Melons, squash, and cucumbers grow best where the summer is hot, dry, and almost always sunny. The best flavored of these gourd family (Cucurbitaceae) crops will come from the hottest growing regions. Both cloudy and rainy weather will slow and all but stop Cucurbit growth.
Melons, squash, and cucumbers grow best when both the soil and air temperature is at least 70°F; sow seed directly in the ground at least 2 weeks after the last frost. Expect germination in 3 to 10 days, depending on the soil temperature. (The higher the temperature the faster the seed will sprout.)
If your growing region cannot sustain soil and air temperatures of 70°F or greater for 75 to 100 days then keep in mind that squash are the hardiest members of the gourd family—meaning they will grow in cooler conditions if need be. Cucumbers are somewhat less hardy than squash; cantaloupes are less hardy yet; and watermelons are the least hardy members of the gourd family—meaning they demand the most heat.
Give melons, cucumbers, and squashes a long growing season; a long, hot growing season will increase flavor and yield.
Plant seeds in the garden as soon as the soil is warm and dry to give these crops the greatest number of hot days. Get a head start on the season by starting plants from seed indoors, 2 to 3 weeks before the last frost, then transplant seedlings to the garden no sooner than 2 weeks after the last frost.
• Watermelons require 70 to 85 days from transplanting—which means about 110 days overall from seeding to ripe fruit. Watermelons that require the shortest season include Garden Baby (75 days) and Sugar Baby (80 days); these are among the smallest watermelons weighing in the 7 to 10 pound range at maturity.
• Cantaloupe, muskmelons, honeydews, and casaba melons require 70 to 140 days to reach maturity depending upon variety. Nighttime air temperatures should not dip below 65°F for best growth and flavor.
• Cucumbers require 55 to 65 days to reach maturity depending upon variety. They can be sown or set out in soil as cool as 60°F—but it is best to warm the soil for 5 days by covering it with clear plastic sheeting before getting started.
• Winter squashes require 80 to 100 days to maturity depending upon variety. Both winter and summer squashes can be set out in soil as cool as 60°F, but in cool soil it would be best to cover the planting bed with black plastic to speed up plant growth.
• Summer squashes–including pattypan, scalloped, yellow, and zucchini–will survive where nights dip below 65°F, but if temperatures go any lower protect your crop with a floating row cover. These crops require 50 to 65 days to reach maturity.
Watering for Optimal Growth
Gourd or melon family crops have deep taproots that seek out soil moisture. Direct watering will cool off and slow the growth of these heat-loving crops, so if irrigation is necessary where you live, water at the edge of growing hills or beds, not directly on or at the base of plants so as not to slow growth. Where irrigation is required and the weather is hot, give melon family crops 1 to 2 inches of water each week.
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