Winter Squash, Pumpkins, Summer Squash & Zucchini

Cucurbita spp.
Refer to the Species Guide below.

Please note that pumpkins are a type of winter squash and zucchini are a type of summer squash.

Summer Squash & Zucchini varieties
Winter Squash varieties
Pumpkin varieties

Culture: Culture of squash and pumpkins is similar to that of cantaloupe and cucumber, which are also members of the squash family. Squash and pumpkins require warm days and warm nights to mature properly. Sow seeds 1/2 to 1" deep. Bush varieties should be spaced 18-30" apart in rows 4' apart, or 6-8 seeds per hill, in hills 4' apart. Vining varieties are planted in rows or hills 6-8' apart. Keep soil moisture high by mulching, but do not apply organic mulch until the days are warm.

Harvesting Summer Squash: Harvest crooknecks and zucchini when 6-8" long. Zucchinis will grow large enough to become “attack zucchinis" if you don't keep them harvested.

Harvesting Winter Squash (Pumpkins): Winter squash is ready for harvest when the rind loses its shiny luster, becomes duller, and can no longer be dented by a fingernail. After fruits have matured 10-15 days past the ripe stage, harvest by cutting stems 1" above the fruit. Do not allow fruits to become frosted. Store at 45-60°F (7-16°C) and maintain good air circulation.

Diseases: In the mid-Atlantic, squash may be affected by downy mildew, powdery mildew, bacterial wilt, and blossom end rot. Powdery mildew occurs during hot, dry spells, whereas downy mildew occurs during wet, cool spells near the end of the growing season. Bacterial wilt causes sudden dramatic wilting and death of the vines. Use resistant or tolerant varieties, practice good sanitation and crop rotation, and pay attention to proper growth requirements. To prevent blossom-end rot, supply adequate calcium and maintain even moisture.

Pests: Mix charcoal into soil just before planting to reduce vine borers. For small varieties another strategy is to pinch growing tip(s) when vines are 1-2 feet long. This creates multiple vines, increasing odds of escaping borer damage. Use pyrethrum or sabadilla to control cucumber beetles and squash bugs. Destroy eggs of the squash bug by squashing by hand, or deposit eggs in a jar of soapy water. To trap squash bugs, place boards around the plant bases. Squash bugs will hide under the boards at night and can be collected in the morning. Vine borers can be cut out of stems by making a cut along the length of the stem and removing larvae of the borers. Some additional protection from borers may be obtained by applying rotenone around the base of the plant. Keeping plants under row cover until flowering extends plant survival. For non-resistant varieties a succession of plantings may be required to establish a crop. Use resistant varieties where possible.

Seed Savers: There are 4 species of pumpkins and squash. The species is listed in parentheses beside the name of each variety. Crossing occurs easily within a species and rarely between species. Isolate varieties of the same species by a minimum of 1/8 mile if you save seed for home use. Pure seed requires hand pollination or a minimum isolation of 1/4 to 1 mile, depending on planting size.

Summer Squash Packet: 3-4 g (approximately 25-60 seeds, average 35 seeds)
Winter Squash (Pumpkin) Packet: 2-6g (approximately 20-50 seeds, average 31 seeds).

Species Guide

C. pepo: Pepos are usually eaten in the immature stage as summer squash (or zucchini). The flesh is often mild flavored and usually prepared by boiling, baking, frying, or stir-frying. Most varieties are not good keepers - Acorn squash is a Pepo that is eaten as a winter squash, but it does not store well. Quality of the flesh declines in storage and most varieties are best eaten within a month of harvest. Bush varieties of C. pepo are susceptible to vine borers and are best planted in succession. Try luffa gourds or Tromboncino (a Moschata) as a bug-proof substitute for zucchini.

C. maxima: Many members of this group grow quite large. They keep fairly well in storage, from a few months to a year or more, depending on the variety. The flesh has fine texture and very good flavor. Unfortunately, Maxima are generally sensitive to wilts, vine borers, and other insects, and so may not thrive in hot, humid areas. These are the best choice for those growing winter squash in mild climates with few disease or pest problems, as they do not require warm nights to be productive.

C. moschata: Most Moschatas are excellent keepers. Their flesh is usually orange in color, flavorful, sweet, and often fragrant. Moschatas are well suited for pies and cakes, though they are often baked or boiled. This species generally has good resistance to vine borers and cucumber beetles once the plants are beyond the seedling stage. During the growing season, Moschatas need warm night temperatures above 60°F (16°C) for best - they are an excellent choice for warmer climates.

C. argyrosperma: Squash of this species, also known as Mixtas or Cushaws, have a long tradition of being grown in the South, though they are less popular than they were in former years. Flesh color is typically pale-yellow or cream-colored and somewhat coarse. They are not as sweet or flavorful as Maximas and Moschatas. They are often cooked with sweeteners such as brown sugar or baked with stuffing mixtures. South of the border, most are grown mainly for their large, flavorful seeds. Like Moschatas, they have good resistance to vine borers and cucumber beetles. The best drought tolerance of all the squash species - ideal for hot, arid regions and dryland gardening.

Summer Squash & Zucchini varieties
Winter Squash varieties
Pumpkin varieties

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