Native Americans called it isquoutersquash. The British call it marrow. Squash is the American English term.
Zucchini, summer squash, winter squash, and pumpkins grow best once the air temperature averages 65ºF (18ºC). That means squash can be sown in late spring just about everywhere, and if you live in a long growing season region where the weather turned warm six weeks ago, you may be on to your second planting of squash, perhaps a second variety.
Most summer squash require 50 to 65 frost free days to mature. That means you can safely plant squash in the last week or two of spring. Winter squashes take a bit longer: 60 to 100 frost free days to mature. You can still sow winter squash seeds in late spring and get to harvest before the first frost in most regions.
Tender summer squash can be eaten raw or cooked. If you got an early start on your squash this year, you may already be adding sliced raw young squash to salads. Winter squashes are drier and more fibrous than summer squashes. Winter squashes are harvested when fully ripe and require cooking. Get them growing before the official start of summer arrives.
The requirements for planting and growing summer and winter squashes are the same except for the time required to harvest.
Site. Squash require full sun, warm weather, and good air circulation to mature. Squash grows best in growing zones 3-10. If your growing season is short, choose a bush variety squash which will mature more quickly.
Soil. Plant squash in humus-rich, well-drained soil; work in organic compost the autumn before planting or spread compost in the growing bed during the growing season. Bush-types varieties can be grown in containers.
Squash Planting. To get a jump on the season, start summer and winter squashes indoors 3–4 weeks before the last frost. Sow squash outdoors or set out seedlings when the soil temperature reaches 70ºF (21ºC). Sow seed ½ inch–1 inch (13mm–2.5 cm) deep. Thin successful plants to 36 inches (90 cm) apart in all directions.
Squash is often planted on slight mounds or hills. Sow 4–5 seeds 2–3 inches (5–7.5 cm) deep, 3–4 inches (7.5–10 cm) apart in hills raised 12 inches (30 cm) spaced 6 or more feet (1.8–2.4 m) apart. Thin to 2 successful plants per hill. If plants are supported on wooden tripods space hills 4 feet (1.2 m) apart.
Watering Squash. Squash requires regular and even watering. Keep the soil just moist. Avoid overhead watering.
Feeding Squash. Squash are heavy feeders; apply lots of compost to the soil and they should do well. You can feed squash with compost tea every couple of weeks during the growing season.
Companions. Grow squash with celeriac, celery, corn, nasturtiums, melons, onions, radishes, peas, and beans. Avoid growing squash with potatoes.
Squash Pests. Aphids, cucumber beetles, squash bugs, squash vine borers, and other insects can all attack squash. Use rows covers to protect young plants from cucumber beetles and squash borers; remove covers when the plants bloom. Clean up refuse at the end of the season, and turn the soil in spring to bury insect pupae.
Squash Diseases. Bacterial wilt, mosaic virus, mildew, blight, curly top are viruses and fungi that can plague squash. Control disease-spreading pests; plant disease resistant varieties, and remove and destroy infected plants.
Squash Harvest. Tender summer squash can be harvested when the rind is tender and before the seeds have developed. Summer squash should be harvested 2–3 times a week once plants begin bearing. Break fruit from the plant, or use a knife. Clean your knife after each use to avoid spread of disease to other plants.
Allow winter squashes to mature fully on the vine until their skins are extremely hard before harvesting. Harvest winter squash before the first frost. After harvest, winter squash should be allowed to cure outdoors; dry and toughen the skins by exposing winter squash to sun for 5–7 days or place the squash in a cool, dry ventilated area for 5–6 months.
Summer Squash Varieties. Summer squash varieties include scalloped squash or patty pan, yellow crookneck, straightneck, cylindrical, green or gray zucchini, and Italian squash.
Winter Squash Varieties. Winter squash varieties include acorn, banana, buttercup, butternut, cushaw delicious, hubbard, marrow, spaghetti, turban, and pumpkins.
More tips: How to Grow Squash.