When and How to Plant Cauliflower for Best Results

Cauliflower is one of the most rewarding but finicky vegetables to grow in the home garden. Over the past 30 years of growing cool-season crops in raised beds and containers, I’ve learned that cauliflower rewards careful planning—and punishes neglect. Plant it right at the start, and you’ll enjoy big, tender, delicious heads. Get the timing or conditions wrong, and the plants may button (form tiny heads), bolt, or refuse to form heads at all.

In this post, I’ll share when and how to plant cauliflower for the best results based on both my gardening experience and proven horticultural practices.

Table of Contents

When to Plant Cauliflower

Cauliflower is a cool-season crop that grows best when daytime temperatures are between 60°F and 70°F. Hot weather causes stress and bolting, while cold weather can stunt growth.

Spring planting: Start seeds indoors 4 to 6 weeks before your last expected frost. Transplant seedlings outdoors 2 to 4 weeks before the last frost date, when soil temperatures reach at least 50°F.
Fall planting: For a fall harvest, sow seeds 12 to 14 weeks before your first expected frost. Fall crops often perform better than spring crops because they mature in cooler, steadier weather.

My experience: In Sonoma Valley, I start cauliflower indoors in mid-January for spring crops and direct sow in late July for fall. The fall harvest is almost always more dependable because the plants mature as the days cool.

How to Plant Cauliflower

Step 1: Start Seeds Indoors (Recommended for Spring)

Sow seeds in seed trays filled with a fine seed-starting mix.
Plant seeds about ¼ inch deep and keep them evenly moist.
Maintain a temperature of 65°F to 70°F for strong germination.
Thin seedlings so the strongest plants remain.

Step 2: Harden Off Seedlings

Before transplanting, gradually acclimate seedlings to outdoor conditions over 7 to 10 days. I move my trays outside for a few hours each day, increasing exposure until the seedlings can handle full sun and fluctuating temperatures.

Step 3: Transplant to the Garden

Space plants 18 to 24 inches apart in rows 24 to 36 inches apart.
Set transplants slightly deeper than they were in containers for stronger anchoring.
Water well after planting to reduce shock.

Step 4: Direct Sowing (Best for Fall Crops)

Sow seeds directly into prepared soil about ½ inch deep.
Thin seedlings to the proper spacing once they develop 2–3 true leaves.

Soil Preparation

Cauliflower thrives in fertile, well-drained soil with a pH of 6.0 to 7.0. Mix compost or well-rotted manure into the bed before planting. Avoid nitrogen-heavy fertilizers at planting time—too much nitrogen encourages leafy growth at the expense of heads.

In my own garden, I add a layer of homemade compost to the bed, rake it smooth, and plant directly into the enriched soil.

Tips for Planting Success

Consistent moisture: Cauliflower is sensitive to drought. Keep soil evenly moist, not soggy.
Mulch: Apply organic mulch around plants to conserve moisture and regulate soil temperature.
Cool roots, sunny tops: Cauliflower prefers full sun but appreciates cool, shaded soil around its roots.
Crop rotation: Avoid planting cauliflower (or other brassicas like broccoli or cabbage) in the same spot year after year to reduce disease buildup.

Common Planting Mistakes to Avoid

Planting too late in spring: Warm weather causes bolting before heads form.
Crowding plants: Too little space leads to smaller heads.
Neglecting hardening off: Transplants may wilt or stall if moved outdoors too quickly.

Final Thoughts

Cauliflower can be tricky, but the effort pays off. The key is planting at the right time and giving plants a good start with rich soil, steady moisture, and proper spacing.

In my garden, fall plantings consistently outperform spring ones—so if you’ve struggled before, try timing your crop for late summer sowing and cool-weather harvest. With experience and careful planning, you’ll soon enjoy fresh, tender cauliflower from your own backyard.

Cauliflower Learning Hub

Start here: The Ultimate Cauliflower Growing Guide: From Seed to Harvest

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