Skip to main content
A picture of a Allium


Allium spp.

Also known as


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

Full Sun
Easy care
Light watering


RHS hardiness


Minimum temperature

Expected size








3 years to reach maturity


    • spring
    • summer
    • autumn
    • winter

    This plant has a mild fragrance

    More images of Allium

    A photo of Allium
    A photo of Allium
    A photo of Allium
    A photo of Allium
    A photo of Allium

    Allium 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 with Allium

    How to harvest Allium

    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

    How to propagate Allium


    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 of Allium

    Repels harmful insects

    Onions repel harmful insects from other plants

    Crop rotation

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

    Other uses of Allium

    Grown for their seed heads which may be dried for winter decoration.


    They are good for the heart and keep cholesterol in check


    The bulb is edible, either cooked or raw.

    Spring Bulbs for Autumn Planting

    Plant out these flowering bulbs in autumn to enjoy their performance next year.

    Explore all

    Purple Flowering Summer Plants

    Love purple flowers and looking for summer inspiration.

    Explore all


    About usCareersPrivacy policy

    Candide is your guide to visiting UK public gardens. Find the best gardens, buy tickets and enter with just your phone. Download the app for offline tickets, community access and more.

    Terms & ConditionsCode of Conduct

    © 2023 Candide

    Made in Bristol