Cauliflower and broccoli descend from the same species and look almost identical as young plants. In the kitchen and in the bed, though, they behave differently, and that is exactly what leads to the typical disappointments: small, crumbly heads, or a plant that simply stops after one harvest.
Both are easy to grow if you honour two things: feed them well without a lean spell, and harvest at the right moment. Let us start with the difference, then the care becomes logical.
One head or many florets
Both vegetables (Brassica oleracea) are really flower heads that you harvest before they bloom. The difference lies in the harvest strategy.
The cauliflower puts all its energy into one large white head. Once that is cut, the plant is done. The broccoli, by contrast, first forms a green main head and then keeps producing new, smaller side shoots from the leaf axils. Harvest regularly and you crop a broccoli plant for many weeks.
How to grow firm heads
Set out sturdy seedlings
From CW 16 to 26, plant sturdy seedlings into rich, firm soil. Both need space, about 50 cm in every direction.
Feed well and evenly
Work in plenty of compost and feed organically. Above all: never let them dry out. Drought stress is the main cause of small, premature heads.
Shade the cauliflower
As soon as the cauliflower head shows, fold a few inner leaves over it or tie them together. Without light the head stays nicely white instead of yellowish.
Harvest before flowering
Cut while the buds are still tightly closed. Once the cauliflower loosens or the broccoli shows yellow flowers, you have missed the moment.
Keep cropping broccoli
With broccoli, cut the main head with a piece of stalk. The plant then drives side shoots that you can keep harvesting over weeks.
Never thirsty, never hungry, never too late. Cauliflower and broccoli forgive no lean spell.
The core rule for headed brassicas
Frequently asked questions
Why does my cauliflower form only a tiny head?
That is buttoning, and it comes from a growth stall: drought, hunger, cold or over-aged seedlings. Provide sturdy transplants and steady, generous care without a lean spell.
Why is my cauliflower head grainy and loose?
It is over-ripe or suffered from heat and drought. Harvest while the head is still firm and smooth. Once the florets loosen and roughen, it is starting to bloom.
Can I keep harvesting broccoli after the main head?
Yes, that is its great advantage. After the main head it keeps driving side shoots from the leaf axils. Harvest them regularly and the plant keeps producing more.
Why should I fold the leaves over the cauliflower?
So that no light reaches the head. That keeps it bright white and tender. Without shade it turns yellowish and stronger in taste. With broccoli it is not needed.
How do I protect the plants from caterpillars?
The cabbage white lays its eggs on the leaves, and the caterpillars then eat holes. A fine-mesh crop net from the start keeps the butterflies and the cabbage fly reliably away.

