Yellow squash (Cucurbita spp.) is a fast-growing member of the gourd family that can be enjoyed in many ways including sauteed, fried, grilled, steamed or boiled. Unlike winter squash, this summer squash variety doesn't store well and is harvested before it matures, within about two months after planting it. Yellow squash doesn't tolerate frost, which makes properly starting this warm-season vegetable essential to your success.
Whether you direct-sow yellow squash seeds or use transplants in spring, the soil must be least 60 degrees Fahrenheit and all frost danger should have passed. In cooler climates or areas with erratic weather, start the seeds indoors about three to four weeks before the last spring frost date. Spread black plastic mulch over the soil about 10 days before transplanting to hasten the soil-warming process. Then, transplant through slits cut into the plastic, and use floating row covers to protect young plants from unexpected cold spells.
2. Soil Requirements
Early in the planning process, perform a soil test to determine the pH of the soil in your garden. Yellow squash thrives in soil with a pH range between 5.5 and 6.8. Depending on your test results, work sulfur into the top 7 inches of soil to lower the pH, or incorporate limestone to raise it. Then, before transplanting or direct-sowing, loosen the soil to a depth of 12 inches with a tiller or garden fork, and work in a 2-inch layer of compost to improve nutrients and drainage.
3. Transplanting or Sowing
If you're transplanting yellow squash seedlings in the garden, space them about 18 to 36 inches apart, and plant them at the same depth that they were growing in their previous container. To direct-sow, plant the seeds 1 inch deep at a rate of two to four seeds per foot. Then, after the first true leaves develop, thin the seedlings to the strongest one so they end up spaced 18 to 24 inches apart.
To thrive, provide yellow squash with about 1 inch of water per week during the growing season. Keep the soil moist -- not wet -- the entire time. Adjust your watering frequency during dry, hot spells or after rainfall. When the plants have five leaves, spread a 2-inch layer of organic mulch, such as straw or chopped leaves, on the soil around them to combat weeds and promote soil-moisture retention. The plants are harvest-ready after 50 to 65 days, when the fruit is 6 to 8 inches long.