Planting Guide and Seed Saving Notes for Squash

Squash (Cucurbita pepo)

Summer Squash

By mid-summer, most gardeners are blessed with the problem of too much summer squash! These bushy plants are found in every garden, often volunteering to guard the compost pile with large spreading leaves. Summer squash are the same species as many winter squash but they are eaten at the immature stage, when the skin is still very delicate & tender. A farming trick to keep up a regular harvest and reduce disease pressure is to plant successions 3-4 weeks apart in different locations and pull out older plants mercilessly after 4-5 weeks of harvest. Otherwise they can become hosts to mildew, squash bugs, and vine borers.

Winter Squash & Pumpkins

Contrary to the name, winter squash is actually grown in the summer, started the same time as summer squash, but it takes much longer to mature. When it is ripe the fruits will have a hard outer shell and store all winter. Plants are known for their unwieldy vines that will stealthy claim ownership to any garden space they have access to so give them their space. All squash are symbiotic members of the “Three Sisters” (along with Corn and Beans) in Native American agriculture. Corn provides a pole for vining beans which in turn provide nitrogen for the heavy-feeding corn. With their numerous large leaves, squash shades out the weeds and helps retain moisture in the soil for all. Nutrients: vitamins A, C, and B, potassium, manganese.

Nutrients: vitamins A, B6, C, E, K, folate, riboflavin and manganese. 

How to Grow Squash from Seed

Bed Preparation

Summer squash is a frost sensitive annual that prefers full sun and fertile soil that is consistently moist, but well-drained.

Winter squash is a frost sensitive annual that prefers full sun and fertile soil that is consistently moist, but well-drained. Choose an area with plenty of space for the sprawling vines.

Planting

Direct-seed outdoors once the danger of frost has passed and soil temperatures have warmed to at least 65˚ F for 2 weeks. Plant seeds in hills (warm quickly and drain well) or rows. Space hills 3-4' apart and plant 4-5 seeds ½-1” deep. Seeds will sprout in 5-10 days. When seedlings are 3-4" tall, thin to 2-3 plants per hill. In rows, plant seeds ½" deep and 6" apart with rows 4-5' apart. Mulch around plants to conserve moisture and reduce weeds. To extend your harvest, succession plant every 4 weeks until frost. Seeds can also be started indoors 3-4 weeks before the last frost date and transplanted outdoors.

Harvest

Summer squash should be harvested frequently to encourage plants to continue producing. For the best taste and texture, harvest squash before they are too large; 6-10" for yellow and zucchini squash; 8-18" for trombocino squash.

Winter squash is typically ready for harvest in 90-115 days. Harvest winter squash in fall before frost, when the rind is a consistent deep color and very firm. If in doubt, open one before harvesting others. For some varieties, flavor will improve with storage.

How to Save Squash Seeds

Squashes are an insect pollinated monoecious (male and female flowers on the same plant) annual that are very high producers of nectar, making them very attractive to pollinators, especially honeybees. There are four species of squash commonly grown in North America: C. maxima, C. argyrosperma, C. Moschata, and C. pepo. Because the four species do not cross with each other, this allows you to grow four different species in the same garden. Squash must be fully mature before harvested for seed production. This means that summer squashes must be left on the vine until the outer shell hardens. Allow to cure for an additional 3-4 weeks after harvest to encourage further seed ripening. Cut open fruits and scrape out seeds and pulp into a jar or bucket, filling with an equal amount of water. Ferment seeds for 2 to 4 days, pour off the floaters and wash the rest of the seeds clean from the wet chaff. Spread on a screen or several sheets of newspaper to dry thoroughly before storage. This could take several weeks.