Last Updated on September 17, 2026
How Many Cauliflower Plants per Square Foot?
1 cauliflower plant per square foot, set in the center of the square, 12 inches apart. That is what my square foot gardening chart gives cauliflower, and the Plan My Garden planner uses the same one plant per 1 x 1 foot cell. University extension guides space cauliflower wider, from 12 inches at the tight end up to 24 inches, so the real question is not whether 1 per square is the right number. It is whether one square gives a cauliflower plant enough room.
The spacing pattern
| Per square foot | 1 plant, in the center of the square |
|---|---|
| Inches apart | 12 inches, plant to plant |
| 4 x 4 bed (16 squares) | up to 16 cauliflower plants |
| 4 x 8 bed (32 squares) | up to 32 cauliflower plants |
| 3 x 6 bed (18 squares) | up to 18 cauliflower plants |
Cauliflower gets its own square on my square foot gardening chart, the same as broccoli and cabbage. The counts above are grid maximums, not a target. Whether a full square is realistic is the question the next section answers.
How wide extension guides actually space cauliflower
Six university extension sources give in-row spacing for cauliflower, and only one reaches down to the grid’s 12 inches:
| Source | In-row spacing | Between rows |
|---|---|---|
| Utah State University Extension | 12 to 18 inches | 2 to 3 feet |
| University of Minnesota Extension | 18 inches | not stated |
| University of Maryland Extension | 18 to 24 inches | 24 to 36 inches |
| Illinois Extension | 18 to 24 inches, wider for fall | not stated |
| Iowa State University Extension | 18 to 24 inches | 24 to 30 inches |
| Ohio State University Extension | 24 inches | 30 inches |
Only Utah State’s tight end, 12 inches, matches the chart and the planner. At the wide end, Ohio State’s 24 inches is exactly double the grid’s 12, which is 1 plant per 4 squares, a 2×2 foot block, arithmetic on the chart’s own spacing, not a separate entry anywhere. That width is not for the head: Utah State harvests heads at 6 to 12 inches across, Illinois at 6 to 8, Ohio State at about 6. The gap is leaf room. Maryland Extension has you pull three or four large outer leaves up and over the head to blanch it, and a cauliflower packed into one square has less leaf to spare for that.
Blanching: leaves and rubber bands, no sprays
Blanching keeps a white cauliflower head white by keeping sunlight off it, and every extension source gets there the same low-tech way: gather the outer leaves over the curd and hold them down with string or a rubber band. Nothing sprayed, nothing chemical. Timing varies: Iowa State ties at about 2 inches across, a tennis ball; Maryland and Illinois tie at 2 to 3 inches; Utah State calls it “silver dollar” size. Tied heads finish fast, 4 to 8 days (Maryland), 7 to 12 days (Illinois), 1 to 2 weeks (Iowa State). Self-blanching varieties skip the step; Illinois names Self-Blanche, which curls its own leaves over the head. Colored cauliflower, green, orange, or purple, skips it too. Iowa State says those cultivars do not require blanching, and Minnesota explains why: full color will not develop without sunlight. In warm weather, Maryland has you loosen the tie for air circulation.
Why cauliflower buttons or goes loose in heat
“Buttoning” is a head that stalls at about an inch across and never sizes up. Maryland Extension blames environmental stress, including overgrown transplants or hot and cold temperatures during head formation. Iowa State is more specific: prolonged temperatures below 50°F, dry soil, infertile soil, or an old, rootbound transplant can trigger it; a plant that buttons will not go on to form a usable head. Heat causes a separate failure: Minnesota Extension puts the threshold at 86°F in the day and above 77°F at night, enough to stop a crown from forming, though it can still form one once the weather cools. Ohio State calls cauliflower more heat-sensitive than other cole crops, best between 60 and 65°F and struggling above 75°F, with prolonged heat or drought stunting the curd or pushing the plant to bolt instead.
Planting the square
- Start seed indoors 6 to 4 weeks before your last frost, 1/4 to 1/2 inch deep (Utah State Extension). Direct sowing works too, timed 2 to 3 weeks before your last frost, per the same source.
- Set one transplant in the center of each square 1 week before to 1 week after your last frost. Do not let it get old and rootbound first; Iowa State and Maryland Extension both tie overgrown transplants to buttoning later on.
- Water deeply and evenly, about 1 to 2 inches a week (Utah State Extension), to avoid the wet-then-dry swings that stress the plant.
- Once the head is visible and 2 to 3 inches across, gather the outer leaves over it and tie them loosely to blanch it, unless your variety is self-blanching or colored.
When to plant cauliflower
These are the windows the Plan My Garden planner uses, counted from your average last spring frost. Turn the weeks into dates with the seed starting calendar, or enter your zip code on Plan My Garden.
| Start indoors | 6 weeks before to 4 weeks before your last frost |
|---|---|
| Transplant out | 1 week before to 1 week after your last frost |
| Direct sow | No separate week in the planner; see Planting the square above |
| Days to maturity | about 75 days |
| Frost tolerance | Semi-hardy: Maryland Extension says it takes light frosts but not heavy frosts or freezing |
Soil temperature for germination
From my Seed Germination Temperature Chart: cauliflower germinates from 40°F, does best at 65-85°F, and stops above 95°F. Days for seedlings to emerge, from the same chart:
| Soil temperature | Days to emerge |
|---|---|
| 50°F | 19.5 days |
| 59°F | 9.9 days |
| 68°F | 6.2 days |
| 77°F | 5.2 days |
| 86°F | 4.7 days |
Growing notes
The planner lists cauliflower at about 36 inches tall, the same as broccoli and taller than cabbage’s 25 inches, so give it a spot where it will not shade shorter crops. The indoor seed-starting setup is in my guide How to Start Seeds Indoors.
Where to get seed
Wood Prairie carries organic cauliflower seed, including Snowball, an heirloom at 65 days with a 6 to 7 inch head, in the range Illinois and Ohio State harvest at. Code PMG5 takes 5 percent off.
Quick questions
How many cauliflower plants fit in a 4×8 raised bed?
Up to 32 at one per square, 12 inches apart, the chart and planner spacing. Matching the widest extension spacing instead, 1 plant per 4 squares, a 2×2 foot block, a 4×8 bed holds up to 8, a 4×4 bed up to 4.
What is cauliflower spacing in square foot gardening?
One plant in the center of each square, 12 inches apart. That matches the tight end of Utah State University Extension’s 12 to 18 inch range. Other extension sources go as wide as 24 inches.
Do you need to spray cauliflower to blanch it?
No. Blanching is tying the plant’s own outer leaves over the head with string or a rubber band to block sunlight, nothing chemical. Self-blanching varieties do it on their own, and colored cauliflower is not blanched at all.
Why did my cauliflower button instead of forming a head?
Stress. Iowa State University Extension points to prolonged temperatures below 50°F, dry soil, infertile soil, or an old, rootbound transplant. University of Minnesota Extension adds that hot weather, 86°F in the day and above 77°F at night, can stop a head from forming at all. A button head does not recover once it starts.
How tall do cauliflower plants get?
The Plan My Garden planner lists cauliflower at about 36 inches tall, the same as broccoli and taller than cabbage, which the planner lists at about 25 inches.
Let the planner place them
Skip the grid math and the leaf-room guesswork. Plan My Garden is free to start: enter your zip code, draw your beds, pick cauliflower and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates.
Related: Square Foot Gardening Chart · Seed Starting Calendar · 4×8 Raised Bed Garden Layout · How Many Broccoli Plants per Square Foot? · How Many Cabbage Plants per Square Foot? · How Many Collard Plants per Square Foot?
