As spring shifts to summer, the UC Berkeley campus is awash in flowers blooming, creeks bubbling slowly but steadily and deciduous trees with full leaf cover, such as the famous row of London plane trees lining the path to the Campanile. Unfortunately, this season also means that one of Berkeley’s unwelcome guests — Algerian ivy, or Hedera algeriensis — continues its rapid growth across the campus’s varied habitats.
It is not known when Algerian ivy first came to UC Berkeley, but its presence is now felt from Oxford Street to Piedmont Avenue. Indeed, the list of buildings with this invasive plant growing around it includes Barrows Hall, Doe Library, Evans Hall, the Faculty Club, Gilman Hall, the Hargrove Music Library, Haviland Hall, the Hearst Memorial Mining Building, Hertz Hall, Kroeber, the Life Sciences Addition, McCone Hall, Moffitt Library, Morrison Hall, Sproul Hall, Stephens Hall and Wurster Hall. While the ivy can be lovely as an ornament when it grows across walls, its proliferation here is far more damaging than is worth the aesthetic.
Like other invasive species, the problem with ivy at UC Berkeley is that it quickly throws off the balance of native plants and comes to dominate the landscape. Large parts of Strawberry Creek are covered in it — from the tops of its banks to the very base of the creek flow — including the area just north of the Faculty Club. Sadly, in those sections, the ivy seems to have killed nearly every low-lying plant in its path — from flowers to ferns to new tree saplings — and begun its climb up our stately redwoods, pines and eucalyptuses.
UC Berkeley’s mature trees are among the university’s greatest legacies and daily gifts to students, staff, faculty and visitors. But decades-old groves are threatened by this pest. Beyond applying pressure to tree trunks and inhibiting growth, ivy can also deprive tree roots and the rest of the understory of much-needed rainwater. The UC Berkeley campus is not unique in this regard; Hedera grows exceptionally well in shaded, moist places, and it has found its way into the Redwood National and State Parks in far Northern California. It poses such a scourge to western forests generally that Washington and Oregon prohibit the sale of many types of ivy, and there are calls for California to do the same.
While the problem is widespread, the solution is straightforward: weeding. As imposing as a bed of ivy seems from a glance, it can be pulled by hand, and its vines can be clipped from tree trunks with a pair of garden shears. A peer-reviewed article was even published specifically on ivy removal at UC Berkeley, indicating that manual removal was effective and would have the fewest negative effects on overall biodiversity. While the Creeks of UC Berkeley organization has done exemplary work in removing ivy and replanting native species, notably behind the Women’s Faculty Club, there is far too much ivy for just volunteers to manage. In addition to volunteer efforts, UC Berkeley must dedicate significant new funds to eradicating ivy from the campus and replanting before more habitats or canopies are degraded.
Specifically, budgetary increases to grounds services should be earmarked for training staff to identify invasive plants, which is difficult on a campus such as UC Berkeley with such a wide number of different habitats. In addition, time in their busy schedules should be allotted for ivy removal and restoration of the forest floor. This is not only to protect our existing stands of trees but to promote the growth of the next generation of trees that currently are choked off.
It is highly understandable that UC Berkeley’s landscapers focus their time on the necessities of campus upkeep such as mowing lawns, clearing paths, watering and removing dangerous tree limbs. But it is also important to augment the budget so that the campus staff has time to deal with ivy. This type of investment is far cheaper than reckoning with the damage caused by inaction, which includes weakened and damaged trees going forward.
In addition, there is no reason the campus cannot be more creative in dealing with ivy; many properties and local governments have turned to rentable herds of goats to deal with invasive plants, including the Presidio of San Francisco. This may not work in areas along Strawberry Creek, which are sensitive to erosion, but goats likely would work well where ivy has run rampant alongside buildings and across open space. The lawn between McCone Hall and the East Asian Library is an ideal candidate for that approach; goats could be fenced into that area, and — under supervision — be allowed to eat away at the proliferating layer of ivy.
Finally, with a warming climate, trees are the cheapest and most efficient way to sequester carbon, produce oxygen, clean the air, lessen flood runoff and cool the ground below. Ivy threatens this possibility, and we can make strategic investments to control that today. Even if Chancellor Carol Christ does see the value of removing ivy from UC Berkeley, perhaps she could expedite this request; after all, University House — her ceremonial home — is also full of ivy, which runs amok in the adjacent creekbed and up the trunks of her personal redwood grove.