Ivy is appreciated by some gardeners for its ability to cover quickly, reviled by others for its invasive tendencies. Spreads horizontally over the ground; also climbs on walls, fences, trellises. Sometimes a single planting does both: Wall ivy spreads to become a surrounding ground cover, or vice versa. Climbs almost any vertical surface by aerial rootletsa factor to consider in planting against surfaces that must be painted. A chain-link fence planted with ivy soon becomes a wall of foliage. As a ground cover, it holds the soil, discouraging erosion and slippage on slopes. Roots grow deep and fill soil densely; branches root as they grow, further knitting soil.
Thick, leathery leaves are usually lobed. Mature plants will eventually develop stiff branches that bear round clusters of small greenish flowers followed by black berries. These branches have unlobed leaves; cuttings taken from them will also have unlobed leaves and will produce shrubby rather than vining plants. Such shrubs taken from variegated Algerian ivy (H. algeriensis 'Gloire de Marengo') are known by the name ghost ivy. Plain green H. helix 'Arborescens' is another selection of this shrubby type.
Plant ivy in spring or fall. Standard spacing is 1122 ft. apart. Amend soil (to depth of 812 in. if possible) with organic matter such as ground bark or peat moss. Before planting, thoroughly moisten soil; also make sure transplants' roots are moist.
Most ivy ground covers should be trimmed around edges two or three times a year (use hedge shears or a sharp spade). Fence and wall plantings likewise need shearing or trimming two or three times a year. When ground cover builds up higher than you want, mow it with a rugged rotary power mower or cut it back with hedge shears. Do this in spring so ensuing growth will quickly cover bald look.
Many trees and shrubs can grow compatibly in ivy ground cover, but small, soft, or fragile plants will be smothered. Ivy ground covers can be a haven for slugs and snails and can also harbor rodents, especially if the ivy is never cut back.
H. algeriensis (H. canariensis). ALGERIAN IVY. Zones MS, LS, CS, TS: USDA 7-11. Shiny, rich green leaves 58 in. wide, with three to five shallow lobes. Leaves are more widely spaced along stems than those of H. helix. Coarse-looking plant; aggressive grower. 'Gloire de Marengo' ('Variegata') has dark leaves marbled with gray-green and irregularly margined in creamy white; it does not take extreme heat. 'Ravensholst' is vigorous, with dark green leaves sometimes tinged purple in winter.
H. colchica. PERSIAN IVY. Zones US, MS, LS, CS, TS; USDA 6-11. Oval to heart-shaped leaves are largest among all ivies: 37 in. wide, to 10 in. long. 'Dentata' has slightly toothed leaves; 'Dentata Variegata' is marbled with deep green, gray-green, and creamy white. 'Sulphur Heart' ('Paddy's Pride') has central gold variegation.
H. helix. ENGLISH IVY. Zones US, MS, LS, CS, TS; USDA 6-11. Not as vigorous as H. algeriensis, this ubiquitous species features three- to five-lobed leaves that are dull green with paler veins and reach 24 in. long and wide. Tremendous genetic variation has given rise to a dizzying assortment of foliage shapes, sizes, and colors. Ivy fanciers classify the hundreds of selections according to leaf shape, and also by type if unusual. Leaf-shape categories are bird's foot (leaves have long, prominent main lobe), curly (undulated, frilled, or curly leaves), fan (broad leaves with small lobes of roughly equal size), heart-shaped, and ivy (traditional five-lobed leaves). Plants are also grouped as miniature (very small leaves), variegated, or arborescent (shrublike plants with unlobed leaves propagated from mature ivies). Oddity types have unusual growth patterns, odd leaf forms, or both.
English ivies have many uses besides their usual role as ground covers. They are excellent in pots and hanging baskets, trained into intricate patterns on walls, or grown on wire frames to create topiaries. Arborescent forms make superb additions to foundation plantings and shade gardens. Some arborescent ivies are short and mounding, others more upright. All are drought tolerant and carefreegood substitutes for euonymus and cherry laurel (Prunus laurocerasus). Resistant to damage by deer. Recommended selections include the following.
'Baltica' (H. h. baltica). Ivy type. Dark green leaves with whitish veins. Very cold hardy.
'California'. Curly type. Dense grower with dark green leaves.
'California Fan'. Fan type. Broad, light green leaves with frilly edges. Perhaps the most beautiful fan ivy.
'Conglomerata'. Oddity type. Upright grower with stiff stems and closely set, curly dark green leaves.
'Deltoidea' (H. hibernica 'Deltoidea'). Heart-shaped type. Dark green leaves. Also known by the name sweetheart ivy.
'Fluffy Ruffles'. Curly type. Ruffly, nearly circular, medium green leaves resemble pompons.
'Glacier'. Ivy type, variegated. Leaves are patched in blue-green and gray-green and edged in white.
'Gold Dust'. Ivy type, variegated. Green leaves with bright gold specks and blotches.
'Goldheart' ('Oro di Bogliasco'). Heart-shaped type, variegated. Irregular gold splash in center of dark green leaf.
'Manda's Crested'. Curly type. Light green leaves with long, curly lobes.
'Needlepoint'. Bird's-foot type. Slim, graceful, medium green leaves. Very popular.
'Ritterkreuz'. Bird's-foot type. Dark green, five-lobed leaves with lighter midrib.
'Shamrock'. Bird's-foot type, miniature. Dark green leaves with lighter veins have three nearly round lobes, with the outer two overlapping the middle one. Named for the Shamrock Hotel in Houston.
'Spetchley' ('Gnome'). Bird's-foot type, miniature. Leaves are only 1412 in. long, turn from dark green to bronze-purple in winter.
'Thorndale' ('Sub-Zero'). Ivy type. Large, dark green leaves with veins that turn light green to white in winter. Very cold hardy.