Snowball Turnip
A round turnip with smooth skin and white, dense, juicy flesh.
About the variety. Fast-growing, it is most flavourful when harvested young and tender; the young leaves can also be used as cooking greens. The roots weigh around 200–300 g.
Itinerário técnico
Um guia de cultivo passo a passo, da sementeira à colheita.
Always sow direct where it is to grow, one or two centimetres deep in rows, because transplanting deforms the root. Germination takes four to seven days. Thin early to ten or fifteen centimetres between plants, once the seedlings have two true leaves. Failing to thin is the number one reason for harvesting turnips the size of a finger. Sow from February to April and from August to October; autumn sowings give the sweetest roots.
It wants loose, deep, stone free soil with no fresh manure, at a pH between 6.0 and 7.0. Compacted or cloddy soil gives forked, deformed roots. Work the ground to twenty five centimetres and break the clods down well before sowing. Rotate away from other brassicas.
It is a cool weather crop, ideal between 10 °C and 20 °C, and the root sweetens after a spell of cold. Strong heat makes the root hot tasting, fibrous and hollow inside. 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.
Do not use fresh manure or strong nitrogen feeding: that gives forked, hairy and tasteless roots. Use a bed that was composted for the previous crop and top up potassium only, with sieved wood ash, which improves sweetness and keeping quality.
Water regularly and without gaps. Alternating drought and heavy watering splits the roots and makes them fibrous and hot. Steadily moist soil gives tender sweet roots. In autumn and winter rain is usually enough; in summer water two or three times a week.
The crop germinates fast, but in the first weeks the seedling is small and loses the contest with weeds. Prepare the bed in advance, clear the first flush of weeds before sowing and hoe between the rows as soon as the rows can be seen. Hoe shallowly between the rows and never pile soil over the crown.
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.
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 that never drops below 6.0, 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.
Harvest young, when the root is five to eight centimetres across: that is where the flavour is. Past that it goes fibrous, hollow and hot. Pull by the leaves after watering, while the soil is damp. The young leaves are also good eating and should not be wasted. Allow about 60 to 70 days from sowing to the first harvest of this variety. The reference colour is white, and that is what tells you it is ready.
