to greener pastures.

 My training as a horticulturist kicked in and I started making mental notes about what weapons I had in the garage to repel these invaders. If it’s a gigantic three-inch tomato hornworm or a beefy grasshopper I will grab my trusty BB gun and plink them. That’s about the only true hunting allowed within the Poway city limits, so I savor those moments. This situation required a different sort of response. Now that the sun was up, I could see that there were hundreds of these critters munching all over the tree.

I considered my options. In another month these leaves would turn color and begin to drop off naturally anyway. I asked myself what’s to gain by killing my uninvited breakfast guests. Their poops are a natural fertilizer. A few birds, like blue jays or mockingbirds, might have an excellent buffet. Defoliation of this tree surely wouldn’t kill it. If I spray a toxic chemical, might I not kill a lot of other hidden beneficial insects and perhaps predators? Probably. Besides, all those poisons smell bad, and I’d have to wear protective clothing and a respirator. I nearly walked away.

I am a male human being. I am being challenged by mother nature. This was kicking sand in my face and even though I knew better, I couldn’t let this go. The only question was how to do it properly and safely. The answer was BT. No not BT phone home, Bacillus thuringiensis, a naturally occurring bacteria that only affects caterpillars. It comes in a liquid and is safe to use even in organic gardens. I had some in the cupboard and it was time to put it to use. I filled my pistol-grip hose-end sprayer with the slurry and a few drops of dishwashing detergent and sprayed the entire tree. It takes a day or two but even though the buggers don’t immediately die they do stop eating. The bacteria cause their stomachs to crystalize, and they starve.

 I’m too caught up in my ways. I couldn’t do “live and let live.” Maybe if they were cuter, I could have. There’s something about worms and hairy caterpillars and snakes that affect most humans in a scrunched-up face kind of way. I guess, push come to shove, I’m one such human.

C.H. Currier is a thirty-year resident of Valle Verde, a retired horticulturist, and a published short story writer. Look for his upcoming novel, Where the Ashes Fell, in 2022.