Pompeii White Onion - Allium cepa

'Pompeii' onion is an early variety that produces beautiful flattened globe-shaped white bulbs with a fresh, mild flavour. Recommended for spring crops. Sow in spring or late summer and harvest from April to July.

The onion (Allium cepa) is a popular herbaceous biennial vegetable (grown as an annual) belonging to the Fabaceae family alongside chives, garlic and leeks. It is grown for its edible bulb and occasionally for its stalks. It is thought to be native to central Asia, where it has been consumed for over 6000 years. Traces of onions have also been found in Ancient Egyptian tombs. They were introduced to Western Europe much later by the Romans, then to the Americas during Christopher Columbus’s second voyage.

Bulb onions can be grouped into 3 main categories, based on the colour of their bulb:

- Yellow onions: sweet flavoured, generally the best type for storing and cooking

- White onions: fairly mild-flavoured, perfect for eating raw

- Red onions: sharp yet sweet flavour and bright colour, delicious grilled, in salads or in sandwiches

Spring onions are regular bulb onions (often white) that are harvested early, when the bulbs are still immature. If they are harvested prior to bulbing, they will often be referred to as green onions. Scallions are cultivars selected to produce a long, slender white shank rather than a bulb. Bunching onions or Japanese onions are a different species altogether (Allium fistulosum). All are fairly similar in flavour and can be substituted in recipes if need be.

Onions are an excellent source of minerals and vitamins A, B and C. They are known for their ability to reduce 'bad' cholesterol and lower blood pressure. They develop a sweeter flavour and are easier to digest when cooked. To avoid eye irritation when preparing onions, peel or chop them under the tap or in a bowl of water.

Harvesting: Harvest spring onions… in the spring, when the leaves are still green. Mature bulb onions are harvested in the summer when the onions tops are completely dried out and folded over. Gently lift the bulbs, brush off any excess soil and leave them to dry in the sun for 2-3 days.

Storage: Onions will keep for several months in the right conditions. Cut off the leaves and store the onions in a dark, cool, dry and airy place. If the leaves are strong/long enough, they can be braided together to form attractive bunches and hung from the ceiling. Before storing, check for bruising as it only takes one rotten bulb to contaminate the whole crop.

Good to know: onions and carrots are excellent companion plants as onions repel carrot fly. Onions can also be successfully grown alongside beets, strawberries and lettuce. Avoid growing onions too close to members of the Fabaceae family.