Founded in 1974, Oregon Tilth is a nonprofit organization that certifies farmers as well as landscape professionals nationwide. Oregon Tilth actively promotes a more sustainable approach to landscaping via the Organic Landcare program. Through examinations and extensive training, landscapers can become accredited as an Oregon Tilth Organic Landcare professional. Periodically, the Organic Landcare program offers Peer Learning Sessions to share knowledge and techniques among industry professionals. On July 22nd, Oregon Tilth presented an organic land care peer learning session on the campus of Lewis and Clark College. Suzie Spencer, arborist and ground steward for Lewis and Clark College, led a tour of the campus, highlighting unique landcare features along the way.
Organic Solution: Combatting Boxwood Blight
Lewis and Clark holds the unique distinction of having experienced only the second outbreak of Boxwood Blight in the state of Oregon. Unfortunately, the outbreak occurred in the heart of campus, in the garden bed directly in front of the Frank Manor House. Licensed applicators utilized Zerotol, a broad spectrum organic fungicide/bactericide consisting of mainly hydrogen dioxide, to combat the blight. This has proved very effective thus far and currently, the campus is entirely free of blight.
The knot garden in front of the Frank Manor House. Hydrangeas have replaced annuals for a lower maintenance, less water-intensive garden bed.
Organic Solution: Algal Growth in Water Features
There is a large reflecting pool just east of the Manor House, and there had been persistent algal growth issues in this pool, as well as in a smaller nearby fountain. Both bodies of water had to be repeatedly emptied and refilled to remove algae, an unsustainable approach to pond care. Suzie discovered an interesting solution. Currently, she is utilizing an innocuous organic black dye, which decreases the sunlight able to permeate the water and therefore instantly decreases the algal growth. Another added bonus of this simple fix is that the water is much more reflective after the addition of the dye. It is completely harmless to the aquatic flora and fauna present in both bodies of water.
Reflecting pool just east of the Frank Manor House.
Organic Solutions: Improving habitat and garden yields
The Lewis and Clark campus has had several beautiful rose gardens throughout the property. Deer in the area were equally impressed with these rose gardens, finding them especially tasty. The grounds stewards saw opportunity in the devastation and turned the former rose beds into thriving pollinator gardens. One of these pollinator gardens was installed near the student-run community garden to improve food crop pollination as well.
A pollinator garden that also encourages pollination of the nearby student-run community garden.
Beneficial Partnerships
Lewis and Clark College has recently joined forces with Tryon Creek State Park, Riverview Gardens, SOLV, and other organizations to remove the invasive species in the ravine on campus. Ivy, cherry trees, English holly, and clematis are the main culprits in this area. They were treated by certified public pesticide applicators using aquatic approved herbicides and the results are already impressive. While the campus is typically a pesticide free zone, an exception was made to treat this natural area. The staff hopes to integrate new plantings along with the invasive species and gradually remove the remaining noxious plants as the new native plantings mature.
The efforts being made on the Lewis and Clark campus to further improve sustainability and decrease the use of pesticides is impressive. Suzie was an excellent and informative tour guide of the organic managed landscapes throughout the incredibly lush, beautiful campus.
