In addition, known as tulip poplar or tulip magnolia, tulip tree (Liriodendron tulipifera) is a fast- growing tree that quickly reaches heights of between 70 and 90 feet with a trunk diameter between 4 and 6 feet. The tree towers to a height of 150 feet or more in ideal growing conditions, although smaller cultivars are available.
Tulip poplar has a conical or broad columnar habit made up of broad, squarish, bright-green leaves about 6 inches long. The thick trunk has light-gray bark. The delicate, cup-shaped flowers resemble open tulips and are about 2 to 2-1/2 inches long. The flowers, which bloom in spring or summer, are pale, greenish-yellow tinged with orange marks. Brown, cone-shaped fruits follow the flowers in the autumn.
Several tulip tree cultivars are available in the nursery trade. Cultivars include compact varieties such as Ardis and Compactum and the variegated Aureomarginatum, a variety that grows to 80 feet tall producing green leaves margined with greenish yellow. Rare varieties include Fastigiatum, a narrow tree that grows to be up to 60 feet tall with a spread of about 20 feet, and the nearly rectangular-leafed Integrifolium.
Tulip tree is a native of the Eastern United States, growing from New England south to Central Florida and west to Michigan. The tree occurs naturally in mountain coves, bottomlands and where fertile, moist soils prevail. In landscapes, the tulip tree is sometimes grown in golf courses and college campuses and other areas where it’s huge size can an asset. The tree grows in U.S. Department of Agriculture Plant Hardiness Zones 5 to 9 in either partial sun or full sun.
The tulip tree does best when grown in a deep, fertile soil that is kept consistently moist. A slightly acidic soil is ideal. The tree suffers if grown in hot, dry sites and may develop yellowing leaves. Watch for common magnolia pests, such as magnolia scale and aphids, which attract a black, sooty mold. Wash aphids away with soapy water or release predatory insects. Treat scale with horticultural oil. The species propagates by seed, although cultivars must be grafted.