I’ll tell you, growing squash can really teach you about guerrilla warfare in the garden. It seems as though just about everything is out to get your gourds, and if you don’t like resorting to pesticides that kill the good bugs (think bees, ladybugs, praying mantis and butterflies) along with the greedy, pesky bad bugs, you can have a daily struggle on your hands.
In my ongoing effort to protect my zucchini plants (I planted some charming round ones this year), birdhouse gourds and other squash varieties, I’ve tried these tricks with varying success. In any given year, some tactics seem to work better than others.
Zucchini Tips and Tricks
Use aluminum foil – Place small strips or squares of aluminum foil around the base of the plants. It repels squash bugs. It won’t get all of them, but every little bit helps. This works with cucumbers, too.
Dust with diatoms – Diatomaceous earth looks like powder, but from a bug’s perspective, it’s really a pile of very tiny razor blades. It slices up bug bodies as they crawl around your plants. It’s pretty safe to use. (It may cause skin reactions and you should strap on a mask before apply it.) Dust diatomaceous earth around the base of your squash plants to discourage vine borers (slugs and snails, too). It’ll last until the next drenching rain. Diatoms are the skeletal remains of minute sea creatures. You also see them used as a super effective filtering medium.
Use companion planting – I think of this as the art of placing a plant bugs hate next to plants they love. For squash, I interplant with marigold, lavender, dill and catnip. I also whip up bug sprays using those and other herbs. The idea is to make the squash plants so fragrant with other aromas that vine borers (and others) won’t smell them and decide to lay their eggs in the middle of your crop.
Catnip grows fast and tall in my garden, and long about the beginning of July, I start pruning it back and sticking the stems among the squash plants for extra insurance — just a suggestion.
Use row covers – This nonwoven fabric is available in 25 and 50 foot lengths (by 5 to 6 foot widths). It’s very sheer and gauzy, but many bugs can’t get through it or find their way around. You can leave row covers in place and tack them down for added security, but I find that’s more of a hassle that it’s worth. I drape the fabric over my squash plants in the evening and take it off before I water in the morning. The idea is that vine borers and some other nasties shop for new real estate late in the day. If you cover plants then, you’ll be keeping them safer during the riskiest time. You can buy a 5 ft. by 25 ft. length of row cover fabric for around $12, and it’s cheap at the price. If you don’t poke too many holes in it, you can use it year after year.
Water in the morning – If you’re having problems with powdery mildew, avoid getting plant leaves wet just before the temperature drops in the evening. Water in the morning instead, or water around the bases of your plants and keep the leaves as dry as possible.