When to Harvest Cauliflower in the UK
Quick answer:
Cut cauliflower when the head is a good size and still firm, tight and white, before the curds start to loosen or turn yellow. Summer and autumn types are ready from late July to November, and winter and spring types from late winter into early summer. Check heads every few days once they start to form, as the window is short. Cut the stem with a sharp knife, keeping a few leaves around the head to protect it.
Cauliflower asks for more attention at harvest time than most vegetables. The head, or curd, goes from perfect to past it in a matter of days, especially in warm weather. Checking often and cutting promptly makes all the difference.
Cauliflower harvest times by type
Early summer cauliflower: sown indoors in mid to late winter, ready in early summer, about three months later.
Summer and autumn cauliflower: sown in spring, ready from late July to October or November.
Winter and spring cauliflower: sown in late spring or early summer, ready from late winter into spring and early summer. These take six months or more, and some varieties, such as 'Triomphant', are grown for a Christmas harvest.
Sowing a mix of types gives heads to cut across much of the year. For sowing times, see when to plant cauliflower in the UK
How to tell cauliflower is ready
Firm and tight: the curd feels solid when pressed gently, with no gaps between the florets.
Good colour: white varieties are still bright white, with no yellow or brown tinge.
Good size: most heads are ready at around 15 cm across, though size varies by variety. Mini varieties such as 'Candid Charm' are picked at about tennis-ball size.
Don't wait for a head to grow bigger once it looks ready. If the florets start to separate or the surface turns grainy, the head is past its best and tastes bitter.
Protecting the head before harvest
A developing curd is easily spoiled by strong sun or hard frost.
In summer and autumn: snap a few of the outer leaves and fold them over the head. This shades it and keeps white varieties from yellowing.
In winter: gather the leaves up over the head and tie them loosely with string to protect it from hard frosts.
Lift the leaves every few days to check on the head underneath.
How to cut cauliflower
Use a sharp knife to cut through the main stem below the head.
Keep a ring of leaves around the curd. They protect it and help it keep longer.
Handle the head gently, as the curd bruises easily.
Unlike broccoli, cauliflower doesn't produce side shoots after cutting. Once the head is harvested, the plant is finished. Pull it up and add it to the compost heap, unless the roots are swollen with clubroot, in which case bin them.
Harvesting cauliflower in containers
Pot-grown cauliflower is cut in the same way. Heads in containers are often smaller, and they can dry out and bolt quickly in warm weather, so check them often once the curd starts to form.
For more detail, see growing cauliflower in containers
If several are ready at once
Cauliflowers from one sowing often mature together. If you have more than you can use, cut them anyway rather than leaving them to spoil. Heads keep in the fridge for several days, especially with a few leaves left on, and the florets freeze well if you blanch them first.
Heads that never formed properly
Small, loose heads, known as buttons, or heads that went yellow or grainy are usually down to dry spells, a check in growth after planting, or poor soil.
For more detail, see why cauliflower doesn't form heads and how often to water cauliflower
For the whole growing season, see how to grow cauliflower in the UK
For a related crop, see when to harvest broccoli
Common questions
How do you know when cauliflower is ready to pick?
When the head is a good size and still firm, tight and white, before the florets start to separate. Check every few days once the head starts to form, as it can go past its best quickly.
What happens if you leave cauliflower too long?
The florets start to separate and the surface turns loose and grainy. White heads may turn yellow. The flavour becomes bitter, so cut heads promptly once they're ready.
Does cauliflower grow back after cutting?
No. Unlike broccoli, cauliflower produces one head and the plant is finished once it's cut.
How do you keep cauliflower white?
Fold a few of the outer leaves over the head as it develops. This shades the curd from the sun and stops it turning yellow.
Harvest times, protection and cutting method based on RHS guidance.