The genus allium has more than a thousand species, most of them spread in the northern hemisphere; garlic, onion, leek also belong to this genus; however, there are varieties cultivated for their decorative inflorescences. They have ribbon-like foliage, usually thin and arched, of a light green color, sometimes streaked with white; the inflorescences are of various types, spherical, fan-shaped or umbrella-shaped; they contain small star-shaped flowers that bloom from late spring to late summer; generally the flowers are in shades of pink, white, yellow and blue.
Cultivation is very easy and the bulbs are suitable for growing wild; the flowers bloom on long stems, from 20 to 100-120 cm high, and can be cut or dried for winter compositions. We remember Allium cristophii with large spherical inflorescences, with a diameter close to 20 cm, and metallic blue flowers; Allium beesianum, small blue inflorescences; Allium schenoprasum, the common chives, with small pinkish inflorescences; Allium triquetum, with white flowers, in umbrella inflorescences. Many of the ornamental varieties emanate the typical smell of garlic or onions from their foliage or bulbs.
The garlic plants are grown in a sunny place; the bulbs do not fear the cold and can be left in the ground even during the winter months, when they completely lose their foliage. Garlic can also be grown in pots; remember to choose very capacious and deep containers for large species.
As far as watering is concerned, the allium tends to be satisfied with the water supplied by the rains; during flowering it may be necessary to water in case of prolonged dry periods.
The ideal soil for growing garlic must be soft but above all well drained. Compact soils which would cause the formation of water stagnation should be avoided. On the other hand, pot cultivation is indifferent to ground cultivation when choosing a type of soil that conforms to the needs of the plant.
The multiplication occurs by seed, or by taking the bulbils that are produced near the main bulbs; some species of garlic also produce bulbils near the inflorescences.
Garlic - Allium: Pests and diseases
Among the diseases and parasites that can affect the allium plant we remember the main ones. First of all, the downy mildew that we can easily recognize due to the numerous grayish-white signs that appear on the leaves. When the humidity is high in the environment where our seedling is located, mold will also form on these whitish spots. The immediate consequence of this disease is the rotting of the garlic leaves. To avoid the formation of peronospera, it is sufficient to water the plant in the appropriate manner required by the plant without exaggeration and to avoid water stagnation.
Another problem is given by aspergillus, a fungus that also causes the plant to rot and the appearance of a yellow dust with black dots. Also due to fungal attacks, garlic can be affected by rust with the consequent formation of yellow spots on the leaves.