Japanese Tree Lilac will grow to be about 25 feet tall at maturity, with a spread of 20 feet. Height: Japanese tree lilac can range from 20 to 25 feet tall on average (3). Hardy to -30°F and up to 7,000 feet elevation, the Japanese tree lilac is a hardy specimen that adapts well to Colorado’s high pH soils. Whole Plant Traits: Plant Type: Shrub Tree Syringa reticulata (Japanese Tree Lilac) is a large shrub or small tree with an oval to rounded crown. - 20 ft. 0 in. It has a low canopy with a typical clearance of 5 feet from the ground, and is … Japanese Tree Lilac is a small flowering tree or large shrub in the olive family. In early summer, a profusion of huge clusters, 6-12 in. The Japanese lilac "Ivory Silk" tree grows to an average height of 25 feet, with an average width, or spread, of 15 feet, according to the University of Florida. It’s a slow-grower with a mature height of 15-25 feet and a slightly narrower spread. This tree has an oval-shaped canopy when young that gradually widens into a nicely rounded shape. Diameter: Diameter at breast height (4.5 feet) rarely exceeds 12 inches. The leaves of this deciduous tree are dark green and ovate. Japanese Tree Lilac is recommended for the following landscape applications; Accent; Shade; Planting & Growing. Plant in full sun in organically rich well-drained acidic soils. Appearance. Width: 15 ft. 0 in. The blossoms give way to loose clusters of tan capsules that persist well into the winter months. long (15-30 cm), packed with musky-scented, tiny creamy-white flowers adorn the tree for about two weeks. Japanese Tree Lilac; Phonetic Spelling si-RING-gah reh-tick-yoo-LAY-tuh Description. - 30 ft. 0 in. Canopy: The average canopy for a Japanese Tree Lilac is usually 15 to 25 feet across (6). Height: 20 ft. 0 in.