Summer squash appears in many different fruit shapes and colors:
- Scallop or Patty Pan is round and flattened like a plate with scalloped edges, usually white but sometimes yellow or green.
- Constricted neck is thinner at the stem end than the blossom end, classified as either "crookneck" or "straightneck" depending on if the stem end is straight or bent, and is usually yellow.
- Cylindrical to club-shaped Italian marrows, such as zucchini, cocozelle and caserta, are usually shades of green, but may be yellow or nearly white.
The varietal selection of summer squash has markedly changed in recent years and the number of varieties offered has greatly expanded as the result of new interest, hybridization and introduction of disease resistance. The number of varieties is staggering. Recommended varieties of summer squash include:
Zucchini (Open Pollinated)
- Black Zucchini (best known summer squash; greenish black skin, white flesh)
- Black Beauty (slender, with slight ridges, dark black-green)
- Cocozelle (dark green overlaid with light green stripes; long, very slender fruit)
- Vegetable Marrow White Bush (creamy greenish color, oblong shape)
- Aristocrat (All America Selection winner; waxy; medium green)
- Chefini (AAS winner; glossy, medium dark green)
- Classic (medium green; compact, open bush)
- Elite (medium green; lustrous sheen; extra early; open plant)
- Embassy (medium green, few spines, high yield)
- President (dark green, light green flecks; upright plant)
- Spineless Beauty (medium dark green; spineless petioles)
Golden Zucchini (hybrid)
- Gold Rush (AAS winner, deep gold color, superior fruit quality, a zucchini not a straightneck)
- Early Yellow Summer Crookneck (classic open-pollinated crookneck; curved neck; warted; heavy yields)
- Sundance (hybrid; early; bright yellow, smooth skin)
- Early Prolific Straightneck (standard open-pollinated straightneck, light cream color, attractive straight fruit)
- Goldbar (hybrid; golden yellow; upright, open plant)
- White Bush Scallop (old favorite Patty Pan type, very pale green when immature, very tender)
- Peter Pan (hybrid, AAS winner, light green)
- Scallopini (hybrid, AAS winner)
- Sunburst (hybrid, bright yellow, green spot at the blossom end)
- Butter Blossom (an open-pollinated variety selected for its large, firm male blossoms; fruit may be harvested like summer squash, but remove female blossoms for largest supply of male blossoms)
- Gourmet Globe (hybrid; globe-shaped; dark green, with light stripes; delicious)
- Sun Drops (hybrid, creamy yellow, unique oval shape, may be harvested as baby with blossoms attached).
When To Plant
Plant anytime after the danger of frost has passed, from early spring until midsummer. Some gardeners have two main plantings - one for early summer harvest and another for late summer and fall harvest.
Spacing & Depth
Sow two or three seeds 24 to 36 inches apart for single-plant production, or four or five seeds in hills 48 inches apart. Cover one inch deep. When the plants are 2 to 3 inches tall, thin to one vigorous plant or no more than two or three plants per hill.
Any well-drained garden soil produces excellent yields of summer squash. Certain mulches increase earliness and yields, because the roots are shallow.
Because summer squash develop very rapidly after pollination, they are often picked when they are too large and overmature. They should be harvested when small and tender for best quality. Most elongated varieties are picked when they are 2 inches or less in diameter and 6 to 8 inches long. Patty Pan types are harvested when they are 3 to 4 inches in diameter. Slightly larger fruit may be salvaged by hollowing out and using them for stuffing. These larger fruits may also be grated for baking in breads and other items. Do not allow summer squash to become large, hard and seedy because they sap strength from the plant that could better be used to produce more young fruit. Pick oversized squash with developed seeds and hard skin and throw them away. Go over the plants every 1 or 2 days. Squash grow rapidly; especially in hot weather and are usually ready to pick within 4 to 8 days after flowering.
Although summer squash has both male and female flowers, only the female flowers produce fruits. Because the fruits are harvested when still immature, they bruise and scratch easily. Handle with care and use immediately after picking. Be careful when picking summer squash, as the leafstalks and stems are prickly and can scratch and irritate unprotected hands and arms. Use a sharp knife or pruning shears to harvest and wear gloves if possible. Some gardeners also pick the open male and female blossoms before the fruits develop. Especially the female blossoms, with tiny fruit attached, are a delicacy when dipped in a batter and fried.
Cucumber beetles attack seedlings, vines and both immature and mature fruits. They can be controlled with a suggested insecticide applied weekly either as a spray or dust. Be alert for an infestation of cucumber beetles in early September because these beetles can damage the mature fruits.