October 2020 in the Garden

For a self-guided tour, use Garden Explorer to locate plants featured in this month’s post. Select a tour in the drop-down menu.

This year more than most, we’ve hoped for each new month to bring us something better. I certainly can’t promise warmer weather, fewer COVID-19 cases or less societal unease for October, but for visitors to UBC Botanical Garden, I can promise cleaner, less smoky air, quiet and greater sense of contentment.

Most gardeners already know this, but there are plenty of studies that show that anxiety dissipates with time spent in nature and in gardens. In particular, having vegetation muffle sounds and trees block views to buildings, roads and other obvious constructions helps to take our minds off the hustle and bustle of urban life. Most of us relax and feel better in the presence of trees.

There are three areas in UBC Botanical Garden that can offer this kind of experience: the Carolinian Forest Garden, the BC Rainforest Garden and the David C. Lam Asian Garden. Regular visitors will know that each has a special feel all its own.

This month I thought I might invite visitors to have a look at our largest forested garden, the Asian Garden, from a slightly different perspective—that from the Greenheart TreeWalk. Visitors unsure about their comfort level on a moving, elevated walkway can certainly opt to stay on the ground (why replace one kind of anxiety with another?), but many people can get very comfortable, once they get the hang of the motion and the height. From the high vantage of the TreeWalk, the Garden unfolds as a carpet of verdant, not quite familiar shapes and patterns below.

Seen directly from above, the larger-leafed rhododendrons, native Polystichum munitum (western sword fern), sapling Thuja plicata (western red cedar), Tsuga heterophylla (western hemlock) and Abies grandis (grand fir) display a beautiful, unexpected symmetry. In this shaded forest setting, their radial phyllotaxy (phyllotaxy describes the spacing and arrangement of leaves around stems) tends to maximize light interception while reducing self-shading.

Other plants, including the native and ubiquitous Sambucus racemosa subsp. pubens var. arborescens (coastal red elderberry) and Corylus cornuta (beaked hazelnut) tend to fill all available space around them with their wide-spreading, but irregular branches and broad leaves. Phyllotactically-speaking, these latter subjects behave in a similar way to the exotic snake-bark maples that populate the area around the last three bridges and platforms of the Walkway. But whereas the hazelnuts and elderberries tend to remain below the TreeWalk, the maples produce slender, arching stems that rise elegantly to 10 or 15 m.

My favourite part of the TreeWalk is the first platform beyond the free-standing tower. From here, to the left and right you can see exotic maples from the mountains of southern China (Acer forrestii), northern Vietnam (A. pectinatum) and Taiwan (A. rubescens). The TreeWalk runs along an approximate east-west line at this point. Looking to the north and northeast are two relatively young, but rapidly growing Cercidiphyllum japonicum (katsura) trees. At this distance and elevation, their regular, sweeping branches, flawless outlines and ordered internal structure is revealed, and with a breeze from the appropriate direction, October visitors should be able to smell the burnt-sugar aroma of their yellowing leaves.

About 50 m to the north beyond the maples on the east side of Sargent Trail stands one of the most unusual trees in the Botanical Garden’s collection, Bretschneidera sinensis. This twenty-five-year-old specimen has a ramrod-straight stem and bears only a few short side branches, but massive compound leaves. In the wild, the showy, foxglove-like flowers of Bretschneidera are produced at the very tip of the trees when the stems eventually emerge from the surrounding vegetation. When our plant flowers, perhaps in another decade or so, the blooms will be best seen from the tower, as the tree has already surpassed the height of every other bridge and platform.

Whether you focus on specific plants in the collection, explore the exhilarating heights of the TreeWalk, or just want to tramp the comfortable pathways under the trees and breathe in the fresh air, a visit to the Botanical Garden will probably do you a world of good.

Submitted by: Douglas Justice, Associate Director, Horticulture and Collections