Invasive Bittersweet: Plant Rant
I'd like to express my frustration about certain plants today – specifically, non-native invasive plants that pose a colossal problem. These invasive species wield the power to drive native flora and fauna to extinction, diminish biodiversity, outcompete indigenous organisms for scarce resources, and reshape habitats. The consequences extend to significant economic ramifications and profound disruptions to ecosystems. To delve deeper into these issues, check out the Naturalist Notes.
Let's zero in on one notorious offender: Invasive Bittersweet, scientifically known as Celastrus orbiculatus, previously recognized as Oriental bittersweet or Asiatic bittersweet.
Characteristics: Leaves: Simple, alternately arranged, rounded with finely toothed edges, glossy, measuring 5-13 cm (2-5 inches) in length, turning yellow in the autumn. Stems: Light brown, often marked with visible lenticels; solid white pith; capable of climbing up to 18 meters (60 feet) on trees and reaching a diameter of 10 cm (4 inches). Flowers: Small, greenish-yellow with five petals, clustered in leaf axils, blooming between May and June. Fruit and Seeds: Adorned with an outer skin that shifts from green in summer to yellow-orange in fall, enclosing a red, fleshy aril harboring 3-6 seeds; fruits form clusters in leaf axils, and the vivid fruit frequently persists on vines throughout winter.
Originating from China, Japan, and Korea, this woody vine was introduced to North America in the 1860s for its aesthetic appeal. The allure is undeniable, especially with its striking red and orange berries during the colder months – a sight that leads many to craft wreaths from its vines. Unfortunately, due to its prolific seed production and the formation of new stems from its spreading underground roots, this plant is spiraling out of control.
Its infestation is swift and alarming. Vines often ensnare shrubs or strangle trees by tightly coiling around their trunks. The weight of the vines can strain the tree canopy, causing branches to snap or trees to be uprooted.
But take heart! You too can contribute to thwarting this plant's global dominance. If each individual pitches in to manage invasive plants on their property, we can help decelerate their propagation. For woody plants like this one, fall is the optimal time for management, which conveniently aligns with the present. Several strategies can be employed to tackle this issue:
Hand-pulling seedlings: Smaller seedlings can be manually uprooted and should be disposed of in a manner that prevents re-sprouting or in the garbage.
Cutting: Sever bittersweet vines close to the ground to eliminate any growth above the cut. Note that the cut vines may take some time to disengage from trees independently. However, this method won't eradicate the plant below the cut, allowing it to regrow.
Cut-stump treatment: Apply herbicide to the outer rings of a cut stump within minutes of making the cut. A sponge paintbrush proves effective for application. Notably, this technique is most effective in fall, as spring application could result in the herbicide being expelled without significant impact. During this season, plants channel nutrients downward into their roots, making the application on the cut stump direct the chemical down into the roots. Furthermore, as the herbicide is confined to the cut stump, surrounding plants remain unharmed.
By joining forces in combatting invasive species like Invasive Bittersweet, we can help preserve the integrity of our ecosystems and protect native biodiversity for generations to come.
Submitted by Cathy Wesley, naturalist, August 2023