Sow about 24 inches apart in a row at a depth of about an inch the third or fourth week of May. Or, start squash three weeks earlier under protection for quickest yields. If you harvest plants regularly, when the fruit are at a fairly young stage, they will continue to produce additional squash for weeks, even months. However, squash plants often begin to look ragged, succumbing to mildews & other diseases that slow down production. It’s best to make two additional sowings at one-month intervals to have summer squash available all season. Zucchini Heirloom Squash Cocozelle Seed 25