Miller, James H.; Manning, Steven T.; Enloe, Stephen F. 2010. A management guide for invasive plants in southern forests. Gen. Tech. Rep. SRS–131. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 120 p.
Chinese parasoltree [Firmiana simplex (L.) W. Wight] is an increasingly planted ornamental deciduous upright tree that grows up to 50 feet (16 m) in height. It has smooth, striped trunks to 2 feet (60 cm) in diameter with stout alternate branches. Leaves can be over 1 foot (30 cm) across, dark green above and fuzzy white beneath, and mostly three-to-five lobed with petioles almost as long as the leaf. Terminal large showy clusters of tan and yellow flowers appear in midsummer to quickly yield unusual pods that split into four leaflike sections (little boats) joined at the apex with several pea-sized fruit attached along the upper margins. Round oily seeds can germinate immediately after fully formed in winter in semitropical parts of Florida and the Gulf Coastal Plain or in the spring further north. Leaves turn yellow in fall, and multibranched showy fruit stalks remain over winter into early summer. An extremely rapid growing species with variegated cultivars advertised and sold for “instant shade.” Abundant seeds per tree are highly viable and spread by wind and water to form surrounding infestations. Seedlings will persist in shade, growing rapidly tall to reach sunlight, while saplings and trees require partial to full sunlight. Many surface roots can lift sidewalks in urban plantings and sprout after tree kill. Capable of spread throughout the region.
Management strategies
- Do not plant. Advise nurseries not to sell. Remove prior plantings. Bag and dispose of fruit in a dumpster or burn, and control seedlings.
- Treat when new plants are young to prevent seed formation.
- Cut and bulldoze when fruit are not present in spring and early summer.
- Manually pull new seedlings and tree wrench saplings when soil is moist, ensuring removal of all roots.
- Burning treatments are useful for seedling and sapling topkill when leaflitter is present and fires can be hot.
Recommended control procedures
Large trees. Make stem injections using a glyphosate herbicide or Garlon 3A in dilutions and cut-spacings specified on the herbicide label. For stems too tall for foliar sprays, cut large stems and immediately treat the stump tops with a glyphosate herbicide or Garlon 3A as a 30-percent solution (7 pints per 3-gallon mix) or Garlon 4 as a 25-percent solution (3 quarts per 3-gallon mix), and add a penetrant for more effective control. ORTHO Brush-B-Gon, Enforcer Brush Killer, and Vine-X are effective undiluted for treating cut-stumps and available in retail garden stores (safe to surrounding plants).
Saplings. Apply a basal spray for trees up to 4 inches in diameter, using Garlon 4 as a 30-percent solution (7 pints per 3-gallon mix) in a labeled basal oil product, vegetable oil or mineral oil with a penetrant, or fuel oil or diesel fuel (where permitted).
Seedlings and saplings. Thoroughly wet all leaves with one of the following herbicides in water with a surfactant: a glyphosate herbicide as a 4-percent solution (1 pint per 3-gallon mix) whenever green foliage is present and when safety to surrounding plants is desired; or Arsenal AC* as a 1-percent solution (4 ounces per 3-gallon mix), or Arsenal PowerLine* as a 0.5-percent solution (2 ounces per 3-gallon mix).
* Nontarget plants may be killed or injured by root uptake.
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