If you’ve ever grown zucchini, then you know that it is a generally easy to grow, reliably prolific producer – as long as you can keep pests away, of course. Early frosts can also dash your hopes for zucchini bread and other squash treats. In the following article, we’ll discuss how to protect zucchini squash, both by keeping pests off zucchini and frost protection of zucchini.
How to Protect Zucchini Squash from Frost
Some crops, like cabbage, peas, carrots, and parsnips, will tolerate a little frost, but zucchini is a warm-season crop that can be injured by cold temps. If you are in a region where early frost is imminent, frost protection of zucchini is integral to its survival. It is important to ensure that you wait for all chances of frost to pass in your area before planting. That said, Mother Nature occasionally has other plans.
When it comes to zucchini plant protection, you can cover the zucchini with straw, plastic, newspapers, or old sheets. The goal is to trap the heat from the soil into the air immediately surrounding the plants. In the morning, remove the covering so it won’t trap the sun’s heat and kill the plants. Keep in mind, however, that this will only work if you have a very short, very mild frost.
Mature plants with fruit on the vines may need to be harvested immediately.
Protecting Zucchini Plants from Pests
You aren’t the only one that relishes the zucchini. Any number of critters are vying for their share of the spoils. The usual suspects are insect pests, of course, but birds and rodents will also gnaw at the fruit.
Netting set over your squash crop will help deter squirrels and other rodents, but keeping the insect pests off zucchini requires a more cunning approach. Sure, there are always insecticides, but keep in mind that if you go that route, you are more than likely killing off the beneficial insects too. Beetles, aphids, borers, and caterpillars are all waiting with bated breath for you to turn your back on the squash vines, so it’s important to have a zucchini plant protection plan of attack.
Squash bugs are one of the more damaging insect pests on all types of squash. As the adults and juveniles feed, they inject a toxin into the plant that causes it to wilt and die back. Look for the adults on the backside of the squash leaves, often accompanied by clusters of small, oval, orange eggs. Their offspring look quite different from the adults, more spider-like. Both the adult and nymphs can be hand-picked off the undersides of the squash leaves and drowned in a bucket of soapy water. The eggs can then be gently scratched off and disposed of in the same way.
Squash vine borers are native to the eastern portion of the United States. The adults look like a wasp but are actually a type of moth. They hover around in the late spring to early summer looking for a likely squash upon which to deposit their eggs. The resulting offspring hatch within a few weeks. These caterpillars enter the stem of the squash and feed on it for 4-6 weeks until the plant dies. Again, these pests can be handpicked if they’re not too severely damaged. Slit the stem of the plant carefully and remove the grub by hand.
If just the thought of hand picking grosses you out, a better plan of attack is to thwart the adults. Use row covers, a non-woven fabric cover, to keep the adults from laying their eggs. They can be tacked down if you prefer or just draped over the plants where they can be easily removed for watering purposes.
There are also other ways of protecting zucchini plants from insect marauders. Some folks place small strips or squares of aluminum foil around the base of the plants to repel squash bugs.
Diatomaceous earth can also be used. It is made up of the skeletal remains of minuscule sea creatures and although it looks powdery, it will actually cut up the soft bodies of insects.
Apparently, you can try luring squash bugs away with the color yellow, as these bugs supposedly have a penchant for the color and if you paint or place something yellow nearby (but not too near the vines), they will flock to the lure. Hanging yellow plastic tape or ribbon works well and is even better if you include some sacrificial squash plants under the ribbon.
If all else fails and you’ve just had it, the big guns can come out. I mean insecticides. For squash bugs, insecticides are only effective against the nymphs and should be sprayed immediately as soon as eggs are spotted on the leaves. Cover the backside of the leaves well with the spray and repeat every 7-10 days as long as eggs and nymphs can be found. For the control of squash vine borers, apply insecticide to the stems of squash plants near the base every 7 days from late May through June.
For both insects, synthetic pesticides include esfenvalerate, permethrin, bigenthrin, and Sevin controls just squash vine borers. For an organic approach, try applying neem oil. It does need to be applied more often (every 3-5 days) than the synthetic insecticides, but it is safer for our friends, the honeybees – and us.