If you have a short growing season, start seed indoors about 3 weeks before your last frost and set out transplants a week or two after all danger of frost has passed. In warmer regions, direct-seed squashes about the same time you would set out transplants. Generally, your goal is to have your winter squashes maturing in late summer and early fall. Space compact varieties in hills (clusters of several seeds or plants) 1 to 2 feet apart in rows 5 to 6 feet apart. Longer-vining varieties require hills about 4 feet apart and rows 6 feet apart.
Mulches are helpful to keep weeds in check and retain soil moisture. For maximum leaf development, which means sweeter fruits, be sure your squashes get at least an inch of water a week. In very dry regions, grow the C. maxima types, which can survive with flood-style irrigation every two to three weeks.
Use floating row covers to deter insects like cucumber beetles, squash bugs, squash vine borers, and aphids. Remove the row covers when the first female flowers form so they can be pollinated. Aphids, which can transmit viruses to squash, can be problematic (especially in the Southern United States). Try controlling them with soap spray or a blast from the hose. Soap may also help with whiteflies. For larger pests, try handpicking. As a last resort, use neem.
Related: Rodale's Ultimate Encyclopedia Of Gardening
When to pick depends on what you have planted. In general, heed the "days to maturity" number on the seed packet. Each particular type of squash also has telltale ripeness clues. Where a pepo, such as an acorn, a delicata, or a dumpling, touches the ground, it develops an orange spot that darkens as the fruit ripens. Harvest when the color of the spot looks as though "cinnamon has been stirred into the pumpkin pie filling," as Chris Blanchard so poetically puts it. Buttercups, bananas, kabochas, and hubbards have large, spongy stems that turn corky as they ripen. At Rock Spring Farm, Blanchard waits until at least 75 percent of the stem surface takes on this corky texture before plucking fruits from the vine. Butternuts are ready when they turn from their greenish-hued summer color to more of a peanut color. Mature spaghettis, acorns, and butternuts should resist the light pressure of your thumbnail on the skin.
Curing + Storing
Set ripe squashes in a warm dry place to cure for a week or so after harvest to seal the skins and dry out the stems. Then move them to a cool dry place for long-term storage. Unheated rooms or cool cellars work well. Wait about three weeks after storing before you sample them to give the sugars time to develop.