English ivy is a plant that is native to parts of Europe, Africa and Asia. It was introduced into the United States as an ornamental plant that's used extensively for ground cover and landscape decoration. When it spreads to natural habitats, it is an invasive species that can cause ecological damage and become difficult to control.
Hedera helix is the scientific name for English ivy. The young plant has leaves dark green leaves with light-coloured veins and three to five lobes on a vine that climb on brick walls, tree trunks and other structures by attaching with small sticky roots. The mature plant can have a trunk up to a foot in diameter. Older plants often have leaves with single lobes. The pale yellow flowers produce blackish purple fruit that many bird species enjoy.
There are several hundred cultivars of English ivy that are planted for ground cover and to decorate walls and ornamental structures. English ivy is popular for growing on trellises and framed topiaries. The plant is propagated for domesticated use from stem cuttings from plants of the desired cultivar. English ivy vines planted in shady spots with well drained soil will do well under varied climate conditions. Some cultivars can withstand severe winters, while others are better suited to milder climates.
English ivy is ideal for growing indoors in hanging pots or on indoor topiary frames. It is also an attractive addition to floral arrangements. English ivy stem cuttings can be kept in tap water until they grow sufficient roots for transplanting into pots with a well drained peat-type soil. Indoor ivy plants should be kept away from bright sunlight. They do well with indirect lighting or fluorescent lighting, although they can grow under incandescent lights.
English ivy is harmful to natural environments outside its native Old World habitat. Eighteen states report invasive English ivy as a problem, including Louisiana, Wisconsin and states on the East and West Coasts. The ivy is widely propagated by way of seeds in bird droppings and by escape from areas intentionally landscaped with the plant. The wild vine covers tree branches, choking off light and increasing damage caused by heavy snowfalls. As a wild ground cover, the vine creates a thick monoculture that blocks out competing native plants. It is also host to bacterial leaf scorch, a disease that can infect native oak, elm and maple trees.
There are no known biological controls for English ivy, so chemical or mechanical methods are the only ways to control an infestation of the plant in a natural environment. Several herbicides are approved for application on English ivy. Mechanical control techniques include cutting the vines, digging them up and mulching the forest floor to discourage renewed growth. Workers who use herbicides for English ivy management should follow label directions and safety warnings carefully, and workers cutting English ivy should wear safety goggles and use tools and ladders safely.