How to Grow Zucchini and Other Summer Squash
Summer squash is one of the most bountiful vegetables you can grow in your backyard. A 5-foot row alone can yield 10 pounds! This crop grows very quickly in warm weather, so be sure to check on your garden daily. With the right care and growth tips, this ever-popular vegetable will be an abundant favorite in your garden.
Varieties of Squash
Of the summer soft-skinned varieties, the most commonly planted are: 'Early Prolific Straightneck' (yellow), 'Zucchini Elite', 'Fordhook Zucchini', 'Cocozelle Bush' (green), 'White Bush Patty Pan', and 'Scallopini Hybrid'. Fall and winter hard-skinned varieties include: 'Royal Acorn', 'Bush Buttercup', 'Bush Acorn', 'Table King', and 'Bush Gold Nugget'. 'Spaghetti' is a novelty variety that produces tasty pulp that looks like spaghetti when cooked and removed from the squash shell. When choosing a variety, consider space needed, days to maturity, yield, and disease resistance.
How to Plant Squash
If space is limited, choose bush varieties only, or grow squash vertically on a trellis or wire. Prepare the bed with compost, peat, or well-rotted manure, then add commercial fertilizer. Plant squash in hills or clusters when the soil warms, spacing six seeds about 2 inches apart. A common misconception is that the soil must be mounded, but this is a matter of choice. The advantage of raised hills is that, like raised beds, they drain well and dry out quickly. Space the hills about 6 feet apart. In cool, wet areas, mulch with clear or black plastic.
When the seedlings emerge, thin them to three healthy plants per hill. Apply a thick organic mulch around the plants if you are not using black or clear plastic. Water plants regularly. Use drip irrigation if possible; otherwise, flood the bases of plants with water to avoid mildew. Side-dress with fertilizer every 10 days for healthy growth. If vines get out of hand, snip the growing tips to encourage lateral branching.
Watch for borers, cucumber beetles, and squash bugs. Kill them with an insect control product approved for use on vegetables. Destroying cucumber beetles will help prevent bacterial wilt, one of the worst diseases in the squash patch.
Summer squash develops quickly, so check fruits daily as they begin to form. Though certainly edible when large, summer squash tastes better and is tenderer when harvested while still small. Cut off zucchini and straightnecks when they are only a few inches long, and pattypans when no larger than a quarter. Harvest all fruits whether you can eat them or not. Give away or compost what you can't use. If you allow fruits to ripen on the plants, they give off a hormone that causes the plants to shrivel and die. Constant picking also stimulates increased production. Flowers of summer squash are edible. Choose the male flowers (those without small squashes developing at their bases; plants produce male flowers first).
Allow winter squash, on the other hand, to mature completely before picking it. Wait until the stems begin to dry and wither. Cut the fruits from the vines, leaving an inch or two attached to each squash. Do not carry squash by these stems. Place the squash (except acorn squash) in a sunny, dry location for several days, then move it inside to a warm, dry area for several weeks. This curing process allows the shells of the fruits to harden. Store them in a dark room at temperatures between 55 and 60 degrees. Store acorn squash, which can be eaten young or mature, according to taste, in cool temperatures from the start.
To develop a zucchini that has specific desired qualities, we suggest pollinating selected plants by hand and excluding pollinating insects, then harvesting the resulting zucchini. Start by removing the petals from a male zucchini flower. Hold the fully exposed stamen like a paintbrush and coat a female flower on the selected zucchini plant with pollen. Staple a small pollination bag shut over the flower to keep out pollinators.