When and How to Plant Allium Bulbs

Easy to grow and versatile, Alliums (otherwise known as Ornamental Onions) have become a popular plant for modern gardens. Available in an assortment of shades and sizes, these versatile plants are perfect for any garden, big or small.

To grow these eye-catching blooms for the late Spring/early Summer garden, Allium bulbs should be planted in early Autumn (September-October).

How to Plant Allium bulbs

  1. Pick your location

    Alliums thrive in sheltered areas that receive full sun. They do not like to be exposed fully to the elements. Depending on the height of the allium, tall alliums look great at the back of a border and small varieties are well-suited for containers.

  2. Soil type

    Alliums will grow perfectly well in a well-drained soil. They hate waterlogged soil.

  3. Planting in the ground

    Plant the bulbs at a depth of roughly 3-4 times the size of the bulb. Space larger bulbs approx. 15cm apart but smaller bulbs can be spaced about 10cm apart.

  4. Planting in pots/containers

    Deep pots are most suitable for Alliums. Simply use a multi-purpose compost in a pot with adequate drainage, and water well.

    Tip – Broken pots or stones placed in the bottom of the pot will help improve drainage.

Common Allium questions:

When should I feed Alliums?

Feed your Alliums in the spring with a potash-rich fertiliser.

How long do Alliums flower for?

Alliums usually flower for around 3-4 weeks.

What do I do with Alliums after they flower?

After the foliage dies down, you can cut the plants down to the ground and leave them or divide them.

Tip: Leave Allium seed heads after they’ve finished flowering for the garden birds to enjoy!

Our favourite Allium varieties:

Allium ‘White Cloud’
Allium ‘Summer Drummer’
Allium ‘Gladiator’

Allium Guide: When and How to Plant Them

Alliums are plants of exquisite beauty that deserve a place in perennial gardens. Easy to grow and undemanding, these ornamental bulbs come in a diverse range of colour, height and bloom times, to give you beautiful blooms from spring all the way through till summer.

Throughout this Allium blog, we will guide you through our most popular varieties, planting partners, a full planting guide and even video planting tutorials to get you ready for your autumn bulb planting.

Planting Guide

Planting time: September – December