Vines climbing Yale Art School in 1914

Plants: Ivy League

Yale is one of the elite colleges known as the Ivy League [1]. It was planted in New Haven, Connecticut in 1701. Some prestigious colleges like MIT and Stanford follow similar standards, but they are not official members of the Ivy League. It looks “old and venerable” to have brick and brownstone covered with permanent or seasonal vines. Those vines, at Yale at least, are not actually ivy, but Virginia Creeper. And what is it, exactly, about those creepy vines, ivy or otherwise, slithering up all the tower walls, that makes these schools so special? The vines appear to be holding up those walls. Instead, behind the tentacles, they are tearing these scholarly places apart. Ivy, creepers, wisteria, and honeysuckle are some of the most destructive plant invaders on earth. These vines have moved beyond the cities and have slowly taken over the greater landscape.[2] More slow growing and subtle than kudzu, Ivy is tearing our universities apart and suffocating our trees.

Focusing this Plant Post on English Ivy (Hedera helix) in particular, it is a frustrating, silent forest-killer.

Virginia Creeper takes over the walls and roof

Ivy Day

At Yale graduations the Classics students, who study Latin and Greek, jokingly celebrate “Ivy Day” with a witty poem they crafted for the occasion. Translating it for their fellow graduating seniors, the poem lyrically honored the admission date for the incoming freshmen and marked the spot where they were planting the vines. The spot that the seniors in my undergraduate class chose for the ivy was inside the Old Campus walls. The poem was an incantation for the vines to scale the spires of Battell Chapel. It cheered the Ivy to grow steadily, to destabilize the mortar and to hurry the tumbling down of those hallowed walls.

It turns out that steady growing ground cover, like English Ivy, can be a relentless and pernicious vine in the forests, as well as the cities and venerable schools of the Northeast.

Battell Chapel on the corner of College and Elm Streets in New Haven (circa 1911)

Hedera helix and other vines

Many gardeners in the Pacific Northwest brought ivy with them as an ever-green ornamental accent for their porch planters. Residents soon covered their local woods with the ivy. It looked so fresh and green all year long. Twenty years ago our yard in NE Portland was smothered under beds of English Ivy and St. John’s Wort, another “pretty invasive.” The former owners hated gardening, so they watered this ground cover for many years. It took us five seasons to get rid our yard of the two stubborn inhabitants. With eradication, soil treatment and aggressive native planting, we eventually returned our garden to a “natural state.”

Ivy Down and Up

Peter Wohlleben, in his book, The Hidden Live of Trees, explains it this way:

There are some plants that can make it up into the canopy. It’s particularly arduous and tedious to start right from the bottom. Ivy is one plant that does this. Ivy begins as a small seed at the foot of a tree with an open growth habit – those species that are particularly wasteful with sunbeams and allow any number of them to fall to the forest floor unused. Under pines or oaks, that’s enough for a nice thick, carpet of ivy to grow – at first, just on the forest floor. Then, one day, a tendril starts to climb up a trunk.[3]

Hedera helix, image by dream

It is that relentless, quiet climb that becomes so remarkable and destructive.

Wohlleben goes on:

Ivy is the only plant in Central Europe that uses small above-ground roots to anchor itself firmly to bark. Over the course of many decades, the ivy keeps climbing upward until it finally reaches the crown. It can live many hundreds of years up here, though ivy that old is more often found on rocky cliffs or castle walls. Some of the European literature suggests that ivy doesn’t hurt the trees it grows on. After observing the trees ground around our house, I can’t support this view. Quite the opposite, in fact. Pines need a lot of light for their needles, and they particularly resent this competitor taking over in the treetops. Branches begin to die and this can weaken trees so much that they give up. Ivy vines encircling trunks can grow as thick as small trees, and like boa constrictors winding themselves around their victims, they can squeeze the life out of pines and oaks. [4]

This process of snake-like strangulation is happening, just as Wohlleben predicted, all over the Pacific Northwest. Our neighborhoods, forests and parks in Portland are rife with these destructive, silent, green killers. There vines have grown as thick as Donald Trump’s forearms and they are climbing with tenacity and vigor up from the forest floors.

Cutting the ivy is hard work

“No Ivy League”

We have some intrepid conservationists in Portland, who regularly have herds of goats and sheep that systematically graze on the ivy to munch it from our forests. These environmentalists are part of the “No Ivy League,” [5] founded in 1994 to save Forest Park, Portland. The group has been on the warpath for years, but it is losing the battle. Having spent more than my share of back-breaking hours ridding our yard of Ivy, it is a thankless task. It may not be strangling our trees anymore, but our neighbors are not as diligent and it is gradually, insidiously getting worse.

One of several setbacks to the “No Ivy League” movement is that many urban residents feel that ivy is so pretty and natural and green and all. They are either newcomers or have poor memories. The English Ivy has replaced the native Salal, Trillium, Maiden Hair Ferns, Oregon Grape, Solomon’s Seal and other beautiful understory. There are few visible signs of the “No Ivy League” success. We seem to have more banned invasive plants, such as butterfly bush and English Ivy, than ever.

The Ivy League, collegiately and scenically, is here to stay … unless, that is, the regret about strangled trees takes hold. Otherwise, we may have long term destruction of our forest floors and canopy. Boola, Boola.

Maiden Hair Fern and natural NW understory


[1] Most American students are aware of the Ivy League. They may not know it is an athletic conference that agrees to follow the same scholarship and admission guidelines, with a de-emphasis on athletic scholarships without strong academic achievement and intellectual promise. An Ivy League university is one of the eight schools that make up the Ivy League Athletic Conference. The universities in the League are Harvard, Princeton, Yale, Dartmouth, Cornell, Columbia, University of Pennsylvania, and Brown.

The league pledges to be academically rigorous, with programs and facilities that are among the most sophisticated in the world. In addition to being among the most competitive schools, the Ivy League colleges are also among the oldest schools in the U.S. Harvard and Yale, for example, were founded before the U.S. formally existed. They are located in Cambridge, MA and New Haven, CT respectively. Only the top students from secondary schools around the globe are admitted to the Ivy League each year. Thousands of students apply, making it so that less than 10% of applicants find a spot in the Ivies each year.

[2] Here is an article from 2009 talking about the evils of Ivy and the war against it at Yale. https://yaledailynews.com/blog/2009/10/02/yale-fights-the-war-on-ivy/

[3] Wohlleben, Peter, The Hidden Life of TREES: What They Feel, How They Communicate, translated from German by Billinghurst, Jane, Random House, Canada 2015. p. 164.

[4] Ibid, p. 165.

[5] The “No Ivy League” in Portland was founded in 1994 by the late Sandy Diedrich. The organization is still around, but it’s effectiveness is waning, pushed to the margins. It is evident that other matters, like Black Lives Matter and Police brutality and racial equity and Covid-19 have become more urgent and pressing. https://www.oregonlive.com/business/2010/02/oregon_bans_sale_of_english_iv.html