Grow Guide Conditions:
Squash and pumpkins are frost sensitive, heat loving crops. They grow best on well drained, fertile soils with a pH between 6.0-7.5. Supply consistent moisture with drip irrigation to reduce mildew and other foliar diseases. For winter squash and pumpkins, reduce watering as fruits near maturity.
Grow Guide Seed:
Squash are most commonly direct seeded, although transplanting is possible in short season areas. Optimum soil temperature for germination is 70-85°F, but seeds will germinate at temperatures as low as 60°F. Direct seed 2-3 weeks after the last spring frost when weather is warm and settled. Plant seed 1 inch deep, 3 seeds grouped together every 18-24 inches, allowing 24-36 inches between rows for squash; or 24-36 inches apart and 36-60 inches between rows for pumpkins. Thin to one plant per spot. To start indoors, fill 4 inch pots with a sterile seed staring mix. Plant 2 seeds per pot and thin to one plant by snipping off the weaker seedling at the soil level. Harden-off seedlings for 5–7 days prior to transplanting. Squash do not like having their roots disturbed, so transplant 3–4 week old seedlings outside carefully after the last frost.
Grow Guide Pests:
Practice 3 year crop rotations among all Cucurbit family crops (cucumbers, melons and squash). Foliar diseases such as Powdery and Downy Mildew, Alternaria Blight, and Angular Leaf Spot can be minimized by using drip irrigation and mulching to minimize splash-dispersal of spores. Spray young seedlings with insecticidal soap, pyrethrins and neem oil, or cover with floating row cover, to prevent cucumber beetle damage and the bacterial wilts they can vector, but uncover plants during flowering for pollination. Control aphids to prevent mosaic virus. Squash Vine Borers can be ‘surgically’ removed from the stems. At the first sign of wilt, look for the sawdust-like ‘frass’ at the entry hole and cut parallel to the stem to extract and crush the worm. Use a twist tie to loosely seal the wound, bury the stem, and hope the plant survives. See our merchandise section for related products.
Grow Guide Harvest:
Winter Squash: Harvest when vines have begun to die back and fruit has reached its full size and final color. Cut fruit from vines leaving a 1-2 inch stem for good storage. Store at 50-55°F in a dry place. Bring in before the first frost to avoid chilling damage that reduces storability.