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Growing Squash in the Home Garden
This article was published originally on 4/1/2003
Summer and winter squash are some of the most popular vegetables in the home garden. Summer squash can be eaten raw in salads, stir-fried, steamed, or cooked in various dishes. Winter squash can be baked, steamed, or boiled.
Summer squashes are large, bushy plants. The fruit of summer squash are harvested when they are immature and have soft skins. Fruit can be stored for 1 to 2 weeks. There are several types of summer squash. These include zucchini (cylindrical, club-shaped fruit), crookneck (long, tapered fruit with curved necks), straightneck (bottle-shaped fruit with straight necks), and scallop (flattened, roundish fruit with scalloped edges).
Most winter squashes are large, vining plants. (Several semi-bush varieties are available to individuals with small gardens.) Fruit are harvested when they are mature and have hard rinds. Winter squash fruit can be stored in a cool, dry location for 1 to 6 months. Various sizes, shapes, and colors of winter squash are available. These include acorn, buttercup, butternut, and hubbard.
Summer and winter squash perform best in fertile, well-drained soils containing high levels of organic matter. They also require full sun. Organic matter levels can be increased by incorporating well-rotted manure or compost into the soil. If a soil test has not been conducted, apply and incorporate 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet prior to planting.
Summer and winter squash are commonly planted in hills. Sow 4 to 5 seeds per hill at a depth of 1 inch in mid-May in central Iowa. Thin to 2 to 3 vigorous, well-spaced plants per hill when seedlings have 1 or 2 true leaves. The last practical planting date for summer squash is July 20. Winter squash must be planted by June 10.
For an early crop, start plants indoors 3 to 4 weeks prior to the anticipated outdoor planting date. Since squash seedlings don't tolerate root disturbances during transplanting, start seeds in peat pots, peat pellets (Jiffy 7's), or other plantable containers. Sow 3 to 4 seeds per container. Later, remove all but 2 seedlings. Harden the plants outdoors for a few days in a protected location prior to planting to lessen transplant stress.
Hills and rows of summer squash should be 3 to 4 feet apart. Hills of winter squash should be spaced 4 to 5 feet apart with 5 to 7 feet between rows.
Control weeds with frequent, shallow cultivation and hand pulling. Water plants once a week during dry weather.
Squash bugs and squash vine borers can be serious pests. Squash bugs have piercing-sucking mouthparts. Heavy feeding causes entire leaves to wilt, turn brown, and die. Several methods can be used to control squash bugs in the garden. Adults and brick red egg masses on the undersides of leaves can be removed by hand. Adults can also be trapped under boards or shingles placed under the plants. Turn the objects over daily and collect and destroy the hiding squash bugs. Small, immature squash bugs (nymphs) can be controlled with insecticides, such as carbaryl (Sevin). In fall, remove and destroy plant debris to deprive squash bugs of overwintering sites.
Squash vine borer larvae bore into squash stems near ground level. Larvae feeding within the vines eventually causes the plants to wilt and die. Squash vine borers can be controlled with applications of insecticides (rotenone, permethrin, or malathion) at regular intervals beginning in mid-June. Apply the insecticide to the base of the vines. After the final harvest, remove and destroy the plant debris. Rototilling in fall or spring may destroy overwintering pupae in the soil.
Harvest long-fruited summer squash varieties when they are about 2 inches in diameter and 6 to 12 inches long. Scalloped types are best when 3 to 5 inches in diameter. Fruit should have soft skins (rinds) that are easy to puncture with a fingernail. Seeds should be soft and edible.
Mature winter squash have very hard skins that can't be punctured with the thumbnail. Additionally, mature winter squash have dull-looking surfaces. When harvesting fruit, leave a 1-inch stem on winter squash. Store the fruit in a cool, dry, well-ventilated location.
Year of Publication:
IC-489(6) -- April 1, 2003