Does your plant look like the zucchini in the above picture? Once lush and huge, this zucchini took a turn for the worse. What happened? Zucchini can be damaged by several forces. Since it’s the plant that feeds my family throughout the year, I take personal offense to these attacks from mother nature! However, I grow our food organically, and do not use insecticides or fungicides. The most damaging to zucchini is squash vine borer. Other attackers are squash bug (lays small, hard, brown eggs on underside of plant that hatch into brown triangular-shaped insects) and powdery mildew (a white fungus that grows on leaves).
Today I’m focussing on squash vine borer, the insect that just wiped out my zucchini 🙁 Who are they? They are the larvae of the squash vine borer. The adult squash vine borer lays its eggs in the soil at the base of squash plants. Once the eggs hatch, the larvae bore into the base of the plant where they feed on the inside of the squash plants. They suck the moisture and structure out of the plant, leaving it weakened and eventually will kill the plant. I didn’t get to it soon enough, and it weakened my plants too much. However, if you notice its warning signs early enough, you can prevent it from destroying your plants.
Warning Signs You’ve Been Attacked By Squash Vine Borer:
- Pierced holes on stems or at base of plant
- Browning of the plant at the base, almost mush-like/sawdust consistency
- Wilting leaves of zucchini
What can you do? To prevent the problem from happening in the first place, you can spray an oil on your plants called neem oil. Neem oil is made from the seed of the neem plant, a natural fungicide and pesticide. It helps to coat the leaves and stems of plants to prevent disease. Be sure to dilute it and spray it in the early morning or early evening, to prevent the plant from burning in the hot sun. This is the Neem OilI buy through Amazon.
Another option for prevention is to use yellow trap pans to detect squash vine borer adults. Take any container (e.g. pan, pail, bowl) colored yellow and filled with water. Because squash vine borer adults are attracted to yellow, they will fly to the container and be trapped when they fall into the water. Place traps by late June, checking your traps at least once a day. You can also place covers over the plants in late June to prevent the borers from getting into the plants.
If you’ve been attacked, as I had (I didn’t motivate early enough to spray my plants 🙁 ), the only solution is to cut out the culprits. How? Well, I’m not going to lie. It’s pretty gross. You take a knife to the base of the plant, and make an incision where you see the browning occurring. If you see damaged leaves, break those off too, since there’s probably larvae living where the stem attaches to the base of the plant. Once you’ve cut open the affected area, remove any larvae you see in the plant. Do this with a container of soapy water nearby, so you can drop the larvae in it. If you look in-between the area I cut below, you can see the larvae in the holes they have left behind. DON”T compost this!!! The larvae will mature and grow into adults who will then lay eggs into your compost.
To help prevent future attacks, rotate your crops, so that you’re not planting squash family plants in the same area next year. This helps to confuse the insects, and decrease incidence.
Here’s my video further explaining the squash vine borer.
If you manage to still harvest a lot of zucchini, I have a bunch of recipes using my favorite fruit! Search my site for zucchini and you’ll be lead to a bunch of recipes (more always coming down the line). Here’re two to start:
Happy growing and eating!