Squash Plant Wilts and Dies

Season

• Summer and winter squash cultivars require warm, temperate conditions. Squash seedlings wilt and die in early spring frosts and soil temperatures under 60 degrees Fahrenheit. The University of Minnesota Extension recommends setting squash seeds or seedlings out when soil temperatures reach 70 degrees. Squash plants also wilt, yellow and die back in fall when temperatures drop below 60 degrees and frost approaches.

Site and Sun

• Squash plants need full sunshine all day, with good air circulation and site drainage. Leaves yellow and wilt in shade while roots rot and die in standing water. Plant squash seedlings at appropriate spacing to allow for good air and sun exposure. Summer squash plants require 24 to 36 inches in the row while larger winter squash plants require up to 5 to 6 feet for long, vining growth. If shaded squash plants begin to fail, move them to a sunnier location.

Soil and Nutrition

• Squash grows in a range of soils but does best with a rich, quick-draining and slightly acidic foundation. The plants cannot support foliage or fruit growth without adequate nutrition. Amend soil with organic compost or well-rotted manure at planting and in mid-season to maintain soil quality. Give squash plants balanced fertilizer at planting and 46-0-0 or 27-3-3 granular fertilizer at mid-season.

Water and Mulch

• All plants wilt and die if they don't get enough moisture. This is particularly true of summertime vegetable plants, which require generous moisture content and must grow through the harshest, driest season of the year. Water squash plants with at least 2 inches of water every week and especially during the dry, late-summer months. The University of Illinois Extension notes that plastic or organic mulch helps maintain better soil moisture for squash, and enhances growth and production.