The common lilac, Japanese tree lilac and lavender lady lilac are varieties of lilac trees. Common and Japanese tree lilacs require freezing winter temperatures in order to bloom. Lavender lady is a hybrid lilac tree, and it blooms in zones with warmer winters.
The common lilac is native to the Balkan Peninsula, but it has been developed across Europe and North America. The tree reaches a height of approximately 20 feet and produces a lavender-colored flower. The Japanese tree lilac plant can grow up to 30 feet tall, and its flowers bloom in white or pale yellow clusters. Blooms last for two weeks, and the tree's flowers peak later in the spring season than common lilacs trees. Horticulturist Walter Lammerts developed the lavender lady lilac tree in Los Angeles, California. The lavender lady reaches a height of around 8 feet, and its flowers are usually a pale purple.