Last Updated on 13/04/2021 by Shannen Godwin
Easy to grow and versatile, Alliums (otherwise known as Ornamental Onions) have become a popular summer plant for modern gardens. Available in an assortment of shades and sizes, these beautiful blooms are perfect for any garden, big or small. Discover when and how to plant allium bulbs below in our gardening guide.
When to plant Allium bulbs?
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
- 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.
- Soil type
Alliums will grow perfectly well in a well-drained soil. They hate waterlogged soil.
- 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.
- 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:
Feed your Alliums in the spring with a potash-rich fertiliser.
Alliums usually flower for around 3-4 weeks.
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:
Check out some of our other blogs: