- Princess tree is a member of the Empress tree family (Paulowniaceae).
- A member of the foxglove family, princess tree is a large deciduous tree growing to 100 feet given the right conditions. The tree is most conspicuous in late spring when large clusters of pale purple to white trumpet-shaped flowers bloom before full leaf out. (5)
Leaves are arranged opposite, are simple and are heart-shaped at the base and large: approximately six to twelve inches long and four to eight inches wide. Leaves are a conspicuous dull, light green. (4)
Flowers are approximately two inches long, white to purple, and arranged in large clusters arranged at the end of stout, hairy twigs. Flowering generally occurs in late May in the Hudson Valley. (4)
Princess tree is an attractive ornamental capable of rapid spread via root sprouting and copious production of viable seed. Highly light dependent, the species is somewhat limited in the sites it can colonize, but it is capable of displacing native trees and altering community composition once established. (4)
No biological control option is currently available.
Manual or Mechanical Control
Pulling / Digging Up: Hand pulling or digging young plants is effective, if time consuming. Care must be taken to remove all of the root, otherwise, re-sprouting will occur. (1)
Mowing: Cutting or mowing not advisable due to the species’ strong tendency to re-sprout, unless performed at regular intervals throughout the growing season for several years. (1)
Girdling: Girdling alone will only cause princess tree to re-sprout. If utilizing this method, use in combination with basal bark spray or foliar spray for best results. (2)
Prescribed Fire: Princess tree is highly flammable and likely top killed by moderate to high intensity fires. However, little information on using fire as a management tool is available. What is known, however, is that princess tree will readily establish on sites post- prescribed fire burns. (1)
Prescribed Grazing: Although princess tree is highly palatable to goats and wildlife, the species’ ability to root sprout and coppice mean this management strategy has little impact on its survival. (1)
Soil Tilling: Not applicable
Mulching: No information available
Solarization: Not applicable
Hot Foam Spray: No information available
The pesticide application rates and usage herein are recommendations based on research and interviews with land managers. When considering the use of pesticides, it is your responsibility to fully understand the laws, regulations and best practices required to apply pesticides in a responsible manner. At times, the pest you seek to treat may not be on a pesticide label, requiring a 2ee exemption from NYSDEC. Always thoroughly read the label of any pesticide and consult the NYSDEC or a licensed pesticide applicator with questions.
Foliar Spray: A 2% solution of glyphosate or triclopyr is effective against princess tree. Repeat application may be necessary during the following growing season. Always read and follow all instructions on the herbicide label. (2)
Cut Stump: For larger trees, apply a 25% solution of glyphosate or 50% solution of triclopyr to the cut stump of princess tree towards the end of the growing season but before leaf senescence. (2)
Basal Bark: A 20% solution of triclopyr applied to the bark of dormant princess tree is somewhat effective in controlling infestations, although this technique is best applied with other strategies, such as a follow-up cut stump. (2)
Stem Injection: Triclopyr is effective for stem injection use. Midsummer and late winter injections are most effective, although follow-up treatment with foliar spray may be necessary to control root sprouts. Follow information on the product label for appropriate rates and instructions. (2)
Cut and Frill: Apply a 25% solution of glyphosate or 50% solution of triclopyr to cuts in princess tree’s cambium, made at a height of six to 18 inches from the ground. (2)
Pre-Emergent Spray: No information available
General management overview and recommendation
Princess tree can be managed quickly and effectively by consistent, careful hand pulling if populations are discovered early. Large populations including mature trees are best managed via a combination of mechanical and chemical means. All managed infestations should be monitored for several years to ensure no root sprouting occurs. Any new seedlings can be hand pulled and root sprouts sprayed. Even when using the most effective methods of chemical control, managed populations must be monitored— and often treated again— due to the species’ strong tendency to spread vegetatively.
Post treatment monitoring
Controlled populations should be revisited at least 2-3 times a season for 2-3 years to ensure no root sprouting has occurred and that the seed bank has been exhausted. (1)
Cut or pulled princess tree can be chipped and composted as long as no flower heads have gone to seed.