Summer Squash Growing Guide

Summer squash is a fast-growing, productive vegetable that thrives in warm weather. It’s a garden staple that can be grown in a variety of ways. Here’s how to successfully sow and grow summer squash:

When to Sow

Outdoors: Sow summer squash seeds after the last frost when soil temperatures have warmed to at least 70°F.
Indoors: Start seeds indoors 2-4 weeks before the last frost for an earlier start. Transplant once the weather is consistently warm. Learn more about the timing for sowing in the summer squash guide.

Outdoor Sowing

Choose a sunny location with well-drained, fertile soil.
Sow seeds 1 inch deep, spacing plants 2-3 feet apart, depending on the variety. Rows should be spaced 3-4 feet apart to give the plants room to spread.
Water gently after sowing and keep soil consistently moist until germination (7-10 days).

Indoor Sowing

Sow seeds 1 inch deep in seed trays or small pots filled with a well-draining soil mix.
Keep the soil moist and warm (70-85°F).
Transplant outdoors once seedlings have two sets of true leaves and the frost danger has passed. Handle carefully to avoid disturbing the roots.

Care & Maintenance

Light: Summer squash requires full sun.
Watering: Water regularly, especially during flowering and fruiting stages. Keep the soil moist but avoid waterlogging.
Mulching: Apply mulch around the plants to retain moisture and suppress weeds.
Fertilizing: Fertilize when the plants begin to flower and again as they start producing fruit. For tips on maximizing space, check out growing squash vertically.

Pests & Diseases

Common pests include squash bugs, cucumber beetles, and vine borers. Use row covers to protect young plants and inspect them regularly for pests.
Summer squash is prone to powdery mildew and other fungal diseases. Ensure good air circulation, avoid overhead watering, and plant in well-drained soil. For more advice, see summer squash varieties and care.

Harvesting

Harvest summer squash when the fruits are young and tender, usually when they are 6-8 inches long for zucchini or 3-4 inches in diameter for round varieties.
Use a sharp knife or scissors to cut the fruit, leaving a short stem attached. Regular harvesting encourages more fruit production and prevents the squash from becoming oversized and tough. For more on variety differences, check out zucchini vs summer squash.

Garden Use

Summer squash is ideal for garden beds, raised beds, and companion planting with crops like corn, beans, and radishes. Their large leaves provide soil shade, which helps retain moisture and reduce weed growth.

Availability of Cube of Butter Summer Squash Seeds
Due to supply challenges, we are unable to offer Cube of Butter summer squash seeds for the 2025 season. Our previous grower could not provide a sufficient quantity. While we are actively working to restock this variety, there is no confirmed date for its return. Rest assured, we are doing our best to bring it back as soon as possible.

Summer Squash Growing GuideUpdated 9 days ago