Allium Plant Growing & Care Guide for Gardeners

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.

Garlic chives

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 the plants Wild onion and garlic.

Members of the genus vary widely in height and can grow from between 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.

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

It is best to plant small Allium bulbs at a depth of 9 to 15 cm and larger ones at a depth of 20 cm, with a spacing of 10 cm for smaller species and up to 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 14 to 16 degrees celsius in flats for a year.

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

Allium
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.

Allium Growing and Care Guide

Common Names: Chives, Garlic, Wild Onion, Onion, Leek.
Life Cycle: Hardy bulb.
Height: 4 to 60 inches (10 to 150 cm).
Native: Large genus of approximately 750 species, most of which are native to temperate regions of the Northern hemisphere. But some species also derive from South America, and tropical Africa.
Growing Region: Zones 3 to 9.
Family: Amaryllidaceae.
Flowers: Species dependent: Mainly spring or/and summer. Some species in the autumn.
Flower Details: White, yellow, blue, pink. Oval. Globular. Rounded blooms.
Foliage: Usually straight. Linear. Flat. May be evergreen, but many species die away from the tip.
Plant/Sow Outside: Usually grown from Allium bulbs as hybrid varieties will not grow true from seed.
Bulbs: Smaller species: 3 to 6 inches (8 to 15 cm) deep; Larger species: 10 inches (20 cm). Autumn. Space smaller species 4 inches (10 cm) apart, and larger ones at a distance of up to 12 inches (30 cm).
Seeds: Germination: two weeks to one year. Mix seeds in a moist growing medium, place in a freezer bag, then stratify by refrigeration for four weeks in the dark. Seeds should then be sown into flats and kept in the light, at 57 to 60°F (14 to 16°C), for one year. Transplant outdoors in the autumn.
Requirements and care: Full sunlight or partial shade. Good drainage. Supply compost. Soil pH 6 to 7. Provide a spring feed. Deadhead to prevent spreading. Propagate: from offsets once flowering has finished and leaves have died back.

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 commonly known as Alliums. These plants are 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, Alliums 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.

Found the insights on this site valuable? Then you're going to love my book: 'The Gardener's HQ Plant Growing Guide'.

Purchase Now & Enjoy a Discount

Upon purchase, receive the eBook in PDF, MOBI (for Kindle), and ePub (most e-readers and iPad) formats. Also available from Amazon USA, Amazon UK, and iBooks.

Gardener's HQ