Star-shaped leaves, pale flowers and cucumber fruit, all characteristics of wild cucumber. / Photo Credit: Bugwood.org
By the Wisconsin Department of Natural Resources
Plants that are pokey, viny or quick to spread across the landscape sometimes seem alarming when you discover them in your backyard or woods, or even when you spot them along the highway.
Wild cucumber has all these characteristics, and its growth rate has been quite prolific in some parts of Wisconsin again this year. But all of this is not as ominous as it seems.
Wild cucumber (Echinocystis lobata) is a vine native to the United States and found throughout Wisconsin. As a native plant, detections do not have to be reported to the Wisconsin DNR.
Wild cucumber prefers moist areas with some sunlight, especially along streams and rivers. / Photo Credit: Bugwood.org
The plant has maple-like, star-shaped leaves and produces pale, greenish-white flowers from July through September.
A single plant is self-fertile but can also be pollinated by bees, wasps and flies. It produces a pod-like fruit with spikes resembling cucumbers. However, the fruit is not safe for humans or pets to eat, as it can lead to an upset stomach.
Each pod produces four seeds that fall to the ground when the pod ripens. The pods may persist into the winter, becoming thin, brown shells.
Wild cucumbers are frequently found at the edges of forests and along streams or rivers. They prefer a moist environment and at least some sunlight. In wet years, they are easily noticed along highways and often stand out because of their tendency to climb trees and fences.
Wild cucumber is not necessarily harmful; it’s often considered more of a nuisance. It can be a problem when it is near young tree plantings, because its climbing vines can cover small trees. These vines are flimsy, yet fast-growing and send out branching tendrils that can prevent saplings from developing one straight leader. The plant’s growth also reduces how many of the tree’s leaves can get sunlight.
If removal is necessary or desired, it is best to pull vines out by the roots before the fruit has been established for the year.