UW Students Battle Invasive Ivy in Yesler Swamp
By Klara L. Hulick, ESRM ‘27
Yesler Swamp’s boardwalk on a gray fall day (Image Credit: Klara Hulick).
Past Husky Stadium, tucked within the Union Bay Natural Area lies Yesler Swamp. Despite its marshy name, Yesler offers a lovely forested oasis for the public. With a short, pleasant boardwalk that weaves through a soothing tree-lined area and past an overlook of Union Bay, it’s easy to fall in love with Yesler. Although Yesler Swamp has a pleasant appearance, it suffers from a hidden scourge: several invasive plant species, including English ivy, holly, and Himalayan blackberry have taken over the brush. These plants cause significant damage to Yesler Swamp’s native species by outcompeting them and suppressing the growth of tree and shrub species.
A blanket of English ivy growing near UW’s West Campus in November 2024 (Image Credit: Klara Hulick).
Fortunately, the UW chapter of the Society for Ecological Restoration (SER-UW) has organized weekly work parties since 2017 to help counter these invasive plants. The first two SER-UW work parties I attended focused primarily on the removal of English ivy, a noxious weed. Kirsten, a Yesler Swamp site leader for SER-UW, noted that their efforts have been successful as ivy has been pushed back from Yesler’s entrance since spring 2022 and that Yesler Swamp still has many native plants. Though, Kirsten admits that there is still more work to be done, as many of Yesler’s trees are still covered in ivy.
During my first SER-UW work party, I focused on removing ivy from a clearing near the beginning of the boardwalk. We pulled the younger ivy out of the ground and pried the smallest vines off of tree trunks. The roots were often longer than they looked, and overenthusiastic yanks sometimes sent dirt and slugs flying. Despite these minor setbacks, we managed to remove a fair amount of ivy, thorny blackberries, and spiky-leaved holly. However, complete eradication may not be possible until we can plant new native plants to discourage the ivy’s return.
The first site in Yesler Swamp I volunteered at, now with a sign from SER-UW (Image Credit: Klara Hulick).
The following week, we split into groups to tackle spaces off the boardwalk. My partner and I spent our time trampling a small patch of ivy while trying to clip vines as they snaked their way into the tree canopy. This ivy was more established than that of the first week’s clearing, with some vines measuring longer than six feet, which made them surprisingly good jump ropes. Together, the work party volunteers removed several wheelbarrows full of invasive plants that will be used as compost to support UW farming.
Though SER-UW has made significant progress, there is still work to be done to combat the scourge of Yesler Swamp. If you are a UW student interested in getting involved with SER, meetings at Yesler Swamp occur every other Sunday from 12 p.m. to 2:00 p.m.