The common lilac flower is lilac, which blooms between May and June. In addition, there are many varieties with different flowering periods. Among them, the flowering period of white lilac and blue lilac is the same, both between April and May. The flowering period of Zushima is in June. The flowering period of lilac is the longest among the four seasons, from May to 10. Lilac leaves bloom twice a year, once from April to May and once from July to August.