How to Grow Zucchini

Growing guide

Overview

Zucchini is a fast-growing summer squash that produces abundant fruit in just 45 to 60 days. Gardeners love it because a single plant can feed a family, but it needs full sun, consistent moisture, and regular picking to keep producing. It grows well in the ground or in a large container.

Soil & planting prep

Zucchini prefers loose, well-drained loamy or sandy soil rich in organic matter, with a pH between 6.0 and 7.0. Before planting, mix in 2 to 3 inches of compost or aged manure. Space plants 2 to 4 feet apart in rows 3 to 4 feet apart, and plant seeds 1 inch deep.

When to plant

Zucchini is not frost-tolerant and should be planted after the last frost date, when the soil has warmed to at least 60°F (15°C). You can start seeds indoors 3 weeks before the last frost, but direct sowing is easier and often catches up. In short-season areas, use black plastic mulch to warm the soil.

How to plant

1. Wait until all danger of frost has passed and the soil is at least 60°F (15°C).
2. Choose a spot in full sun with well-drained soil; amend with compost if needed.
3. Sow seeds 1 inch deep, 2 to 3 seeds per hill, with hills spaced 2 to 4 feet apart.
4. If starting indoors, sow 3 weeks before last frost in 3-inch pots and transplant after frost.
5. Water gently after planting and keep the soil evenly moist until seedlings emerge.

5 common mistakes to avoid

• Planting too early: zucchini seeds and seedlings rot in cold, wet soil, so wait until the soil is consistently above 60°F and all frost danger has passed.
• Overcrowding: zucchini plants become huge and need 2 to 4 feet of space each; planting them closer causes poor airflow and encourages powdery mildew.
• Inconsistent watering: drought stress leads to bitter fruit and blossom-end rot, so water deeply once or twice a week, aiming for 1 to 2 inches of water per week.
• Letting fruit get too large: oversized zucchini are seedy and tough, and the plant slows production; pick when fruits are 6 to 8 inches long.
• Watering from above: wet leaves invite fungal diseases like powdery mildew; water at the base of the plant instead.

Harvesting & storage

Harvest zucchini when the fruit is 6 to 8 inches long and the skin is glossy and easily pierced with a fingernail. Cut the stem with a knife or pruners, leaving a short stub. Store in the refrigerator for up to a week; for longer storage, blanch and freeze.

Companion planting

Good companions for zucchini include nasturtiums, which repel squash bugs, and corn, which provides shade. Avoid planting near potatoes, which compete for nutrients and can increase disease risk.

Growing in containers

Zucchini can be grown in containers, but it needs a large pot—at least 10 gallons per plant. Use a well-draining potting mix, water regularly, and place the container in full sun.

Pro tips

Direct sow after last frost. Give each plant 2-4 sq metres of space. Water at the base to prevent fungal disease. Pick frequently to keep the plant producing.