Bright periwinkle flowers bloom in early summer and develop into large, impressive clumps over time. Allium Azureum is lovely when paired with your favorite colored roses. 15 bulbs per bag. Bulb size 4-5 cm. Late blooming ornamental plants that work great with early flowering perennials. Do not plant too closely together since they multiply rapidly. Plant Alliums in full sun in early fall. Water well throughout the growing season.