Onion

Allium spp.

profile iconAllium aflatunense 5801
by SB Johnny (CC BY-SA 3.0)
1 of 14
profile iconAllium aflatunense 5801
by SB Johnny (CC BY-SA 3.0)
1 of 14
The genus Alium contains the widely cultivated food crop known commonly as onion. As well as a wide range of the ornamental onions grown for summer displays. Onions are an easy to grow vegetable crop in the colder seasons because of their hardiness. They can also be grown in any soil type as long as it is well-draining and they receive a lot of sun. These are great vegetables for beginner gardeners as they do not require a lot of maintenance. Onions are most frequently a biennial or a perennial plants but they usually treated as an annual and harvested in its first growing season for the swollen, edible onion bulb. Onion plants produce chemicals called volatiles which repel harmful insects from other plants and can be used to create a natural insecticide spray when paired with cayenne pepper/red pepper​ and garlic.

Planning

Difficulty

Easy

Flowering time

Summer

Fruiting time

Summer, Winter, Spring

Harvesting

Bulbing usually takes place after 12 to 18 weeks. The bulbs can be gathered when needed to eat fresh, but if they will be kept in storage, they should be harvested after the leaves have died back naturally. In dry weather, they can be left on the surface

Propagation

Seed

Seeds are thinly sown directly at least 5 cm apart, in rows 30 cm apart. Onion sets are produced by sowing seed thickly in poor soil and the small bulbs produced are harvested and planted the following spring and grow into large bulbs

Special features

Repels harmful insects

Onions repel harmful insects from other plants

Crop rotation

Onions are light feeders, so crops should be rotated annually.

Special features

Origin

The onion is believed to have originated in Asia, though it is likely that onions may have been growing wild on every continent.

Environment

Light

Full Sun

Soil moisture

Dry

Soil type

Loam, Sand

Soil PH preference

Acid, Neutral

Frost hardiness

Tender

Uses

Medicinal

They are good for the heart and keep cholesterol in check

Edible

The bulb is edible, either cooked or raw.

Personality

Family

Amaryllidaceae

Flower colour

Multicoloured

Scent

Mild

Problems

Onions suffer from onion fly, stem and bulb eelworm, thrips, onion maggots, white rot, and neck rot. Diseases affecting the foliage include rust and smut, downy mildew, and white tip disease.