Species Spotlight: Princess Tree

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By Carter Hellenbrand, DNR Invasive Plant Field Specialist, Fitchburg;
Carter.Hellenbrand@Wisconsin.gov

Princess tree.

Princess tree growing in a hardwood forest. / Photo Credit: Nancy Loewenstein, Auburn University, Bugwood.org

Note: This is the fifth and final installment in the Forest Health News “Invasives Spotlight” 2026 series, a monthly series of Forest Health News articles.

It may have enormous heart shaped leaves, fragrant flowers and a name fit for royalty, but this botanical princess can quickly become an issue in forests.

Princess tree (Paulownia tomentosa) is a non-native invasive deciduous tree that can grow to be over 60 feet in height. It is a prolific seed producer, with individual capsules containing up to 2,000 winged seeds each. These seeds are readily dispersed by wind and waterways.

Not only does this species reproduce via seed, but it also can spread vegetatively through adventitious buds on its roots. When the tree is damaged, burned or cut, root suckers are often produced from these adventitious buds. The sprouts that form from these root suckers can grow up to 15 feet in a single growing season, resulting in more princess trees and a bigger problem.

Princess trees grow in a variety of habitats including forests, stream banks and roadsides. Due to its large leaves, typically ranging from 5 to 12 inches long but sometimes reaching 2 feet in length on juvenile trees, this species easily shades out surrounding vegetation and prevents native tree regeneration. This will ultimately lower the biodiversity of the ecosystem wherever this invasive tree is found.

History Of Princess Tree

A native of eastern Asia, princess tree was first introduced into North America as an ornamental and had been planted widely throughout the United States before becoming a regulated species.

In Wisconsin, princess tree is listed as prohibited under the Invasive Species Rule NR40. The rule makes it illegal to possess, transport, transfer or introduce this species in Wisconsin. There have been positive detections for this species in Dane, Grant, Waukesha, Milwaukee, Racine, Trempealeau and Door counties, but the overall distribution is still thought to be limited at this time.

Identifying Princess Tree

Closeup of princess tree leaves.

Large oval to heart shaped leaves of princess Tree. / Photo Credit: Nancy Loewenstein, Auburn University, Bugwood.org

Leaves: Broadly oval to heart-shaped and are very large, ranging from 5 to 12 inches long and 5 to 9 inches wide on more mature plants. Leaves can be more than 2 feet long on juvenile plants or stump sprouts.

Flowers: Bloom in early spring, tubular flowers appear in showy pyramidal clusters, are lavender in color and produce a vanilla fragrance.

Fruit: Seed is contained in clusters of green oval-shaped capsules that turn brown once mature. Each individual capsule contains up to 2,000 winged seeds.

Tubular princess tree flowers that are lavender in color and grow in clusters. / Photo Credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

 

 

 

 

 

Fruit of the princess tree.

Green, oval shaped capsules that hold up to 2,000 princess tree seeds and will change color to brown once fully mature. / Photo Credit: Robert Vidéki, Dcoronicum Kft., Bugwood.org

Lookalikes

Northern Catalpa: Tree with large heart shaped leaves that closely resemble princess tree. However, catalpa has bell shaped white flower clusters and produces long slender bean-like seed pods instead of the capsules. The center of a princess tree stem, also known as a pith, is hollow or chambered on the inside while the pith of northern catalpa is solid without chambers.

Reporting Princess Tree

There is a limited number of known populations of princess tree in Wisconsin. Eradication is still possible. If you think you have found princess tree, please report it to Invasive.Species@wisconsin.gov. At a minimum, please include the location and clear photos of the plant’s identifiable features. Other important details such as population size and landownership are also encouraged.

Lookalikes

Closeup of northern catalpa flowers

White, bell-shaped flower clusters of Northern catalpa. / Photo Credit: Dow Gardens, Dow Gardens, Bugwood.org

Northern Catalpa: Tree with large heart shaped leaves that closely resemble princess tree. However, catalpa has bell shaped white flower clusters and produces long slender bean-like seed pods instead of the capsules. The center of a princess tree stem, also known as a pith, is hollow or chambered on the inside while the pith of northern catalpa is solid without chambers.

Northern Catalpa seed pod and leaves.

Northern catalpa long and slender seed pods. / Photo Credit: Tom DeGomez, University of Arizona, Bugwood.org

Reporting Princess Tree

There is a limited number of known populations of princess tree in Wisconsin. Eradication is still possible. If you think you have found princess tree, please report it to Invasive.Species@wisconsin.gov. At a minimum, please include the location and clear photos of the plant’s identifiable features. Other important details such as population size and landownership are also encouraged.

Controlling Princess Tree

Small plants can be hand-pulled or dug up, but be sure to remove the whole root system as best you can, to keep new sprouts from developing. Due to this plant’s extensive root system, herbicide is the most effective option at removing this tree species. Cut stump applications using systemic herbicide is the most effective control technique. Be sure to read the full directions on the herbicide label to determine mixing ratios, application rates and required safety measures.

Pitch Borer Mass On White Pine

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A pitch mass on a tree's main stem.

A pitch “glob”, with oozing pitch running down the trunk of a young white pine infected with pitch mass borer. / Photo Credit: Wisconsin DNR

By Linda Williams, Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov, 920-360-0665

Have you seen big globs of gooey pitch on the main stems of eastern white pine trees?  Or maybe you’ve seen them on spruce?

For those with an adventurous side, grab a stick and scrape off some of that gooey glob. You might be rewarded with the sight of large larvae feeding beneath all of that goo. This is the larvae of our native pitch mass borer. Adults are clearwing moths that look a bit like wasps.

Peeling reveals a pitch borer "goo" mass on a damaged tree.

Using a stick to pry away some of the gooey pitch on a tree exposes a pitch mass borer larva underneath. / Photo Credit: Wisconsin DNR

Adults lay eggs on the bark. When eggs hatch, the tiny larvae chew into the bark and begin feeding on the inner bark. They feed enough to irritate the tree, causing more sap and pitch to be produced, which the larvae feed on.

Pitch mass borer can take two to three years to complete development, remaining in that same location throughout their life and continuously irritating the inner bark to promote continued pitch production. Pupation occurs under the glob of pitch and adults then chew their way out. Old pitch globs will harden and darken over time, remaining on the tree for a year or more before finally weathering off.

Hosts include pines (eastern white, jack, scotch and Austrian) and spruces (blue and Norway).

Management on forest trees is not necessary. Severely damaged and deformed trees can be removed during the first thinning. Management on yard trees includes maintaining healthy trees (which are less attractive to the adults), watering during droughts, avoiding pruning during mid-summer (which can attract adults to lay eggs near the fresh wounds), destroying any larvae under the globs of pitch and removing and disposing of severely infested trees.

A pitch mass borer larva on a tree.

Scraping more pitch off a tree’s main stem shows a pitch mass borer larva on the end of the stick. / Photo Credit: Wisconsin DNR

A photo showing the whitish color of some pitch mass borer larvae.

Pitch mass borer larvae can be shades of white to pink, depending on the host. / Photo Credit: Wisconsin DNR

Forest Health Staffers Plan Public Appearances

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Workers inspect a tree's health.

Linda Williams, DNR Forest Health specialist for Northeast Wisconsin, inspects a tree during a training session. / Photo Credit: Wisconsin DNR

By Art Kabelowsky, DNR Forest Health Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

Linda Williams, Wisconsin Department of Natural Resources Forest Health specialist for Northeast Wisconsin, will speak at multiple “Learn About Your Land” teaching events scheduled in September.

Continue reading “Forest Health Staffers Plan Public Appearances” →

Urban Forestry Fall Workshop: Tree Resilience: Planting, Pruning And Care

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pruners

Photo Credit: Wisconsin DNR

This Urban Forestry workshop is brought to you by UW-Madison Division of Extension and the Wisconsin Department of Natural Resources (DNR).

Join us to learn about tree biology and the standards of care that have been developed by the American National Standards Institute to help get trees off to a great start. Led by Rich Hauer, Director of Urban Forestry at Eocene Environmental Group, we will build on tree biology to discuss pruning and planting methods to optimize tree health.

This day-long workshop begins with a morning classroom session covering:

  • Biological Basis of Tree Action
  • Terms, Technology and Standards of Care Best Management Practices
  • Tree Planting, Growth and Longevity Proper Tree Pruning

Continue reading “Urban Forestry Fall Workshop: Tree Resilience: Planting, Pruning And Care” →

How Do Trees With Purple Leaves Photosynthesize?

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By Emma Kimball, DNR Urban Forestry Assessment Technician Intern

Crimson King Norway maple leaf. / Photo Credit: Van Wilgen’s Garden Center

Trees come in all shapes and sizes, but did you know they also come in all sorts of colors as well?

You may think about autumnal colors, but there are varieties of common trees with leaves that retain a purple hue from spring to fall. Trees with purple leaves such as copper beech (Fagus sylvatica ‘Purpurea’), purple catalpa (Catalpa x erubescens ‘Purpurea’) and the Crimson King cultivar of the ever-popular Norway maple (Acer platanoides ‘Crimson King’) are a gorgeous contrast to the foliage of green trees, offering aesthetic diversity to the landscape.

But how is it even possible for a tree to exist that doesn’t have green leaves? Continue reading “How Do Trees With Purple Leaves Photosynthesize?” →

Veteranization: Why Would You Age Trees On Purpose?

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By Casey Czerwonka, DNR Urban Forestry Assessment Technician Intern

It’s not every day that you learn about something that goes against your instincts that’s actually a good thing. When I read about British foresters purposefully “aging” young trees with chainsaws, I thought that was odd because usually, we’re trying to improve the longevity of our trees, not speed up the clock. Why might someone want older trees faster? For the habitat, of course! Continue reading “Veteranization: Why Would You Age Trees On Purpose?” →

Growing A Climate‑Ready, Wildlife‑Friendly Urban Forest In Eau Claire: CTMI Project

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By Jane Mohler

Trees in Eau Claire

Trees flank the pedestrian High Bridge Trail in Eau Claire. / Photo Credit: Wisconsin DNR

As co‑chair of the Chippewa Valley Biodiversity Partnership and a member of the Eau Claire Urban Forest Board, I joined the 2025-26 Wisconsin DNR Community Tree Management Institute (CTMI) to expand my skillset and take advantage of networking opportunities. CTMI is an advanced training course designed specifically for people responsible for urban forest management who do not have a degree/formal training in urban forestry and/or would like to hone their leadership and management skills. This program culminates in a final project utilizing the skills and knowledge gained throughout the 38 hours of instruction.

The shared goal was simple and urgent: help Eau Claire grow an urban forest that can handle a changing climate while supporting birds, pollinators and people for decades to come. We saw a quiet but powerful opportunity in the city’s Recommended Tree List. This “go‑to” list guides what gets planted along streets, in new subdivisions, around schools and in parks—and therefore, what our canopy will look like 30–50 years from now. Updating this list with climate and biodiversity in mind became the focus of my CTMI project. Continue reading “Growing A Climate‑Ready, Wildlife‑Friendly Urban Forest In Eau Claire: CTMI Project” →

Extending The Health Benefits Of Urban Trees

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By Dwayne Sperber, President, Wudeward Urban Forest Products & Founding Member, Urban Wood Network

felled trees near a construction site

Photo Credit: Dwayne Sperber

Wisconsin’s 2020 Statewide Forest Action Plan recognizes urban and community forests as essential tools for achieving economic, environmental, social and public health goals. To advance those goals, the plan encourages multi-sector partnerships, engagement with new audiences and the use of urban wood. A recent project at the Medical College of Wisconsin illustrates how these priorities can be realized when those who manage urban and community forests are connected with established higher-use utilization pathways and the professionals committed to recognized industry standards who support them.

During site preparation for new student housing at the Medical College of Wisconsin, trees designated for removal were evaluated to determine their highest and best use. Logs suitable for higher-use applications were preserved and directed into a standardized urban wood utilization pathway where they can ultimately become durable wood products. Continue reading “Extending The Health Benefits Of Urban Trees” →

Hydrate Your Trees As Well As Your Body!

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By: Kevin Sayers, sayersk@michigan.gov or 517-582-3209 or Lawrence Law, LawL1@michigan.gov or  313-316-4137

boy watering a spruce tree

Photo Credit: Wisconsin DNR

You don’t go anywhere in summer without your water bottle, right? In hot weather, your trees may need a drink, too, especially if they’re recently planted.

“When it’s hot and dry outside, your trees may suffer if they are not getting at least an inch of rain each week,” said Kevin Sayers, Urban and Community Forestry Program manager with the Michigan Department of Natural Resources. “Watering your trees during hot, dry spells can go a long way toward keeping them healthy.”

Deciduous trees – those that lose their leaves in fall – show drought stress through curling or drooping leaves. Leaves may “scorch,” or turn brown at the edges, fall off early or exhibit early fall color. Evergreen needles may turn yellow, then red or brown. Continue reading “Hydrate Your Trees As Well As Your Body!” →

Funding Opportunities

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rain coming down on path lined with trees

Photo Credit: Wisconsin DNR

DNR 2027 Surface Water Grant Preapplications Due Sept. 15, 2026

The DNR Surface Water Grant Program funds rivers, lakes and Aquatic Invasive Species subgrants for planning and management. The surface water grant program provides cost-sharing grants for surface water protection and restoration. Funding is available for education, ecological assessments, planning, implementation and aquatic invasive species prevention and control. With many different projects eligible for grant funding, you can support surface water management at any stage: from organization capacity development to project implementation. Funding may be used for vegetation management as it relates to improving the health of our waters. Pre-applications are due by 11:59 p.m. on Sept. 15, 2026. Final applications are due by 11:59 p.m. on Monday, Nov. 16, 2026.

Visit the DNR’s Surface Water Grant webpage for more information.

National Urban And Community Forestry Challenge Cost Share Grants Due Oct. 12, 2026

The intent of the National Urban and Community Forestry Challenge Cost Share grant program is to advance solutions to the economic, health and environmental challenges faced by communities. This year’s program focuses on advancing community tree resource utilization, which can reduce waste and create value by turning wood generated from pruning, removals, storm events and pest or disease outbreaks into useful products. These products may include lumber, slabs, furniture, flooring, biochar or other materials that strengthen local economies, reduce disposal costs and improve community resilience.

The program seeks practical, creative and replicable projects that help communities establish or expand wood‑utilization efforts. Competitive proposals will demonstrate how the project supports existing community forestry plans, applies industry‑recognized safety and tree‑care standards and delivers clear economic, environmental or workforce benefits. Projects should outline anticipated wood products, partnerships with professional or industry organizations and opportunities for job creation, training, or certification.

This program is intended for communities and their partners seeking to improve the management and use of their urban and community forests. Eligible applicants include state, local and tribal governments, nonprofit organizations, educational institutions and other community‑based partners. Additional information and requirements may be found by searching funding opportunity number USDA-FS-UCF-01-2026 on Grants.gov.

Community Forest and Open Space Due Oct. 13, 2026

The U.S. Department of Agriculture (USDA), Forest Service, State, Private & Tribal Forestry, is requesting applications for the Community Forest and Open Space Conservation Program (Community Forest Program or CFP). CFP is a competitive grant program that provides financial assistance to Indian Tribes, local governments and qualified conservation non-profit organizations to establish community forests through the fee simple acquisition of private forest land. The purpose of the program is to establish community forests by protecting forestland from conversion to non-forest uses and provide community benefits including public recreation, environmental and economic benefits and forest-based educational programs. Public access is required for all projects.

Applications are not submitted electronically via Grants.gov. The full Notice of Funding Opportunity and supporting documents (including scoring guidance and FAQs) are available under the ‘Related Documents’ tab of the listing and can be downloaded.

See the US Forest Service Community Forest website for more information about the program.

Additional information and requirements may be found by searching funding opportunity number USDA-FS-2026-CFP on Grants.gov.

Lake Superior Basin Community Forest Grants Due Dec. 8, 2026

The U.S. Forest Service is offering Great Lakes Restoration Initiative grants through the Community Forest and Open Space Conservation Program. Working with the U.S. Environmental Protection Agency, we expect to make about $3.5 million available to help communities purchase private forestland and establish community forests. Funding is open to projects in Michigan and Wisconsin within the Lake Superior basin in areas identified as a priority conservation area for the connectivity of wildlife habitat.

The Great Lakes form the world’s largest surface freshwater system and are the source of drinking water for more than 30 million people. Launched in 2010, the Great Lakes Restoration Initiative strategically targets the biggest threats to the Great Lakes ecosystem and accelerates progress toward long-term restoration goals.

Eligible applicants include federally recognized Tribes, local government entities and nonprofit organization that are qualified to acquire and manage land. Applicants may request up to $1 million through this opportunity, which must be matched by non-federal funds at a 1:1 rate. Additional information and requirements may be found by searching funding opportunity number USDA-FS-2026-GLRI-CFP on Grants.gov.