Purple Sensation Persian onion (Allium aflatunense 'Purple Sensation') is one of the earliest of the large-flowered, hardy onions that produce hundreds of violet-purple flowers in a globe-like inflorescence up to 4 inches in diameter. Each bloom spike can reach 30 inches in height. Cut flowers usually last three weeks or more in the vase, and the dried flowers retain their color well. Honeybees love the nectar produced by the flowers, and the strong onion smell of the crushed stems and leaves discourages deer and rabbits. Successful establishment in Chicago-area landscapes is dependent on planting the large bulbs among shrubs and perennials that are in active growth in mid- to late summer to prevent excess moisture in the soil from rotting the bulbs. Recent DNA analysis has found that almost all of the large, purple-flowered ornamental onions sold in the Dutch nursery trade share a common set of ancestral species, and many catalogs these days will list this variety under the name Allium × hollandicum 'Purple Sensation'.