Species Management and Control Information

Princess-tree
Paulownia tomentosa (Thunb.) Sieb. & Zucc. ex. Steud.

GENERAL MANAGEMENT CONSIDERATIONS:

The Nature Conservancy - Invasive Species Initiative - Weed Notes: Paulownia tomentosa - http://tncweeds.ucdavis.edu/esadocs/paultome.html - Author: Mandy Tu - December 2002.

Summary: Paulownia tomentosa can be controlled most effectively using an integrated management approach. Cutting or girdling trees with power or manual saws are effective at preventing seed production, but repeated cutting or a herbicide treatment is necessary following cutting since Paulownia readily resprouts.

MANUAL AND MECHANICAL CONTROL:

Plant Conservation Alliance - Alien Plant Working Group - Weeds Gone Wild - Fact sheet - Princess-tree - http://www.nps.gov/plants/alien/fact/pato1.htm - Authors: Tom Remaley - April, 2004.

Hand pulling may be effective for young seedlings. Plants should be pulled as soon as they are large enough to grasp. Seedlings are best pulled after a rain when the soil is loose. The entire root must be removed since broken fragments may resprout. Trees can be cut at ground level with power or manual saws. Cutting is most effective when trees have begun to flower to prevent seed production. Because Princess tree spreads by suckering, resprouts are common after cutting. Cutting should be considered an initial control measure that will require either repeated cutting of resprouts or an herbicidal treatment.

Girdling is effective on large trees where the use of herbicides is impractical. Using a hatchet, make a cut through the bark encircling the base of the tree, approximately six inches above the ground. Be sure that the cut goes well below the bark. This method will kill the top of the tree but resprouts are common and may require a follow-up treatment with a foliar herbicide.

Southeast Exotic Pest Plant Council - Invasive Plant Manual - Princess tree - http://www.se-eppc.org/manual/princess.html -2003

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.

The Nature Conservancy - Invasive Species Initiative - Weed Notes: Paulownia tomentosa - http://tncweeds.ucdavis.edu/esadocs/paultome.html - Author: Mandy Tu - December 2002.

Hand pulling: Young seedlings of Paulownia can be successfully controlled by manual removal. Pulling is easiest following a rain event, as the soil becomes loose. It is important to remove all root fragments as Paulownia can resprout from root fragments.

Cutting and Girdling: Cutting of Paulownia trees is most effective at the onset of flowering. Cutting at ground-level can prevent seed production for that year, but cutting alone must be repeated for several years to successfully kill the tree. Girdling results in top-kill of that stem, but may also induce increased resprouts. Cutting and girdling followed immediately by a herbicide application (cut-stump, hack-and-squirt) has good rates of efficacy.

CHEMICAL CONTROL*:

Plant Conservation Alliance - Alien Plant Working Group - Weeds Gone Wild - Fact sheet - Princess-tree - http://www.nps.gov/plants/alien/fact/pato1.htm - Authors: Tom Remaley - April, 2004.

Princess tree seedlings and small trees can be controlled by applying a 2% solution of glyphosate (e.g., Roundup) or triclopyr (e.g., Garlon) and water plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce damage from spray drift on non-target species. Glyphosate is a non-selective systemic herbicide that may kill non-target plants that are only partially sprayed. Triclopyr is a selective herbicide for broadleaf species. In areas where desirable grasses are growing , triclopyr can be used with minimal non-target damage.

Girdling is effective on large trees where the use of herbicides is impractical. Using a hatchet, make a cut through the bark encircling the base of the tree, approximately six inches above the ground. Be sure that the cut goes well below the bark. This method will kill the top of the tree but resprouts are common and may require a follow-up treatment with a foliar herbicide.

The cut stump method, that is applying herbicide to freshly cut stumps, should be considered for individual trees or when desirable plants are nearby that might be impacted by foliar applications. Stump treatments can be used as long as the ground is not frozen. Begin treatments by horizontally cutting stems at or near ground level. Immediately apply a 50% solution of glyphosate or triclopyr and water to the cut stump making sure to cover the outer 20% of the stump. Basal bark applications are effective throughout the year as long as the ground is not frozen. Apply a mixture of 25% triclopyr and 75% horticultural oil to the base of the tree trunk to a height of 12-15 inches from the ground. Thorough wetting is necessary for good control; spray until run-off is noticeable at the ground line.

Southeast Exotic Pest Plant Council - Invasive Plant Manual - Princess tree - http://www.se-eppc.org/manual/princess.html -2003

Foliar Spray Method: This method should be considered for large thickets of paulownia seedlings where risk to non-target species is minimal. Air temperature should be above 65°F to ensure absorption of herbicides.