Fall Blooming White Allium . Simply keep the plants moderately watered until they fade to yellow and begin to shrivel. This allium grows from rhizomes, rather than forming bulbs, and may be. 10 White Purple Allium Bulbs "Fluffy Dreams" Bloom Flower Onion from www.pinterest.com Dig a hole to the required depth. Alliums go in while leaves are falling. The gray green leaves stand about 6.