But if left unchecked, it becomes a bothersome, invasive weed. The ivy forms thick carpets and chokes out native vegetation. Then it creeps up trees into the canopy, flowers and forms berries. Unfortunately, birds eat the berries and disperse seeds to other locations. The climbing vines are long-lived and grow large, thick trunks.
Insects live between the bark and the vine, leading to potential problems.
As the thick green ivy creeps up and out the limbs, it cuts off light source to the leaves, which eventually kills the smaller branches. Soon, the entire limb is weighted down with vines. The weight causes the limbs to break. This is not just a problem in private landscapes when ivy is left unchecked. Ivy covers many forest floors and climbs trees in public parks and recreation areas.