Photo: Flowering Oriental bittersweet, By Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
As the weather warms and we head outside it’s a good time to look for new invasive species.
Oriental bittersweet, a large woody vine, is most noticeable in the fall and winter because of its showy berries. But now, in late spring and early summer, is when the flowers for both male and female plants can confirm, with certainty, if it’s American bittersweet, a harmless native, or Oriental, a killer invasive.
Check out this great video: Defeating a killer vine: Oriental bittersweet management. Remember, the flowers today are where the fruit, on female vines, will mature. Male vines will have flowers but will not produce fruit, making it only possible to distinguish between male American and Oriental bittersweet right now when the plants are all flowering. You may wonder why we care if there’s male Oriental bittersweet if they don’t produce berries; turns-out it can cross pollinate with American bittersweet and that prodigy can be troublesome.
If you see flowers up and down the twig (not clustered at the end) on a suspicious woody vine it’s likely Oriental bittersweet.