Those Ivied Walls

Just a little Gothic: Princeton

The “Ivy League” was originally a sports arrangement, existing unofficially in the 19th century, getting its name in the 1930s and finally coming into formal existence in 1954. The seven of the eight schools included – Dartmouth College, the University of Pennsylvania, Harvard, Brown, Yale , Columbia, Princeton, and Cornell universities – were founded during the Colonial period (Cornell as founded immediately after the American Civil War). Their campuses were indeed distinguished by buildings covered with ivy. There were even annual ceremonies during the 19th century during which ivy was planted next to the walls of academic buildings.

Although the Ivy League is technically a sports agreement, because it was made among the oldest, most prestigious schools in the country the term ‘Ivy League’ has always connoted social elitism and a high standard of academic excellence. At various times Fordham, Georgetown, Rutgers, Syracuse, the University of Pittsburgh, and even the U.S. Military Academy (West Point) and the naval academy (Annapolis) were grouped with what are now considered the canonical eight.

Apparently if a building was covered with ivy, it meant that it had been there for some time and that implies continuity, stability and, by virtue of these characteristics, quality. Perhaps letting ivy grow all over your infrastructure also suggested a certain indifference to worldly concerns.

Hedera helix, English ivy

The “real” ivies, the genus Hedera, are members of the ginseng family, Araliaceae, and they are widespread in Europe, Asia and the “Macaronesia” islands off the coast of Europe and North Africa. Hedera species are evergreen and will grow up any vertical surface was extending aerial roots that attach to the surface. Stone surfaces are actually slowly torn apart by the ivy and it isn’t really a very good maintenance plan to allow Hedera to grow on built structures.

Parthenocissus tricuspidata, Boston ivy

Landscape designers very much discourage the use of Hedera, and instead advocate planting of Parthenocissus species if one desires greenery on a wall, pergola, or arch. P. tricuspidata or Boston ivy is deciduous and attaches to surfaces with small circular pads at the end of tendrils. The pads are glued to the surface by calcium carbonate secreted by the plant. While this makes white deposits across the surface of the building stone or brick, it doesn’t not disintegrate it.

Although called Boston ivy for its ubiquity in that city P. tricuspidata is native to eastern Asia and is not a true ivy, but instead is related to grapes. Its leaves somewhat resemble those attached to grape vines, but they are three-lobed rather than five-lobed. Hedera helix (often called English ivy) has five leaflets on young shots, but has smooth, almost leathery five pointed leaves arranged alternately on mature stems.

Parthenocissus quinquefolia, Virginia creeper

The native Parthenocissus quinquefolia or Virginia creeper has five leaflets and is sometimes confused with poison ivy, which has three. The leaves of both vines turn a brilliant red in the fall before they drop. Like P. tricuspidata Virginia creeper attaches to surfaces with adhesive discs and doesn’t damage structures. Both vines, however, grow rapidly and may become too heavy to be supported by some trellises. Maintenance experts recommend killing the vines by cutting them off at the base. The carbonate on the discs will dissolve after the plant dies, making it easier to remove and preventing damage to the supporting surface.

Hedera gone wild in Maryland

All three of these vines produce berries that are consumed by birds, and this is their primary means of distribution. Hedera actually flowers very late in the autumn and into early winter. The small five-petaled flowers are borne at the end of stiff pedicels that radiate out in all directions from a central stem. The berries are greenish-black and poisonous to humans. Parthenocissus flowers are greenish, small and borne in clusters. Unlike Hedera, it flowers in the spring. The berries are small and bluish, betraying the genus’s relation to grapes.

Hedera is considered an invasive species where it grows in the United States. It is actually banned from the state of Oregon. Because it grows rapidly and is an evergreen, it tends to shade out all other plants, creating ‘ivy barrens.’ Even so, landscapers looking for a low-maintenance ground cover may plant it to fill a space and cut down on their weeding.


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