Allium Plant Growing & Care Guide for Gardeners

Article by Dean Ravenscroft, Ph.D. - Updated 18th Oct 2023

In this Gardener's HQ guide, we'll explore cultivating Allium plants in your garden, indoor spaces, and other settings.

Garlic, Leek, Chive, Onions and Wild Onion: Cultivation & Garden Use

The common names for members of Allium include Wild onion garlic chives, and golden garlic.

They are usually grown as a hardy bulb by gardeners. Allium typically flowers from in the spring or summer, with species variations.

Giant Chives are also members of Allium, and can be grown by similar methods.

Description of Wild onion, Garlic and similar plants

The Allium genus contains plants such as Wild onion and garlic.

Members of the genus vary widely in height and can grow from between six inches to 5 feet (15 cm and 150 cm) in height.

Allium has balls of blue, pink or purple flowers. Due to variations in plant height they have many uses in the garden, and as well as the herb garden they are often used as edging and in borders. And of course many members of this genus are ideal for vegetable gardens. See my guides on How to Grow Onions from sets, Leeks, Blue Globe Onion, Flowering Onion 'Purple Sensation', Golden Garlic, Ornamental Onion and Allium giganteum.

How to Grow Chives, Golden Garlic, Wild onion and other Allium species

It is best to plant small Allium bulbs at a depth of four to six inches (9 to 15 cm) and larger ones at a depth of about 8 inches (20 cm), with a spacing of four inches (10 cm) for smaller species and up to a foot (30 cm) apart for larger species in the autumn.

Wild onion, garlic and similar species prefer partly shady conditions or full sunlight. The soil should be well drained, well composted and have a pH between 6 and 7.

Allium requires between 2 weeks and a full year to germinate. When starting Allium species off from seed indoors, the seeds should be imbibed in the fridge for four weeks in the dark, then removed to the light and kept at 57 to 61°F (14 to 16°C) in flats for a year.

They should be transplanted out individually in pots in the autumn.

Allium triquetrum (Three cornered Garlic) photograph by A.Poulos.

Caring for garlic and wild onions in the garden

Garlic, Wild onions and their relatives are easy to look after, they should be fertilised each spring, and dead flowers removed to prevent them becoming a pest.

Common Questions

How many members does the Allium genus have?

The Allium genus is large and diverse, containing about 700 species.

Do members of Allium make a good garden or landscaping plant?

Yes, Allium species, also known as ornamental onions, are popular for their striking spherical flower clusters.

Which Allium species are most frequently grown by gardeners?

Popular species include Allium giganteum (Giant Allium), Allium 'Purple Sensation', and Allium christophii (Star of Persia).

Are members of the Allium fragrant?

Yes, many Allium species have a distinctive onion or garlic scent when their leaves or stems are crushed.

What is the perfect location to grow Allium?

Allium prefers full sun and well-drained soil. They are typically tolerant of poor soil conditions.

Is Allium invasive in the USA, if so in which states?

Some Allium species can be invasive, e.g., Allium vineale (Wild Garlic), which is invasive in many parts of the USA.

How do I remove Allium from my garden?

Removal can be done by pulling or digging up the plants, ensuring to get the bulbs to prevent regrowth.

Summary

The Allium genus consists of perennial plants renowned for their globe-shaped flower clusters and are native to various regions worldwide. Alliums thrive in well-drained soil and prefer full sun exposure. They are adaptable and can tolerate different soil types. Regular watering during the growing season is important, and watering should be reduced during dormancy. Propagation can be done through division or by planting bulbs. Allium species are frequently used in borders, rock gardens, and as ornamental additions, thanks to their architectural beauty.

Allium plants add a touch of uniqueness to gardens with their distinctive globe-shaped flower clusters. Their ability to thrive in different growing conditions and their architectural appeal make them popular among gardeners. Whether used as border plants, in rock gardens, or as focal points, They help to bring a captivating aesthetic to the landscape. With their long-lasting blooms and striking forms, Allium species contribute to the visual interest and diversity of any garden design.

I hope that you enjoyed this guide on Allium. You may also enjoy the following garden growing guides: How to grow Sternbergia and Crinum plants.