If you’ve grown squash plants in your home gardens, be they pumpkins, zucchini, or butternut squash, you may have dealt with squash borers and not even known it. Have your plants ever wilted seemingly overnight? Have you seen big, mushy holes in the plant stems? That’s a sure sign that you have squash borers. Here are a few tips on how to avoid these highly destructive pests so you can produce a bountiful harvest from your summer squashes and winter squash plants.
Squash borers are the larvae form of a certain type of orange and black moth about an inch long that is active by day. Many people may recognize these adult moths as wasps because they have a similar look; but they’re not wasps, in fact, the adult squash vine borer is a moth.
In early July adult moths begin looking for host plants on which to lay squash bug eggs. They lay shiny copper eggs on squash stems at the base of the plant, or sometimes on the leaves themselves. Once the eggs hatch borer larva emerge and eat their way into the stems of squash and pumpkin plants. They reside inside the plants, eating away at the stems until the next phase in their life cycle happens and they become moths, starting the whole thing over again.
There are a few tricks you can try to prevent squash borers. When the plants are young you can wrap the stems in aluminum foil to inhibit the moth’s ability to access the base of the plant. As the plants age, you should loosen these wraps so as not to strangle the plants.
Floating row covers that cover the entire plant will keep squash borer moths off your plants and interrupt the life cycle.
Some people place yellow bowls filled with water and a drop or two of detergent near the plants to lure the moths and drown them.
Another tactic is to mulch the stems; this will help support the plant and prevent the moth from reaching the stems.
The best way to prevent squash borers is to spray BT (beneficial bacteria spray) on the base and stems of the plant once a week. BT is a naturally occurring bacteria that ONLY kills caterpillars and eggs. It does not harm beneficial insects like bees. By using BT, any borers will quickly be killed before they can munch on your squash garden. BT is considered organic and many organic farmers use BT spray.
Whichever method you choose (or even if you do several) remember to keep your squash well-watered. They’re big drinkers and if they’re weak from dehydration they’re more easily susceptible to being infested with pests. Follow these tips and you’re sure to have a bountiful season’s harvest!