The Allium bulbs Caeruleum are bulbs of the blue ornamental onion. In early summer they carry small, globe-shaped flower heads in a clear sky blue. The plants grow to around 40 to 60 centimetres tall on sturdy, slender stems that do not easily fall over. It is a strong species that returns year after year.

At size 4/5 these are small bulbs, which is exactly why you plant them in larger numbers for the best effect. They suit the border, planters and pots. With 40 bulbs you create a few full pots or a generous group, with 80 bulbs a patch of blue in the border. With 160 or 320 bulbs you can plant a whole bed or a long strip along the patio; allow 30 to 50 bulbs per square metre. Combine them with other allium bulbs, for example purple varieties for a cool blue and purple scheme. You will find more greenery for outdoors among our outdoor plants.

When should you plant the Allium bulbs Caeruleum?

Plant the Allium bulbs Caeruleum in autumn, between mid-October and the end of November. The soil has then cooled below 10 °C, so the small bulbs can root calmly without sprouting. If it is not yet freezing, you can still get to work in December. Winter cold is needed to trigger flowering, so planting in spring achieves little.

When do the Allium bulbs Caeruleum flower?

The Allium bulbs Caeruleum flower in June and July. Each flower head stays at its best for about two to three weeks. In a warm, sheltered spot or in a pot flowering starts a little earlier, after a cool spring later. They also last a long time in the vase. In a spot they like, the bulbs multiply, so the group grows a little larger every year.

Care and tips Allium bulbs Caeruleum

Set the bulbs pointed end up about 8 centimetres deep, two to three times their own height, and 5 to 8 centimetres apart. This species loves lean, well-drained soil; on heavy soil, mix in grit or coarse sand. Drainage matters in a pot too: a drainage hole and a layer of clay pebbles prevent wet feet. Look for a suitable pot among our outdoor pots and baskets. The narrow foliage withers around flowering time, so plant them between low perennials or ornamental grasses that hide it. Let the leaves die back and give only pots a little bulb fertiliser in spring.

Water needs of the Allium bulbs Caeruleum

The blue ornamental onion needs little water and is better off too dry than too wet. In the garden rain is enough, except during prolonged drought in spring. In a pot, water about once a week from the first leaves and let the top few centimetres dry out in between.

Light needs of the Allium bulbs Caeruleum

A spot in full sun is ideal; there the blue is at its brightest and the stems stay sturdy. They feel at home on a south-facing edge, in a gravel garden or on a sunny balcony. In shade they flower only moderately.

Are the Allium bulbs Caeruleum toxic?

The Allium bulbs Caeruleum are mildly toxic if ingested. Like onion and garlic, they can cause problems especially for dogs and cats if the bulbs are eaten. Keep them out of reach of pets and young children, and wear garden gloves when planting if you have sensitive skin.

How will my Allium bulbs Caeruleum be shipped?

Your bulbs are carefully packed and shipped. That way they arrive safely and fresh from the grower.