I am growing butternut squash on big pots in full sun and every flower gets a worm inside and all the fruits end up rotten.

Here are some solutions that we hope will help you to control and eventually eliminate your pests and use IPM – Integrated Pest Management practices that we recommend within our college.
For your butternut squash: You have squash vine borer, which is one of the most common pests encountered when growing most all squash. They are active during the day and generally lay their eggs at sunset. The worms you are finding are the larvae which has come from the adult moth that has laid eggs at the base of the stems.
Method to control:
- Till the soil around the plant to expose any larvae and remove them putting them in water to submerge them.
- Inspect your plants for any eggs, moths and worms and of course, remove them.
- Spray plants with an organic insecticide of Bacillus Thuringiensis (BT). BT is a species of bacteria that lives in soil. It makes proteins that are toxic to insects when eaten, but not to humans or mammals. BT has been used safely for over thirty years to control insects that causes toxicity in caterpillars. You can fine Bonide Caterpillar and Worm Killer (BT) in a 32 oz spray that is ready to use at Home Depot, Lowes, and on Amazon for about $14.00.
- The adult moths are attracted to the color yellow. Surround the garden with small yellow pails half filled with water.
- Give your squash a good organic fertilizer, like manure or compost to keep the plants healthy and strong to combat any nutritional drain from the vine borer.
Having pests in the garden is never easy and can be extremely frustrating! But, with a little perseverance and tenacity, they can be controlled.
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