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A picture of a Allium

Allium

Allium spp.

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Also known as

Onion

Allium aflatunense 5801 by SB Johnny (CC BY-SA 3.0)

Full Sun
Easy care
Light watering
Tender

H1a

RHS hardiness

15°C

Minimum temperature

Expected size

Height
Spread

2m

Max

1m

50cm

Min

50cm

3 years to reach maturity

Flowering

    • spring
    • summer
    • autumn
    • winter

    This plant has a mild fragrance

    More images

    Allium senescens
    PurpleBallFlower
    Allium wallichii GotBot 2015 004
    Allium fistulosum 2
    Allium rotundum 290608

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    Overview

    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.

    Common 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.

      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.

      Uses

      Medicinal

      They are good for the heart and keep cholesterol in check

      Edible

      The bulb is edible, either cooked or raw.

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