English ivy is an evergreen, climbing plant native to Europe that is widely cultivated as a ground cover and ornamental plant. More than 30 varieties of English ivy, or Hedera helix, have been selectively bred for ornamental growth, states Peter Q. Rose in his book "The Gardener's Guide to Growing Ivies," emphasising unusual leaf colouration and agreeable growth habits. English ivy, although beautiful, is a toxic plant with invasive tendencies and precautions must be taken when handling or cultivating it.
Thorndale is a variety of English ivy that was bred to enhance its spreading tendency, making it a popular ground cover. Growing to a height of 8 feet, Thorndale is suited to climbing moderate slopes and trellises, as well as brick walls. Thorndale requires little water and is more cold resistant than other varieties of English ivy, which accounts for its widespread use in Midwestern gardens. It is adaptable to a variety of lighting, whether direct sun or partial shade. Thorndale has a deep forest-green colouring with cream-coloured veining and slightly lobed leaves.
Sagittifolia variegata is one of the most visually striking varieties of English ivy. Widely grown in the south of France, sagittifolia variegata is distinguished from other English ivy by its unusual colouring, which is a yellowish-green with splotches of darker green, trimmed with cream. The three-lobed leaves of this variety are especially pronounced, almost resembling maple leaves in shape. Growing to heights of 6 feet, this type of English ivy is well suited to container growth, particularly hanging baskets and window boxes. It is hardy in extreme temperatures and requires very little water, although it will benefit from occasional pruning.
One of the few truly variegated forms of English ivy, Ceridwen is sought after for its grey-green mottled foliage. It is a particularly fast-growing variety of ivy and must be regularly pruned to inhibit its tendency to dominate the garden. Due to the highly ornamental appearance of its leaves, it is a popular choice for topiaries and hanging baskets. Ceridwen prefers acidic soil with a high sand content, as well as moderate water in the summertime. The average height of Ceridwen is 8 feet, but if left to grow wild it can exceed 15 feet.
Brokamp is one of the smaller varieties of English ivy, seldom exceeding a height of 5 feet. Slow growing and delicate, it is a good choice for small containers and window boxes. The tri-lobed leaves of Brokamp are less pointed than other varieties, lending them a vaguely heart-like shape. The leaves are dwarf and are less than 2 inches long with a uniformly dark-green colouring, sometimes with a pronounced light-green central vein. The stems of Brokamp are less flexible than other varieties and are susceptible to damage if moved excessively, so once planted it is best to avoid repotting.