When to plant cauliflowers?
Cauliflower is sown mainly from March to May, at 12-22 °C, and in January or February only the early-summer varieties, indoors. In Sicily the natural cycle of the cabbages is autumn, winter and spring; Campania sets no month and keeps growth at 15-18 °C, with looser heads above 25 °C.
When, by region
| North | Centre | South | |
|---|---|---|---|
| Sowing | Main season March to May, at 12-22 °C, seed 1.5 cm deep. January or February indoors, only for early-summer varieties. Winter varieties, from late spring to early summer. | Umbria's guide does not fix a month. Transplant at about six weeks, 10-15 cm tall. At least 2 years before returning, and no other brassicas in between. | In Sicily, an autumn-winter-spring cycle. Summer transplants to bring it forward, autumn transplants for winter and spring. In Campania, 2-3 plants per square metre, with no month. |
| Temperature | Soil at 13-16 °C. It likes cool, damp weather. Spring frost and hot, dry weather stop the head. Summer and autumn varieties are cut before the first frost. | As in the north. Umbria does not write a degree threshold. | In Sicily, between 10 and 25 °C. In Campania, 15-18 °C; above 25 °C the heads are looser. The same threshold as broccoli. |
A small head, or none, comes from a check: drought, loose soil, a late transplant, frost or heat.
March to May, January or February indoors for early-summer varieties, 12-22 °C, 1.5 cm and transplanting at six weeks, are from the RHS. Soil at 13-16 °C (55-60 °F) is from University of Minnesota Extension. The 15-18 °C, the 25 °C limit and 2-3 plants per square metre are from Campania. The autumn-winter-spring cycle, 10-25 °C and summer or autumn transplants, are from Sicily. The 2 years with no other brassicas are from Umbria. Heading broccoli is in when to plant broccoli. The months are in the January calendar, March, May and June.
A few plants at a time
They mature together. The RHS sows few, in batches about three weeks apart, from March to May. Early-summer varieties start in mid to late winter, indoors, and go out in spring under cloches. Summer and autumn varieties are sown in spring, outdoors from mid to late spring, and cut before the first frost. Winter varieties, from late spring to early summer, take six months or more.
The seed goes 1.5 cm (¾ in) deep, at 12-22 °C (54-72 °F). Transplant at 10-15 cm (4-6 in), about six weeks old, deeper than before, lowest leaves level with the soil. Summer and autumn varieties at 45-60 cm (18-24 in), rows 60 cm apart. Winter varieties at 70 cm (28 in). Mini ones at 15 cm (6 in). The seedbed is in the homemade seedbed.
A whole head, or none
The RHS lists what stops it: a late transplant, loose soil, uneven water, spring frost, summer heat. Prepare the soil firm, better from the previous autumn. The pH it gives is about 6.5. Sun yellows a white head: fold the leaves over it. In winter, tie them, against frost. Cut as soon as it is firm. Once it opens, it is late and tastes bitter.
In a pot, mini varieties: up to four in a 40 cm (16 in) pot. It dries out fast, and a check shows on the head: see the container garden. Steady water, without waterlogging, is in watering.
Rotation
The RHS does not put it back where cabbages grew for at least two years. In Umbria the gap is at least 2 years, and no other brassicas go in between: that covers cauliflower, broccoli and savoy. The plan is in crop rotation. Insect-proof mesh, pinned down, keeps out pigeons and the cabbage insects. The wider picture is in pests and diseases.
In Sicily the natural cycle is autumn, winter and spring. Summer transplants are cut in autumn; autumn transplants, in winter and spring. Compost goes on the bed the autumn before: it is in the compost guide.
In the app
Every plant in the catalogue has its own sowing calendar, and weather alerts for your area help you judge whether to sow now or hold off.
Frequently asked questions
Can I sow cauliflower in January?
Only early-summer varieties, indoors, at 12-22 °C. The RHS sows those in January or February. The main season is March to May. Winter varieties start in late spring.
Why is the head small, or missing?
The RHS ties that to a check: a late transplant, loose soil, uneven water, spring frost or hot, dry summer weather. Keep the soil firm and moist, without waterlogging.
How far apart, and in a pot?
Summer and autumn: 45-60 cm, rows 60 cm apart. Winter: 70 cm. Mini: 15 cm, up to four in a 40 cm pot. In Campania, 2-3 plants per square metre.
What month is it in the south?
No month is written. In Sicily the natural cycle is autumn, winter and spring, between 10 and 25 °C, with summer transplants to bring it forward and autumn transplants for later. In Campania growth is happiest at 15-18 °C, and above 25 °C the heads are looser.
Can I plant it where broccoli was?
Not in Umbria: at least 2 years, and no other brassicas in between. The RHS asks for at least two years with no cabbages on the same spot.