Common name: Onion, Common onion, Bulb onion
It’s unlikely that there is any other vegetable as commonly used as onions in cuisines all over the world. They are a staple in most kitchens, though there are some religious sects that forbid its use.
Onions belong to Alliums, the same family as garlic, shallots and leeks, all of them used to add flavor and warmth to dishes. The plants grow to a height of 2 feet with bluish-green, hollow, tubular leaves with white bases. The white bases of leaves arise from fruit bulbs that are formed below the surface of the soil.
These bulbs are actually modified, fleshy stems and leaves arranged in concentric layers around a central bud. The plants start flowering profusely during summer months with big balls of beautiful, white flowers held aloft by long stalks.
The flowers have both male and female organs, and are capable of self-pollination or cross-pollination by wind, bees, insects and butterflies. Common onion bulbs usually grow singly, though sometimes they are seen in twos or threes. They are harvested after the leaves brown and die, but they can also be harvested as tender onions for pickling.
The leaves are also used in cooking and can be harvested before the onion are ready. Onion plants are mostly grown as annuals, harvested together after the crop is ready. But if the onion is left in the soil, it can sprout again and form new plants. There are many variants and related species like Japanese bunching onions, Canada onions, Egyptian onions etc. with slight variations in size, taste, color and number of bulbs.
The most common types of onions are yellow or brown onions, red or purple onions and white onions. It’s a ground rule that lighter colored onions are milder in flavor and not as pungent as the darker colored ones. Onions are available in most countries in various forms like fresh, canned, diced, sliced, dried, pickled, frozen, powdered, granulated etc.
Onion are also used in dishes in various forms like fresh, sautéed, cooked, steamed, pickled, grilled, fried, braised, baked, roasted, pureed and more. The versatility of this vegetable is unbelievable. Most dishes in India are incomplete without onions; and most restaurants also give them as sides in raw or pickled forms. They are also used in soups, salads, seasonings, spreads, sauces and juices.
This wonderful vegetable also has many health benefits like reducing blood sugar, hypertension, cholesterol and stomach ailments. They have anti-bacterial and anti-cancer properties. Regular intake of onions aid in maintaining gut health and proper digestion. But they are toxic to most pets.
Propagation is through seeds and onion bulbs called sets. They are best grown in well-drained, sandy, nutrient-rich soil.