Cauliflower vs Broccoli: How the Plants plus Heads Differ
Cauliflower vs broccoli looks like a close match in the garden. Both are cool season members of the cabbage family. Broccoli forms a head of green flower buds plus later side shoots. Cauliflower forms a single white curd that needs steady growth plus shade from its own leaves.
The short answer
Broccoli heads are clusters of unopened green flower buds. After you cut the main head, side shoots follow for weeks. Cauliflower forms one white curd plus rarely sends up side shoots. It is harder to grow because cold, heat or drought can stop the head from forming.
How do cauliflower and broccoli heads differ?
University of Illinois Extension describes the broccoli head as compact clusters of unopened flower buds plus attached stem. The buds develop first in one large central head. Later they form in several smaller side shoots.
Cauliflower forms a curd at the growing point. When 2 to 3 inches of white curd shows, it is ready to blanch. Gardeners tie the outer leaves over the center to shade the head from sunburn. This stops it from turning green. Some varieties, like Self Blanche, curl their own leaves over the head.
Which is harder to grow?
Cauliflower is the harder crop. University of Illinois Extension calls it more difficult to grow than other cabbage family members. It is also more sensitive to cold than its relatives. Any interruption from extreme cold, heat, drought or plant damage can stop head development.
Broccoli is more forgiving. Utah State University Extension notes broccoli is not seriously damaged by temperatures down to 28°F. Cauliflower growth declines at 32°F or above 80°F. Both grow most vigorously below 75°F.
| Trait | Cauliflower | Broccoli |
|---|---|---|
| Head | White curd | Green flower buds |
| Blanching | Tie leaves over head | Not needed |
| Side shoots | Rarely | Yes, after main cut |
| Cold limit | Growth declines at 32°F | No serious damage to 28°F |
| Mature head size | 6 to 12 inches | 6 to 12 inches |
| Spring transplant | 1 to 2 weeks before last frost | 2 to 3 weeks before last frost |
Source: Utah State University Extension plus University of Illinois Extension.
Do both make side shoots?
No. Broccoli does, cauliflower generally does not. University of Illinois Extension notes removing the central broccoli head stimulates side shoots. These grow from the axils of the lower leaves. You can often harvest for several weeks.
Utah State University Extension notes added water plus nitrogen after the main harvest lead to many side shoots. They reach 3 to 6 inches long. Cauliflower does not ordinarily develop side shoots, so plants can be composted after harvest.
How to: step by step
- Pick fertile, well drained soil rich in organic matter.
- Plant out young, actively growing transplants.
- Space plants 12 to 18 inches apart in rows 2 to 3 feet apart.
- Water 1 to 2 inches weekly.
- Tie cauliflower leaves over the head when the curd appears.
- Cut broccoli before buds open, then harvest side shoots.
Troubleshooting
Small early heads (buttoning): transplant shock or overgrown transplants. Choose younger plants plus avoid dry soil at planting.
Cauliflower head turns yellow: sun exposure. Wrap the leaves over the head.
Broccoli shows yellow flowers: harvest came late. Cut the head while buds are still tight.
For related reading see cannabis leaf anatomy, companion plants when growing marijuana plus frost damage on cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Cauliflower, home vegetable gardening, University of Illinois Extension
- Broccoli, home vegetable gardening, University of Illinois Extension
- How to grow cauliflower in your garden, Utah State University Extension
- Broccoli in the garden, Utah State University Extension
FAQ
Why does cauliflower turn yellow?
Sun exposure. Utah State University Extension notes the head will discolor plus look yellow if exposed to the sun as it enlarges. Blanch the head by tying the leaves together when heads are the size of silver dollars. This shades the curd plus helps it stay white until harvest.
What is blanching cauliflower?
Blanching means shading the curd so it stays white. University of Illinois Extension advises tying the outer leaves over the center once 2 to 3 inches of curd shows. Heads are ready within 7 to 12 days after blanching begins. Some varieties curl their own leaves over the head, so tying is unnecessary.
Is purple cauliflower really cauliflower?
No. University of Illinois Extension notes purple cauliflower is actually a type of broccoli that is purple. It resembles cauliflower in overall appearance. Unlike white cauliflower, it does not require blanching. Grow it with the same cool season timing you would use for broccoli plus cauliflower.
Which matures faster?
It varies by variety. Utah State University Extension lists cauliflower varieties from 50 to 80 days, such as Snow Crown at 50 days. Broccoli varieties range from Packman at 50 days to Premium Crop at 65 days. Broccoli then adds weeks of side shoot harvests after the main head.
Why do cauliflower heads fail to form?
Interrupted growth. University of Illinois Extension notes plants held too long before transplanting, too much chilling or drought can stop heads from developing. Grow plants vigorously from seedling stage through harvest. Supply consistent, ample soil moisture plus side dress nitrogen when plants are half grown.
