The Ivory Silk lilac tree (Syringa reticulata 'Ivory Silk') is a deciduous tree with a rounded canopy and a graceful, spreading habit. It is a cultivar of the Japanese tree lilac and can grow up to 20 to 30 feet (6 to 9 meters) tall and 15 to 25 feet (4.5 to 7.5 meters) wide.
The tree produces fragrant, creamy-white flowers in late spring to early summer that are arranged in large, showy panicles that can be up to 12 inches (30 cm) long. The flowers are followed by small, inconspicuous seed capsules that turn brown as they mature. The foliage is dark green and lustrous, turning yellow in the fall before dropping.
It's important to note that the size of the tree can be influenced by various factors such as soil conditions, climate, and pruning practices. So, the actual height and spread of the Ivory Silk lilac tree may vary depending on the specific conditions in which it is grown.