Preventing Squash Vine Borer Damage
Nothing is more discouraging than walking into the garden and finding your zucchini or other squash plants have suddenly wilted. A close look at the base of the stem reveals damage and sawdust like material, indicating squash vine borers have moved in.
You can reduce the risk by covering new plantings with floating row covers. These fabrics allow light and water through but prevent the adult squash vine borer moth from laying the eggs at the base of the plant.
Don’t use row covers when planting squash in the same location as the previous year. Since the squash vine borer overwinters in the soil near squash plants, the row cover will trap the insects by the plants providing easy access.
Remove the row cover as soon as the plants begin to flower so the bees can reach the flowers and pollinate the plants for a tasty harvest.
A bit more information: Once the borer has infested the plants leave it in place. Slit the stem lengthwise until you find the borer inside. Kill the borer and cover the slit stem with moist soil so it can form roots.