50x Ornamental, Globe Onion - Blue Allium caeruleum BlueIts nickname 'blue flowered garlic' did not just drop from the sky. This allium (Allium caeruleum) is known for its particularly bright blue colour. The globular ornamental onion thrives best in groups in the border. Plant the bulbs in the spring. In well drained soil. The flowers bloom in the spring. The bulbs can be planted in open ground or in a pot. Potted bulbs aren't frost hardy, so bring the pot indoors or protect the plant with bubble wrap.