Plant: Tallow tree also known as Chinese tallow tree, or Popcorn tree (Triadica sebifera or Sapium sebiferum), is native to Asia.
Identification: A deciduous tree that can grow 60 ft tall and 3 ft in diameter has a light gray and fissured bark. Branches are light green turning gray with scattered brownish dots (lenticels) that later become striations. Alternate, broadly ovate leaves have a rounded, wide-angled base and an attenuated tip. Leaves, 2 to 3 inches long and 1.5 to 2.5 inches wide, are dark green with light green veins that turn yellow to red in the fall. Tiny, dangling, yellowish flowers, 8 inches long, appear from April to June. The flowers have yellowish green sepals but no petals. Female flowers are at the base while male flowers are along the spike. Seeds, with 3-lobed capsules, appear from August to January in small clusters at branch terminals. They are dark green in the summer becoming dry and black, splitting to reveal 3 white wax-coated seeds (resembling popcorn) that remain attached until winter.
Ecology: Tallow tree invades stream banks, riverbanks, and wet areas like ditches as well as upland sites. It thrives in both freshwater and saline soils. Tallow tree is spreading widely through ornamental plantings and bird-dispersed and water-dispersed seeds. It also colonizes by root sprouts.
Herbicide Control: For large trees, make stem injections using a 42+% active ingredient of imazapyr (Arsenal AC, Vanquish, or Polaris AC), or a 44.4% active ingredient of triclopyr (Garlon 3A or Tahoe 3A) or a 41% active ingredient of glyphosate (Accord, Razor, or Roundup Original) in dilutions and cut spacing specified on the herbicide label (anytime except March and April). Alternatively, cut and immediately treat stumps using a 44.4% active ingredient of triclopyr or a 41% active ingredient of glyphosate as a 20% solution (2 quarts per 3-gal mix) in water. For saplings, apply 60+% active ingredient of triclopyr (Garlon 4, Remedy, or Tahoe 4E) as a 15% solution (58 oz per 3-gal. mix) in a surfactant (basal oil, methylated seed oil, or vegetable oil) with a penetrant (check with herbicide distributor) or undiluted Pathfinder II to young bark as a basal spray. For seedlings and saplings, apply from July to October a 42+% active ingredient of imazapyr as a 1% solution (4 ounces per 3-gal. mix), or a 41.5% active ingredient of fosamine ammonium (Krenite S) as a 20% solution (5 pints per 3-gal. mix), or a 60+% active ingredient of triclopyr as a 2% solution (8 ounces per 3-gal. mix) in water with a surfactant at 1% solution (4 ounces per 3-gal. mix) to thoroughly wet all leaves.
Warning: Other herbicide products such as Clearcast, Habitat, Velpar L, and Stalker can also be used to control tallow tree. The active ingredients of imazapyr and hexazinone can injure or kill plants with roots in the affected area. Always read and follow label directions carefully.
Source: (A Field Guide for the Identification of, A Management Guide for) Invasive Plants in Southern Forests, James H. Miller, USDA Forest Service, 2010. Photo Credit: Cheryl McCormick, The University of Georgia, ForestryImages.Org