Paulownia tomentosa (Thunb.) Sieb. & Zucc. ex Steud.
Empress Tree, Princess Tree, Royal Paulownia| Threat Level | Category |
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Similar Species May be confused with the following native and/or non-native species. Landscape Alternatives lists native horticultural substitutes |
Catalpa speciosa Landscape Alternatives |
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Description
Height
Princess tree grows 30-60 feet (9-19 m) tall with trunk diameter of up to 2 feet (0.5 m).Bark
Trunk has rough, light to dark gray-brown bark with interlaced smooth areas that are often shiny, becoming slightly fissured with age. The smooth brown bark of young branches has prominent white lenticels (corky dots). Wood is white.Twigs
Stout, brittle twigs are markedly flattened at nodes, and olive brown to dark brown in color. They are mostly glabrous except at the tip, around buds and along upper edges of leaf scars. Lenticels are pale, prominent, and elongated longitudinally. Pith can be chambered or hollow. Terminal leaf buds are absent. Lateral leaf buds are superimposed. Leaf scars are circular.Leaves
Large deciduous leaves are opposite and broadly ovate and heart shaped. Leaf margins are entire or shallowly lobed, and may be toothed on small plants. Leaves of adult trees are 6-16 inches (15-40 cm) long and 4-8 inches (10-30 cm) wide, though leaves of stump sprouts may be twice as large and have extra tips extending at veins to form shallow lobes. Both surfaces are fuzzy hairy and dull, light-green above, and pale-green beneath.Flowers
Large, showy, fragrant blossoms are borne in upright clusters 6-12 inches (15-30 cm) long at the ends of stout, hairy twigs. Corolla is 2 inches (5 cm) long, bell-shaped, and pale violet with yellow stripes inside, ending with five round, unequal lobes. Blooms in April-May before the leaves emerge from round, brown, hairy buds formed during the previous summer.Fruit
Woody, beaked, pecan-shaped capsules are 1.5 inches (4 cm) long, borne in terminal clusters turn from pale green to brown to black. The seed pod has four compartments that contain as many as 2,000 tiny winged seeds. The capsules mature in autumn, split in half to release the seeds and then remain attached all winter. One tree is capable of producing twenty million seeds that are easily transported in water or wind.Images
Photo: James R. Allison, Georgia Department of Natural Resources, Bugwood.orgMore images of Paulownia tomentosa
Life History
Princess tree, also known as royal paulownia or empress tree, is a showy, aggressive ornamental introduced from East Asia in the Paulowniaceae or Paulownia family. It grows rapidly in disturbed areas, including steep rocky slopes that may also be habitats for rare plants. Recently it has also been grown in plantations and harvested for export to Japan where its wood is highly valued.Paulownia can reproduce from seed or from root sprouts; the latter can grow to over 15 feet (5 m) in a single season. The root branches are shallow and horizontal without a strong taproot. Seed-forming pollen is fully developed before the onset of winter, and in spring the flowers are pollinated by insects. Seeds germinate within a few days on suitable substrate; seedlings grow quickly and flower in 8-10 years. Mature trees are often structurally unsound and rarely live more than 70 years.
Habitat
Princess trees are often found on roadsides, stream banks, and disturbed habitats, including fire sites, forests defoliated by pests (such as gypsy moths) and landslides. Its ability to sprout prolifically from adventitious buds on stems and roots allows it to survive fire, cutting, and even bulldozing in construction areas. Paulownia can also colonize rocky cliffs and scoured riparian zones where it may compete with rare plants in these marginal habitats. It tolerates high soil acidity, drought, and low soil fertility.Origin and Distribution
Paulownia is native to western and central China where historical records describe its medicinal, ornamental, and timber uses as early as the third century B.C. It has been cultivated for centuries in Japan where it is valued in many traditions. It was imported to Europe in the 1830s by the Dutch East India Company and brought to North America a few years later. Naturalized in the eastern U.S. for more than 150 years, it is also grown on the west coast. USDA hardiness zones 7-10 are most favorable. Other states where invasive: OR, LA, GA, NC, VA, KY, WV, MD, NJ, PA, CT. Federal or state listed as noxious weed, prohibited, invasive or banned: AL, CT, MA.Sources: Information on this plant page derived primarily from the Tennessee Management Manual and James H. Miller's Nonnative Invasive Plants of Southern Forests, USDA Forest Service.
Management Recommendations
Mechanical Controls
Cutting: Cut trees at ground level with power or manual saws. Cutting is most effective when trees have begun to flower to prevent seed production. Because paulownia spreads by suckering, resprouts are common after treatment. Cutting is an initial control measure and will require either an herbicidal control or repeated cutting for resprouts.Girdling: Use this method on large trees where the use of herbicides is impractical. Using a hand-axe, make a cut through the bark encircling the base of the tree, approximately 15 cm (6 in) above the ground. Be sure that the cut goes well into or below the cambium layer. This method will kill the top of the tree but resprouts are common and may require a follow-up treatment with a foliar herbicide.
Hand Pulling: Paulownia is effectively controlled by manual removal of young seedlings. Plants should be pulled as soon as they are large enough to grasp but before they produce seeds. Seedlings are best pulled after a rain when the soil is loose. The entire root must be removed since broken fragments may resprout.
Herbicidal Controls
Foliar Spray Method
This method should be considered for large thickets of paulow-nia seedlings where risk to non-target species is minimal. Air temperature should be above 65°F to ensure absorption of herbicides.Glyphosate: Apply a 2% solution of glyphosate and water plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray drift damage to non-target species. Glyphosate is a non-selective systemic herbicide that may kill non-target partially-sprayed plants.
Triclopyr: Apply a 2% solution of triclopyr and water plus a 0.5% non-ionic sur-factant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray drift damage to non-target species. Triclopyr is a selective herbi-cide for broadleaf species. In areas where desirable grasses are growing under or around paulownia, triclopyr can be used without non-target damage.
Cut Stump Method
This control method should be considered when treating individual trees or where the presence of desirable species preclude foliar application. Stump treatments can be used as long as the ground is not frozen.Glyphosate: Horizontally cut stems at or near ground level. Immediately apply a 25% solution of glyphosate and water to the cut stump making sure to cover the outer 50% of the stump.
Triclopyr: Horizontally cut stems at or near ground level. Immediately apply a 50% solution of triclopyr and water to the cut stump making sure to cover the outer 20% of the stump.