Common Name: Empress Tree
Scientific Name: Paulownia tomentosa
Order: Scrophulariales
Family: Scrophulariaceae
Description This tree maintains green leaves in the summer and shades of brown in the fall. These deciduous palmate leaves are thin, flat, and obtain some leaf hairs. These leaves are also smooth, long, and have no thorns. The length of the leaves may be compared to the length of a writing pen or pencil, which is approximately four to eight inches. The leaves are common in opposite arrangement, but can also be whorled. Empress tree produces both fruit and flowers, as well. The flowers bloom before the leaves are grown. The flowering season is in spring. They bloom in April in multiple shades of purple such as lavender and violet. These flowers are radically symmetrical and are grouped together in tight clusters. They also have a somewhat vanilla fragrance. The fruits are brown and one to three inches in length when they have reached maturity. The fruits have an acorn shape, are dry, and are poisonous.
Growth Habit Empress tree is a relatively large tree that can grow 30 to 60 feet in height and up to 50 feet in width. However, the most common height ranges from 30 to 40 feet. It is also fast growing and has a trunk that can be multiple shades of brown. The trunk’s diameter may be compared to that of a coffee mug, but diameters vary. The bark is also known to peel and the limbs are known to droop. Also, the roots may come to the surface of the ground.
Hardiness Zone(s) The hardiness zones of the empress tree ranges from five to nine.
Culture This large tree requires a lot of sun and needs to be weeded regularly. Mechanical and chemical controls are often used for weed control. Pruning needs to be done on a regular basis due to the size of the tree. It needs to be in an area with much space to grow freely. An open field or park are good examples. Soil with much acid is optimal for the growth of the plant. Soils with a neutral and basic pH can also be suitable for the plant. Most soils such as sandy, loamy, clay, and well-drained consistencies are healthy for the plant, but well-drained and moist soils are best. Empress tree also tolerates atmospheric pollution.
Diseases & Insects This plant generally has no pests. The plant can actually be more of a pest to people. It is very hard to get rid of. The plants can withstand fire, cutting, and bulldozing. Squirrels and birds do not take fruit or flowers from it. Empress tree actually repels insects and pests, and is also resistant to honey fungus. A few diseases such as mildew, leaf-spot and twig canker have caused problems to the empress tree in some areas, but this is rare.
Landscape Value Empress tree is used for shade, medicines, timber, and ornamental purposes. Japan greatly values this timber and often imports this tree from the United States. It is lightweight and makes good quality furniture. Empress tree wood is used for firewood also. This wood is liked so much because it is a pest tolerant.
References Brun. C. 2015. Empress Tree. NorthWest Plants Database System, Washington State University. Online.
This document was authored by Jessica Harper, Division of Nursing, Louisiana Tech University, April 2015.