English ivy is an climbing plant that originated in Europe and western Asia. Also known as Hedera helix or common ivy, this evergreen plant is often spotted on walls, trees, trellises, and any other place it is allowed to climb. It's a popular landscaping plant and is often found in urban areas.
When allowed to spread, common ivy can grow into a mat that can reach a height of 6 to 8 inches (15.24 to 20.32 cm). If it finds a wall, tree, or other vertical structure to climb, it uses its aerial roots to ascent up to 80 feet (24.384 m) on the structure. English ivy tolerates air pollution, poor soil, and cold climates well, so it typically thrives in northern urban areas.
The leaves of common ivy are typically dark green and waxy. The veins on the leaves are palmate, which means that they radiate from a single point on the leaf. English ivy leaves usually have three to five lobes and a base shaped like a heart. When the ivy is exposed to sunlight, it sprouts green-yellow flowers and black fruit. If the ivy grows on the ground, however, it rarely gets enough sunlight and usually won't flower or produce fruit.
Although English ivy is usually very pretty to look at and is often used as a decorative plant in landscaping, it can cause a wide range of problems if left unattended. Ivy allowed to grow on walls for long periods of time may damage stucco or the grout between bricks. The sap or fuzzy white hairs on common ivy leaves may cause contact dermatitis in some people.
When English ivy grows in a forest, it can damage other vegetation. As the ivy grows, it may suffocate tree seedlings and climb mature trees. The weight of the ivy sometimes causes branches to break. As birds eat the fruit of the ivy, they drop seedlings, allowing the ivy to spread. English ivy is a threat to many natural habitats, such as redwood forests.
English ivy that threatens natural vegetation can be destroyed by cutting the vines from trees. Doing so kills all ivy growing on the tree. The ivy's stems and roots must also be pulled from the ground, and the forest floor must be carefully monitored for new ivy sprouts.