Q: Our squash plants are small and we have covered them with cheese cloth. How long should we keep the plants covered to protect them from the squash vine borer?
A: Squash vine borer causes much gnashing of teeth for metro gardeners. Plants look healthy until just before squash is produced then the whole thing rots at the base of the stem.
A moth lays her eggs on the stem when the plant is young and the larvae bore into the squash stem. The moth looks vaguely like a wasp. About an inch long, it has an orange-red body and dark, fuzzy wings.
Cheesecloth will get very heavy when wet, not the best material to use. A better, low cost way to prevent borers is to cover plants with floating row cover (click for sources), a lightweight material made from spunbonded polyester.
Cover the squash row immediately after the plants sprout, anchoring the fabric edges with soil. Use a series of upright sticks to hold the fabric off of the plants. Remove the row cover when the squash begin to bloom, to allow pollinators to visit the flowers.