Onion is perhaps the most cultivated vegetable plant in Italy, both for its organoleptic qualities and for the high content of salts and vitamins present in it. It is assumed that the origin of this vegetable is western Asia.
There are many varieties of this species that can take on different shapes and colors. For example, the winter onion (Allium fistulosum), in addition to presenting a different method of reproduction than the traditional one, also changes in appearance, not presenting the characteristic enlargement of the stem.
It is a biennial herbaceous plant with a collated root system that can reach up to one and a half meters in height. The Allium cepa is made up of many scales rich in reserve substances. Outside it is covered with a very thin membrane. The leaves are tapered and very pointed and cylindrical in shape. The inflorescence is very showy, pink or white. The shape of the flower is an umbrella and is divided into 3 main 4 parts.
Variety of onions
The varieties differ from each other both for the final use (fresh consumption, storage, industrial production for pickles), and for the external appearance. One of the most important differences is the time of harvest (spring onions in summer and autumn in winter are distinguished).
Spring-summer onions are generally white and should be eaten fresh (after harvest). They are sown in summer, transplanted in autumn and harvested the following spring. On the market there are bulbs that avoid the passage of sowing and are immediately ready for transplanting and cultivation.
Autumn winter onions must be sown in the ground in the period from early February to the end of March, while if sowing under tunnels, the seeding can be anticipated by a couple of months. In the latter case, the repackaging will take place in early spring and the harvest in the summer months. If, on the other hand, the sowing takes place later, the harvest will continue throughout the autumn.
As for the industrial varieties (pickles) they will be sown in spring and will be harvested in summer. These types of onion are generally white and have a smaller size than the onions mentioned above.