Summer squash--including crookneck, straight neck, zucchini, white scallop, patty pan and cocozelle--is easy to grow in Minnesota gardens. Summer squash is a tender warm-season vegetable that may thrive even with little nurturing. But with just a little care, you can expect a large quantity of summer squash from a rather small number of plants. Sow summer squash seeds directly in the garden since transplanted seedlings tend not do so well.
Amend garden soil with compost or well-rotted manure before planting and till it in thoroughly.
Plant summer squash in late May in Minnesota, after the last danger of frost has passed and the soil temperature has warmed to 70 degrees F to a depth of at least 2 inches. Sow summer squash seeds half an inch deep and about 2 inches apart. Space the rows 2 to 3 feet apart.
Thin seedlings after they emerge so they are 8 to 12 inches apart. Pull weeds competing with the seedlings as needed.
In the absence of rain, water the summer squash weekly. Squash thrive with plenty of water. Soak the soil well once a week to provide the equivalent of an inch of rain per week. If your soil is sandy, though, water with smaller amounts more often.
Harvest summer squash when they reach the size you prefer. Elongated varieties of summer squash taste best when they are fewer than 2 inches in diameter, while patty pan types may be left to grow to 3 or 4 inches in diameter. Summer squash develop quite quickly after the plants have been pollinated, so check them frequently to avoid overgrown summer squash.