Squash (Summer): Sow and Grow GuideUpdated 14 days ago

Summer squash is a fast-growing, productive vegetable that thrives in warm weather and is a staple in many gardens. Here's a concise guide to successfully sowing and growing summer squash.

When to Sow

Sow summer squash seeds outdoors after the last frost when the soil has warmed to at least 70°F. For an earlier start, seeds can be sown indoors 2-4 weeks before the last frost and transplanted once the weather is consistently warm.

Outdoor Sowing

Choose a sunny location with well-drained, fertile soil. Sow seeds 1 inch deep and 2-3 feet apart, depending on the variety. Space rows 3-4 feet apart to allow plenty of room for the plants to spread. Water gently after sowing and keep the soil consistently moist until germination, which typically takes 7-10 days.

Indoor Sowing

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

Care and Maintenance

Summer squash requires full sun and regular watering, especially during flowering and fruiting. Keep the soil consistently moist but avoid waterlogging. Mulch around the plants to retain moisture and suppress weeds. Fertilize with a balanced fertilizer when the plants begin to flower, and again as they start to produce fruit.

Pests and Diseases

Common pests include squash bugs, cucumber beetles, and vine borers. Protect young plants with row covers and inspect regularly for pests. Squash is also susceptible to powdery mildew and other fungal diseases, so ensure good air circulation, avoid overhead watering, and plant in well-drained soil.

Harvesting

Harvest summer squash when the fruits are young and tender, typically 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 from the plant, leaving a short stem attached. Regular harvesting encourages more fruit production and prevents the squash from becoming oversized and tough.

Garden Use

Summer squash plants are excellent for garden beds and raised beds. They are also good companions for corn, beans, and radishes, which can help deter pests and improve garden health. Their large leaves can also provide shade for the soil, helping to retain moisture and reduce weed growth.

For further details, visit the full guide on the Botanical Interests Blog.