Allium

Where does the Allium come from?

The genus Allium probably includes more than 1,000 species and cultivars. This plant is naturally spread across the Northern Hemisphere and is common in Central Asia, the countries around the Mediterranean and western North America. Allium grows mainly in these areas because of the favourable climate and soil conditions. However, we also find some wild Allium species in the Netherlands, such as the sage garlic (Allium sativum).

From small bulbs to large ornamental onions

The diversity in the Allium genus is truly astonishing. Many original and cultivated species have a bulbous base that varies from small (about 3 cm) to large sizes of up to 40 cm. These bulbs store nutrients and ensure a long flowering period, which makes the Allium ideal for use in the garden. In addition, there are species with a thickened root base, also called a 'shaft', which are also suitable for naturalisation and long-lasting flowering.

Small and large bulbous Allium

Alliums can be roughly divided into two main groups: small bulbous and large bulbous Alliums. Smaller Alliums and varieties with thickened roots are very suitable for naturalisation and grow well in a natural environment. Larger species, such as the giant onion (Allium giganteum), can remain in the ground for several years, although the flowering quality may decrease over time. These larger bulbs will last the longest in permeable sandy soil.

Care and maintenance of Allium bulbs

Caring for Allium bulbs is relatively simple, but there are a few important points to consider. If you notice that the flowers are getting smaller over the years, you may want to consider removing the bulbs from the ground after flowering. To preserve them, it is important to store them at a temperature of around 23-25 degrees Celsius. This prevents them from drying out and ensures that the bulbs retain their vitality. Replant the bulbs in November, preferably in a different location, to prevent diseases.

Tips for planting Allium

Alliums like a sunny location and well-drained soil. It is advisable to plant the bulbs in the autumn, so that they can flower in the spring or early summer. For long-lasting flowering and a stronger plant, it is advisable to plant the bulbs a few centimetres deep. For large-bulb Alliums such as ornamental onions, a planting depth of around 10-15 cm is ideal.

Frequently asked questions about Allium

Can Allium survive in The Netherlands?

Yes, many Allium species thrive in the Dutch climate. They are hardy and can adapt well to local soil and weather conditions.

• Wild varieties, such as garlic sage (Allium ursinum), are especially resilient and tend to naturalize easily.
• Most ornamental Alliums prefer well-drained soil and full sun but tolerate partial shade.
• Winter frost generally does not harm the bulbs, but heavy, wet soils can cause rot.

How often should I move my Alliums?

Most large-bulb Alliums can stay in the samen place for several years without any problems. Relocating them is only necessary when flowering decreases or the bulbs become crowded.

• If the flowers are smaller of fewer each year, it may indicate nutrient depletion or overcrowding.
• Moving the bulbs to a different location can help prevent disease and encourage more vigorous blooms.
• Smaller or more delicate, such as Allium moly, often benefit from being replanted every 2-3 years.

When is the best time to plant Alliums?

The best planting time for most Alliums is autumn, before the first frost, allowing the bulbs to establish roots before winter.

• Spring planting is possible for some species, although flowering may be delayed.
• Ensure the soil is well-draining to avoid bulb rot over winter.
• Bulbs should be planted at a depth roughly three times their own height.

How should i care for Allium flower after blooming?

Deadheading Allium flowers can improve the plant’s appearance but is not strictly required.

• Leaving the flower heads in place allows seeds to form and potentially self-sow fort he next season.
• The foliage should be left to die back naturally because it nourishes the bulb for next year's growth. 
• Avoid cutting the leaves while they are still green can weaken the bulb and should be avoided.

Can Alliums attract pollinators?

Yes, Alliums are excellent for attracting bees, butterflies, and other pollinators.

• Larger, globe-shaped varieties provide a rich nectar source during summer.
• They fit well into pollinator-friendly gardens, especially when combined with herbs and flowering perennials.
• Growing a variety of Allium species can extend the blooming season and offert pollinators support for a longer period.

Buy Alliums online at Nijssenbulbs

Allium is a versatile plant that is incredibly popular, which, thanks to its various colours, shapes and sizes, is an enrichment for any garden. With the right care, these plants can flower for years and provide a beautiful spectacle of colours.

Would you like to order Alliums online at Nijssenbulbs? Take a look at our extensive range. If you would like help or advice with this, please contact us without obligation by calling or emailing.