PLOT 1 PLANT LIST
Hibiscus syriacus H2013-017-05 Philadelphus madrensis hybrid
Rosa Petite Knockout ®
Hibiscus Purple Pillar ® Vitex agnus-castus Blue Diddley ®
Philadelphus ‘ Blizzard ’
Ceanothus ‘ Victoria ’ Mahonia aquifolium
Hibiscus Pink Chiffon ®
Hydrangea ‘ Pee Wee ’
Lagerstroemia Center Stage ® Red
Osmanthus ‘ Variegatus ’
Rosmarinus ‘ Arp ’
Rosa Oso Easy ® Double Pink
Rosa Oso Easy ® Urban Legend ®
Plants were installed based upon a plot randomization grid created by Hsu . “ That ’ s the Holy Grail ,” says Zuckerman admiringly of the brightly colored grid with 360 blocks , each representing a plant . “ If we didn ’ t have that we wouldn ’ t have gotten anywhere .” ( Randomization helps remove potential bias or error that may crop up due to slight environmental variations at the site , e . g . one area receiving slightly more sunlight than another .)
The installation took place a week before the infamous “ heat dome ” hovered above Seattle , creating record temperatures and unfortunate leaf scorch in the region . Of course , the team paid attention to the forecast and delivered extra irrigation in advance to mitigate the heat ’ s impact . There were only nine casualties . “ We had to replace six Philadelphus , plus one Hydrangea ‘ Pee Wee ’, one Rosa Oso Easy ® Double Pink , and one Rosmarinus ‘ Arp ’. So only nine out of 360 — not bad ,” Kim remarks .
Passersby are definitely curious about the plot . “ There has been huge interest ,” says Zuckerman . “ There have been a lot of people walking by the plot when we ’ re working there and they want to know what ’ s going on .” Stuke agrees : “ It ’ s been fun to describe the design and objectives to the public and receive positive feedback . It ’ s exciting for regular users of CUH to be able to see the research occur in real time . They ’ ll be able to watch the plants grow and possibly even see the treatment effects when they start to show up next year .”
What ’ s Next During next year ’ s treatment season there will be three open houses . “ We ’ ll invite horticultural professionals and university extension Master Gardeners to view and evaluate the performance of selected plant material ,” Kim says .
In fall 2022 , data collected on Plot 1 will be analyzed and communicated to the green industry , horticultural community , and other researchers so that all can incorporate learnings about water-wise plants into their production plans .
Bilotta has begun soil preparation on a second trial plot ( Plot 2 ) next to the UW Farm at CUH , which will be configured slightly differently than Plot 1 in its plant selection , soil characteristics and physical dimensions . With Larson ’ s advice , the team is finalizing the plant list , which currently includes species of Lantana , Galtonia , Cercis , Azalea , and Physocarpus , as well as Caryopteris × clandonensis .
Jessica Farmer , adult education supervisor at UWBG , is keen to create educational programming related to the project ’ s insights . “ With climate change so top-of-mind , especially after this summer ’ s heat dome , people are really becoming interested in learning about how to garden with plants more tolerant of heat and drought conditions . These plant trials couldn ’ t have started at a better time .” m
Reprinted with permission from the UW Botanic Gardens blog , botanicgardens . uw . edu / about / blog .
Clare McLean was the communications intern at the University of Washington Botanic Gardens during summer 2021 . She is a birder , writer , photographer , plant lover and fungi hunter who is studying horticulture and sustainable land management at Edmonds College .
Fall 2021 v 13