The best time to plant allium bulbs is in early to mid-autumn, ideally from September to November. This timing allows the bulbs to establish strong root systems before winter, enabling them to grow and flower well in spring and early summer. They can still be planted up to December as long as the bulbs are healthy and firm, but later planting may result in a shorter blooming period the first year. Planting in mid to late autumn gives bulbs plenty of time to settle before the cold season. If planting late, take care to loosen the soil and mulch heavily to protect the bulbs through winter. Alliums prefer sunny spots and well-drained soil, with the bulbs planted at a depth about 1-2 times their height and spaced according to their size.