Cauliflower Di Sicilia Violetto
A stunning purple-headed cauliflower, a rare sight in the garden.
About the variety. Produces unique purple heads weighing between 2 and 3 kg, occasionally showing intermediate traits between cauliflower and broccoli. Easy to grow, especially when sown mid-way through the usual growing season.
Itinerário técnico
Um guia de cultivo passo a passo, da sementeira à colheita.
Sow in trays one or two centimetres deep at 15 °C to 20 °C and transplant at four to six true leaves, without letting the plant get pot bound. It is the least forgiving brassica: any check from cold, drought or late transplanting gives tiny loose heads, the so called buttoning. For a winter harvest, sow between June and August; spring sowings only work where the summer is cool.
It wants firm, deep soil, rich in organic matter and never acid: the ideal pH is between 6.5 and 7.5, and acid soil invites clubroot. It likes settled rather than fluffy soil: firm the ground lightly around the plant after transplanting. Minimum four year rotation away from any other brassica, radish, turnip and rocket included.
It wants cool steady weather, between 15 °C and 20 °C, without big swings. It is the brassica most sensitive to heat and to erratic weather, which makes autumn the best season across most of the Iberian Peninsula. The Portuguese coast offers close to ideal conditions and allows harvests over much of the year. Inland in Portugal and Spain, concentrate the crop in autumn, winter and early spring, because from June onwards heat and long days push it to bolt and turn bitter. In France it grows easily from spring to autumn, and in Germany the whole summer works because it is rarely too hot. Light shade over the middle of the day extends the harvest in any warm climate.
This is a hungry crop. Work two to three kilos of well rotted compost into each square metre before planting, with a handful of wood ash for potassium. Once growth is away, feed with a liquid organic fertiliser every two or three weeks, moving from a balanced formula to a higher potassium one as cropping begins. Avoid excess nitrogen, which gives lush leaves, a poor crop and a lot of aphids.
It needs constant moisture from start to finish, more than any other brassica. Water generously and never let the soil dry out while the head forms. Mulch the soil with straw to stabilise moisture.
Hand weed in the first weeks, while the plant is small and loses every contest for light and water. Once it is established, mulch with five to seven centimetres of straw, dried grass or leaves: it holds weeds back, keeps moisture in and stops rain splashing soil onto the lower leaves, which is how most diseases begin. Always hoe shallowly so you do not cut the roots running just under the surface.
Flea beetle, a small jumping beetle, riddles young leaves with round holes in hot dry weather: keep the soil moist and cover with fine mesh from sowing. Cabbage white caterpillars and diamondback moth eat the leaves from within: apply Bacillus thuringiensis while the caterpillars are small and check the underside of the leaves every week. Cabbage root fly lays at the collar and the larva destroys the root: a cardboard or felt collar around the stem stops the egg laying. Grey cabbage aphid forms waxy colonies on the shoots and is dealt with using potassium soap. A fine insect mesh put on at planting solves almost all of these problems at once.
Clubroot is the most serious disease: it deforms the roots, the plant wilts, and the fungus persists in the soil for close to twenty years. Prevent it with a four to five year rotation, good drainage and a pH above 7.0, corrected with lime. Alternaria makes dark concentric spots and downy mildew a grey bloom on the underside of the leaf; both like humidity, so space well and water at the base. Black rot enters at the leaf margins as a yellow V and is carried by seed and irrigation water. Clear all crop debris at the end and keep it out of the compost heap.
Cut when the head is firm, compact and still smooth, before the curds begin to separate. In white varieties, fold two outer leaves over the head to shade it and hold the colour. Once ready, a head opens within days, so check daily at the end of the cycle. Allow about 90 to 120 days from transplanting to the first harvest of this variety. The reference colour is purple, and that is what tells you it is ready.
