Spinach are biennial plants, grown as annuals, belonging to the amaranthacee family; there is only one species of spinach, whose botanical name is spinacia oleracea, and is native to central and western Asia. In Europe spinach has been cultivated for centuries, it was the Saracens, at the time of the conquest of Sicily and Spain, who introduced it to European cuisine, but only in the following centuries did they become among the most cultivated vegetables. As biennial plants, spinach is not afraid of the cold, and can therefore also be grown during the winter months, when there are few vegetables in the garden. The ease of preservation of the frozen product, without losing most of the flavor and nutrients, has made spinach a very popular and cultivated vegetable, even by the canning industry.
Spinacia oleracea are small plants, which do not exceed 25-30 cm in height; they make up a dense rosette of leaves, more or less thick or bullous depending on the variety. Typically, from sowing to harvest a month or a month and a half passes, depending on the season. If left to grow without care, the spinach produces a thin fleshy stem, covered with ever smaller leaves, and branched enough, which will bring the small greenish flowers. To have tender and crunchy leaves, the plant must not go to flower, picking up the plant before it happens. The spinach leaves are collected by detaching the outermost ones of the rosette, during the development of the plant, or by collecting the whole head, cutting the root at the base.
Variety of spinach
As we said before, although in the world there are other plants used as spinach (an example above all, beets), there is only one and only species of spinach; this means that all the spinaches we find on the market are leaves taken from spinach oleracea plants. If we go to the supermarket, however, we will notice very different spinach: spinach to eat raw, in salad, have small and smooth leaves; frozen spinach have thin leaves; fresh spinach, suitable for consumption only after cooking, have showy bullous leaves. These differences are due to the different cultivars spread in cultivation; in general spinach are plants suitable to be cultivated in short days, that is from September to April-May, however there are varieties that prefer the warm spring climate, others that prefer the winter climate. In general, spinach is divided into three different groups of varieties; the most common are the "Savoy" spinach, they are the ones we find to cook, with large, thick leaves, which present showy boils on the entire page of the leaf. "Semi-Savoy" spinach are also very widespread, that is varieties directly deriving from the previous ones, with thinner and less bullous leaves, generally very cultivated in family gardens, and often those that we find already washed and frozen; the leaves of these spinaches are less thick and fleshy, and are therefore easier to treat, wash and pack. The latest varieties are those of smooth leaf spinach; the leaves are smaller, thin and delicate, and are definitely more suitable for raw consumption. It is often mistakenly believed that the smooth spinach leaves are the young ones, in reality the savoy plants have bullous leaves even when they are of small size, while the smooth leaf varieties, have smooth foliage even in the "old" plants, that is ready for the collected.