Growing Summer Squash

Summer squash are one of the most productive plants in the garden. They are a great choice for West Virginia gardeners as they are easy to grow and quickly produce many fruits that are dense in nutrients, such as vitamin C. Members of the Cucurbita genus, summer squash are warm-season annuals. In contrast to winter squash, they should be harvested when tender before the rind hardens. Fruits are eaten immature, typically about four to seven days after the plant blooms. Fruits come in straight, crookneck, and scalloped or patty pan varieties and vary in color from green to yellow to white.

Production

Most summer squash are a bush-type plant, instead of vining, and do not require an extensive amount of space. Squash prefer full sun and can be seeded directly into the garden once danger of frost has passed. Mounds of three to four seeds should be planted approximately 3 to 4 feet apart. Plants placed too close together will not allow for proper airflow and can increase the chance of disease. Seedlings can be thinned to one or two plants once they reach 3 to 4 inches in height. Summer squash also can be grown in a large container and do well in raised beds. 

Seeds will sprout quickly, usually in about a week. If using transplants, ensure they have a well-developed root system and are healthy. Purchasing transplants will allow you to buy a few plants of several varieties, while purchasing seeds allows for more plants at a lower cost. Squash can be planted on plastic mulch if preferred, but black plastic should be avoided in hotter climates. Most squash should be planted from late May through mid-June in West Virginia as they are not frost tolerant. 

Soils

Squash varieties require warm soil beds, so plant after the last frost date for your area in a location that gets full sun. Work the soil, adding compost and fertilizer based on soil test recommendations, as squash prefer loose, well-drained soil. Free soil testing is available to West Virginia residents from the WVU Soil Testing Lab. (  https://soiltesting.wvu.edu/) If no soil test has been completed, add 2 tablespoons of 10-10-10 fertilizer per mound at planting. Additional fertilizer can be side dressed once plants flower and begin to make fruit. 

Watering

Water each plant or seed mound when planting and water daily for the first few weeks to ensure establishment; once established, water as needed based on soil moisture. Avoid watering the top of the plant and leaves, as this can increase the chance of disease. Soaker hoses or drip irrigation distribute water evenly and efficiently. Squash harvested when young and tender will contain up to 95% water.  Plants must have enough water to develop and set fruits, but take care to not overwater. 

Harvest and Storage

Once summer squash plants begin setting fruit, they should be picked daily. Fruit will develop rapidly, and they should be picked when tender for the best quality, typically when elongated varieties are 6 to 8 inches long. Carefully snip from the vine with scissors or a sharp knife not to damage the vine. Larger fruits will start to harden and hollow out, getting an abundance of seeds. Once picked, squash should be refrigerated and used within a few days. It is important to handle fruit carefully as they bruise easily. 

Varieties

Nutrition

Yellow summer squash is an excellent source of vitamin A (beta carotene), and all varieties are good sources of vitamin C. Squash also contains a moderate amount of potassium and folate, a B vitamin that can help prevent birth defects. Deficiency in folate also can lead to some forms of anemia. According to the USDA nutrition facts, one medium raw squash (approximately 1 cup cubed) contains 31 calories, 2 grams of protein and 32% of the daily vitamin C requirement. Beta carotene content and actual calorie content will vary depending on variety.  

Cooking

Winter squash can be fried, baked, roasted, steamed or microwaved.  Their light flavor can be accented by numerous spices or emphasized by a simple combination of olive oil or butter with salt and pepper. Pureed zucchini can be added to breads and brownies to keep them moist. Grilled squash is a favorite summer recipe, and fried squash is a traditional southern favorite. Squash blossoms are a delicacy in some restaurants.

Preserving

Canning squash is not generally recommended as pressure canning can make it soft and mushy. Squash are a low acid vegetable, so a water bath canner is not sufficient to reduce the risk of the bacteria that causes botulism. Freezing is the preferred method to preserve summer squash. Choose tender summer squash with rinds that have not begun to harden. Wash the outer surface, removing any dirt or debris. Cut into slices 1/4-inch thick or cubes up to 1 inch. Blanch by placing squash in boiling water for three minutes, then transferring immediately to ice cold water. Drain dry and pack into freezer bags, freezer containers or vacuum seal. Blanching stops enzyme action in vegetables, which preserves the flavor, color and texture when freezing. Freeze quickly and keep frozen until use, which should be within 12 months for food safety and best quality.

Pollination

Squash plants produce both male and female flowers on each plant, and pollen must be carried from male flowers to females, usually by insects, for pollination and fruit set to occur. Female flowers have a shorter stemmed flower with a swelling behind it, where the ovary is present. Squash may produce male flowers a week or so before the female flowers, and they may start to fall off, which is normal. However, if female flowers aren’t pollinated, they also will fall off. Pollination and fruit set may not occur if the weather has been exceptionally rainy or cold, there’s been inappropriate use of pesticides or there are not enough pollinators in the area. Gardeners can pollinate female flowers by collecting pollen from the male flowers with a cotton swab and placing it on the stigma in the female flower. Squash will cross-pollinate with other varieties, including some winter squash and pumpkins, so it is best not to save seed, as next year’s plants could yield surprising results. 

Insects, Diseases and Other Issues

References

USDA Squash nutrition label:  https://snaped.fns.usda.gov/seasonal-produce-guide/summer-squash

Vegetable Varieties Recommended for West Virginia:  https://extension.wvu.edu/files/d/efe1bf03-9296-449c-8027-fff3e359d769/vegetable-varieties-recommended-for-west-virginiazx.pdf

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