Um guia de cultivo passo a passo, da sementeira à colheita.
pH ideal 6.5 to 7.5Temperatura ideal 13 to 24 °CCompasso 10 cm in the row, 30 to 40 cm between rows
Sementeira
Sow in a seedbed or trays one centimetre deep, ten to twelve weeks before transplanting. Germination takes two weeks. Transplant when the plant is the thickness of a pencil, trimming a third of the leaves and roots, into a deep hole made with a dibber, fifteen centimetres deep: do not fill the hole with soil, only with water, and that is what produces the long white shank. Earth up through the cycle to blanch further. At around 50 centimetres tall, this variety grows well in a container. Use a pot at least twenty five centimetres deep with drainage holes, and expect to water more often, because a pot dries out far faster than open ground.
Solo
It wants deep, fertile soil, rich in organic matter and moisture retentive, at a pH between 6.5 and 7.5. It is a long crop, five to six months, so the fertility has to last. Work the soil deeply to allow for earthing up.
Clima
Very tough, it grows between 13 °C and 24 °C and stands hard frost, staying in the ground all winter without protection. It is one of the most reliable crops for harvesting in December and January anywhere in western Europe. It takes cold well and a light frost even improves the flavour, which makes it an autumn and winter crop in southern Europe. On the Portuguese coast it grows through the whole winter without trouble. Inland in Portugal and Spain night frosts do it no harm, but the summer there is too hot and dry for it. In France and Germany it is a summer and autumn crop, and in a cold winter a fleece or a low tunnel keeps the leaves in good condition well into the cold season. In Italy it is an autumn and winter crop in the centre and south, as in Portugal, and a spring and autumn crop in the north, where the Po valley winter is too hard to leave it outside unprotected.
Fertilização
This is a hungry crop. Work two to three kilos of well rotted compost or mature manure into each square metre before planting and add a handful of bone meal or wood ash to top up phosphorus and 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.
Rega
Water regularly through the whole cycle, because water shortage toughens the shank and reduces size. It is thirstier than onion. When watering, avoid splashing soil into the leaves, where it gets trapped between the layers.
Controlo de Infestantes
The crop germinates slowly and is completely overrun by weeds in the first weeks, which is the number one cause of failure. Prepare the bed in advance, clear the first flush of weeds before sowing and mark the row with radish, which comes up within days and shows you where to hoe. Hoe shallowly between the rows and never pile soil over the crown.
Controlo de Pragas
Leek moth tunnels inside the shank and is now the most serious pest: cover the crop with very fine mesh from transplanting. Onion fly and thrips also attack. Remove and destroy plants with larvae inside and use a four year rotation.
Doenças
Leek rust covers the leaves with orange pustules in damp autumns and is the commonest problem: space well, avoid excess nitrogen and remove affected leaves. Downy mildew and white rot also occur. Four year rotation away from all alliums.
Colheita
Start lifting once the shank is two or three centimetres across and go on pulling as needed through the winter. Lift with a fork, because pulling snaps the plant. Wash well between the leaves, where soil collects. It does not keep long once lifted: the best store is the bed itself. Allow about 90 to 120 days from transplanting to the first harvest of this variety. The reference colour is white stem with mid green leaves, and that is what tells you it is ready.
