The Best Time to Sow Squash Seeds

Winter squash need plenty of room to grow.

Squash fall into two categories: winter squash and summer squash. Winter squash, such as pumpkins and acorn squash, grow on sprawling vines, have hard rinds and store well. Summer squash, such as zucchini and yellow squash, are more compact, grow quickly and should be used within a few days of picking.

Time Frame

Squash seeds are very sensitive to cold temperatures. Wait until at least two weeks after the last expected frost to plant them. Black mulch applied two or three weeks prior to planting helps warm up the soil and hastens germination.

Soil Temperature

Plant squash when the temperature of the soil is at least 65 degrees Fahrenheit but preferably 70 degrees, the Cornell University department of horticulture advises. Squash seeds germinate best when temperatures are above 95 degrees Fahrenheit.

Considerations

Winter squash require a longer growing period than summer squash. Plant them by mid-June---or choose fast-maturing varieties if sowing later---to give them time to ripen before autumn frosts.

References

• Cornell University: Growing Guide: Summer Squash
• Cornell University: Growing Guide: Winter Squash

Resources

• University of Illinois Extension: Summer Squash