Allium 'Purple Sensation' with Aquilegia
Allium is a genus of plants of the well known onion family - Alliaceae. Onions are grown as ornamentals and herbs but also for food. Allium is a herbaceous perennial plant that grows from a bulb. Sometimes the bulbs are clustered as in Allium ascalonicum (shallot). Allium flower appears in white, yellow, purple and blue.
They prefer open, sheltered, sunny positions and well drained soil.
Alliums are good to fill up the gaps in a spring border. They do not need a lot of space for their leaves are close to the ground and the flowers form on a single stem that grows straight up. Many of them are self seeding, but you can collect the seed and sow it immediately in a cold frame to stay outside over the winter. They need a period of cold to germinate. You can keep the seeds in the refrigerator for six weeks before sawing if you sow the seeds in spring. Immediate sowing is better. It may take up several years before the bulb reaches the flowering size. However, the alliums grown from seed will not come true to the mother plant.
Some alliums form small bulbs in the flower heads. That is the vegetative way of reproduction, and the new plants will be the same as the mother plant.
Allium schoenoprasum; well known herb. I divide the clump every three years.
Allium ursinum; native to Croatia. It grows in woods in moist and fertile soil. The leaves and bulbs are edible and used as medicine plant too. I brought a few bulbs from the woods into my garden some years ago and it spreads quickly. Make sure to have plenty of space for it. It may appear on unexpected places in the garden because the seeds are carried away by the ants.
Allium bulb should be planted in autumn. Large bulbs need to be about 25 cm apart, the smaller 6-8 cm. Plant them at the depth three or four times the diameter of the bulb. Lift, divide and replant large clumps when the leaves and flowers die down.