Gardening with Gary

Gardening Advice from an Expert

Bittersweet Vines

Linda writes~ I've tried growing bittersweet bushes in the past without any luck. I know you have to have a male and a female plant, but when at the garden centers, I don't see them marked. Can you tell me how to grow bittersweet bushes successfully. I live in Brainerd, MN.

A. Oriental bittersweet (Celastrus orbiculatus) is an invasive vine which needs plentiful pruning to keep it from taking over garden areas. It is a deciduous woody vine that can reach 60' depending on surrounding vegetation; fruit is green changing to bright yellow/orange once mature and is used in floral decorations; the vines damage and kill native vegetation by constricting and shading the trees or shrubs; prevalent along road sides, field edges, thickets; shade tolerant; seeds remain viable for several years, are spread after digestion by birds and other scavenging animals. Control actions must continue until seed sources are eliminated. American bittersweet is less invasive.

On a list of best plants for fall colors is American bittersweet, a vine native to North America. Bittersweet is a must-have for those serious about providing the landscape with fall color. Ask at a nursery for a pair. Spring is the best time since you can discern from the flower parts. The berries, green in summer, bear a yellow husk in early fall. Even at this stage, they provide a truly striking display of fall color, and as autumn progresses, the husk peels back, revealing an orange berry within. As if that weren't enough, the numerous leaves of the vine turn a vivid yellow.

Gardeners either love or hate bittersweet vine. Bittersweet kills trees and is difficult to eradicate from your landscape. But during the fall season, bittersweet vine puts on a display few other plants can rival. There are two vines with yellow and orange berries commonly called "bittersweet." They look very much alike. One, an innocuous vine indigenous to North America and displaying ovate leaves, is Celastrus scandens, or "false bittersweet." The other, an invasive exotic vine, whose stem bears blunt thorns, is Celastrus orbiculatus, or "Oriental bittersweet." In addition to its thorns, Oriental bittersweet's leaves are more rounded than ovate. Another way to distinguish the two is by discerning the location of the berries: the berries of C.scandens appear at the tips of the vines only, while those of C.orbiculatus grow along the vine. But the biggest distinction between the two is in terms of their environmental impact. For while Oriental bittersweet is considered an environmental menace by many, false bittersweet is becoming so rare in some areas that it is now a protected species. It is the Oriental bittersweet that threatens to kill your trees; while false bittersweet is itself threatened. C.scandens occurs naturally in the central and eastern U.S. C. orbiculatus is a native of eastern Asia, introduced into the U.S. in the 1860s. Reporting on the spread of Oriental bittersweet in the U.S., the U.S. Park Service says that it "occurs from New York to North Carolina, and westward to Illinois." The exotic bittersweet, C.orbiculatus, has spread so successfully that it is beginning to displace its native rival. Oriental bittersweet produces fruits that are a brighter shade of red, and more of them, so that birds are more likely to disperse the seeds of C.orbiculatus than C. scandens. The powerfully invasive Oriental bittersweet kills other vegetation with its engulfing vines. The germination of a bittersweet seed in the ground at the base of a tree seems harmless enough. Yet, it won't take long for the vine to make it to the tree's crown. It can be difficult to imagine a vine killing a tree, but Oriental bittersweet has done so. The vines reaching 4" in diameter wrap so tightly around victims that the trees are strangled, in a process called girdling. Even when the vine isn't strangling a plant, it envelopes it in so much shadow that it robs the plant of the sunlight required for proper photosynthesis.

Portions credited to: Landscaping at about.com