When to Plant Broccoli: Timing by Zone and Season

Broccoli thrives in cool weather, and timing your planting right is the key to a healthy, productive harvest. Knowing when to plant depends on both your USDA Hardiness Zone and whether you’re aiming for a spring or fall crop. Plant too early and frost can damage seedlings; plant too late and heat can cause plants to bolt before producing heads.

Table of Contents

Spring Planting by Zone

In Zones 3–5, start broccoli seeds indoors 6–8 weeks before your last expected frost, then transplant outdoors 2–3 weeks before the last frost date. Zones 6–7 can start seeds indoors about 4–6 weeks before the last frost and transplant 1–2 weeks before. In Zones 8–10, where winters are mild, broccoli can be planted in late winter for a spring harvest — direct sow or transplant seedlings as soon as daytime temperatures are consistently between 55°F and 75°F.

Fall Planting by Zone

For Zones 3–5, start seeds indoors 12–14 weeks before your first expected fall frost, then transplant 6–8 weeks before frost. Zones 6–7 can start seeds indoors 10–12 weeks before frost and transplant 5–7 weeks ahead. In Zones 8–10, broccoli is often planted in late summer to early fall for a winter harvest; aim to transplant once daytime highs drop below 85°F.

Seasonal Considerations

Broccoli grows best in temperatures between 60°F and 70°F. In spring, plant early enough so heads mature before daytime temperatures regularly exceed 75°F. In fall, time planting so heads form during the cooler weather of early to mid-autumn. Avoid planting during peak summer heat to prevent bolting and poor head development.

Summary

Broccoli loves cool weather. Planting at the right time ensures big, flavorful heads before heat or frost damage sets in.

Spring Planting:

Zones 3–5: Start indoors 6–8 weeks before last frost; transplant 2–3 weeks before last frost.
Zones 6–7: Start indoors 4–6 weeks before last frost; transplant 1–2 weeks before.
Zones 8–10: Plant late winter; grow in 55–75°F weather.

Fall Planting:

Zones 3–5: Start indoors 12–14 weeks before first frost; transplant 6–8 weeks before.
Zones 6–7: Start indoors 10–12 weeks before first frost; transplant 5–7 weeks before.
Zones 8–10: Plant late summer; transplant when highs are below 85°F.

Final Tips

Always check your seed packet for variety-specific days to maturity and adjust your planting schedule accordingly. Using row covers in early spring can protect seedlings from frost and pests, while mulching in fall helps retain soil warmth. With careful timing and zone-based planning, you can enjoy crisp, flavorful broccoli almost year-round.