When to Plant Cauliflower in Honolulu, Hawaii (96821)

Location

Honolulu, Hawaii

ZIP Code

96821

USDA Zone

12b

Last Frost

Thursday, January 1, 2026

📅 Planting Calendar

Start Seeds Indoors Thursday, November 20, 2025

Transplant Outdoors Thursday, January 1, 2026

Pro Tip: Start Cauliflower seeds indoors 6 weeks before your last frost date, then transplant outdoors around Thursday, January 1, 2026.

🌿 Plant Details

Scientific Name Brassica oleracea var. botrytis

Days to Maturity 75 days

Mature Height 18-24"

Spread 24"

Type Head

Fruit Size Medium (6-8 inch head)

☀️ Growing Requirements

☀️

Sun

Full Sun (6 hours)

💧

Water

Regular (1-1.5 inches/week)

↔️

Spacing

18" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 4-10 days

Ready to Plant Cauliflower in Honolulu?

Get your seeds now so they're ready by Thursday, November 20, 2025.

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🤝 Good Companions

BeetCeleryBeanOnion

⚠️ Avoid Planting Near

StrawberryTomato

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Growing Cauliflower in Zone 12b

Cauliflower (Brassica oleracea var. botrytis) is a popular garden vegetable. In Honolulu, Hawaii, which is in USDA Hardiness Zone 12b, you should start seeds indoors around Thursday, November 20, 2025.

Your average last frost date is Thursday, January 1, 2026. Plan to transplant your Cauliflower seedlings outdoors around Thursday, January 1, 2026, about 0 weeks after your last frost date.