Squash is a warm-season crop that offers two distinct types for the home gardener. Summer squash, such as zucchini, has soft, thin, edible skin and is harvested when immature for immediate consumption. Winter squash, including butternut and acorn varieties, develop a hard, thick rind and are grown to full maturity, allowing them to be stored well into the colder months. Successful planting begins with preparing the garden site, sowing the seeds, and ensuring the young plants establish a robust root system. This step-by-step guide provides the practical details necessary for a successful squash harvest.
Preparing the Planting Site
Squash plants thrive in locations that receive a minimum of six hours of direct sunlight each day. Since squash is sensitive to cold, planting must be delayed until all danger of frost has passed. The soil temperature should register at least 60°F, with an optimal range between 65°F and 70°F for reliable seed germination.
The planting area requires deep preparation to ensure the large root systems have access to nutrients and proper drainage. Begin by loosening the soil deeply, such as by tilling, to a depth of at least a foot. Squash are heavy feeders, so incorporate several inches of aged compost or well-rotted manure into the loosened area to boost organic matter and fertility before planting.
A highly recommended technique is the creation of a “hill,” which is a small, raised mound of soil. The hill should be roughly 18 to 24 inches wide and 6 to 8 inches high. This elevated structure improves soil drainage and causes the soil to warm up faster in the spring, providing the ideal micro-environment for the seeds or transplants.
Sowing Seeds and Transplants
Squash can be started either by direct seeding into the garden or by using transplants started indoors several weeks earlier. For transplants, the seedlings should be hardened off to outdoor conditions before planting them out after the last frost date. Handle the root balls gently during this process, as squash roots are sensitive and do not take well to being disturbed.
When direct seeding, plant three to six seeds per hill to ensure successful germination. Push the seeds into the prepared soil to a depth of about one inch. For spacing between hills, measure 3 to 4 feet apart for bush-type summer squash varieties. Vining winter squash requires significantly more room, so their hills should be spaced a minimum of 6 to 8 feet apart.
If planting transplants, set two or three young plants into the top of the hill, spacing them about 4 to 6 inches apart. The concentration of the seeds or plants in a single spot makes the subsequent steps of watering and thinning more efficient.
Essential Post-Planting Establishment Care
Immediately after the seeds are sown or the transplants are set into the hills, provide a thorough, gentle watering to settle the soil around the seeds or roots. The initial watering ensures good soil-to-seed contact and hydrates the root ball, but care must be taken not to dislodge the seeds or wash away the top layer of soil. Following this, the soil should be kept consistently moist as the seeds germinate or the transplants establish new feeder roots.
Once the seedlings have emerged and developed their first set of true leaves, they must be thinned to prevent overcrowding and resource competition. For each hill, select the two or three strongest, most vigorous seedlings and remove the rest. To avoid damaging the delicate root systems of the remaining plants, use small scissors or snips to cut the unwanted seedlings off at the soil line, rather than pulling them out.
Young squash plants can be protected from early threats like cutworms and cucumber beetles by utilizing floating row covers. These covers create a physical barrier but must be removed once the plants begin to flower to allow pollinating insects access to the blooms. This protection, combined with consistent moisture, ensures the young plants can gain strength and size until they are fully established.