Cauliflower Planting Calendar: Month-by-Month Guide

Growing cauliflower successfully depends on timing. After more than three decades of raising brassicas in my California garden, I’ve learned that knowing exactly when to sow, transplant, and harvest makes the difference between big, tender heads and disappointing button-sized florets.

This month-by-month cauliflower planting calendar will help you plan your crop whether you’re gardening in spring or fall, in cool northern regions or warmer southern climates.

Table of Contents

General Timing Rules

Cool-season crop: Cauliflower thrives in temperatures between 60°F and 70°F.
Spring crops: Start seeds 4–6 weeks before the last expected frost, transplant outdoors 2–4 weeks before frost ends.
Fall crops: Start seeds 12–14 weeks before first fall frost; fall plantings often yield better heads than spring.

My experience: In Sonoma Valley, I start seeds indoors in mid-January for spring crops and again in late July for fall harvest.

Month-by-Month Cauliflower Planting Calendar

January

Mild climates: Start seeds indoors for spring crops.
Cold climates: Prepare seed-starting supplies.

February

Start seeds indoors in most regions.
Harden off seedlings toward month’s end in mild zones.

March

Transplant seedlings outdoors in temperate regions 2–4 weeks before the last frost.
Direct sow in mild climates with consistent soil temps above 50°F.

April

Main transplanting month in cool and temperate zones.
Protect seedlings from late frosts with cloches or row covers.

May

Last chance for spring plantings in cooler climates.
In warm regions, avoid planting until mid-summer for a fall crop.

June

Too warm for new spring plantings. Focus on watering and care of existing crops.
Start fall crop seedlings indoors in cooler northern zones.

July

Sow seeds indoors or directly outdoors for fall harvest in most regions.
Provide shade cloth if heat is excessive.

August

Transplant fall crop seedlings to the garden.
Keep soil cool and moist for steady growth.

September

Continue transplanting for fall crops in warm zones.
Begin harvesting early-maturing varieties.

October

Harvest fall cauliflower in most regions.
Protect plants with row covers if frost threatens before heads mature.

November

Mild regions: Continue harvesting.
Cold regions: Clear beds and prepare soil with compost for next year.

December

In frost-free climates, harvest late fall crops.
Plan seed orders for next season.

Tips for Using the Calendar

Adjust for your region: Always use your local frost dates as your guide.
Succession sowing: Stagger seed starts every 2 weeks to extend the harvest window.
Fall focus: If spring crops have failed, shift to fall planting—it’s often easier and more rewarding.

Personal insight: My best cauliflower heads always come from fall plantings. The steady cool weather helps heads form fully without stress.

Final Thoughts

Planting cauliflower isn’t just about picking a date—it’s about aligning with your climate, frost dates, and seasonal weather patterns. Use this calendar as a guide, adjust it to your region, and you’ll have a reliable roadmap for growing big, tender cauliflower heads every year.