Renewal of the Espalier Fruit Tree Collection

By Richard Hallman, UBC Botanical Garden Pomologist in Residence

UBC Botanical Garden was established on the UBC campus in 1916. The Garden is now celebrating its 100th anniversary, but it wasn’t until the 1960s that the Garden moved to its current location on Southwest Marine Drive. The first of the espalier fruit tree collection was planted in the Food Garden in 1983. At the time, the collection included a number of apples and pears, two plums and a quince. Many new trees were added in the years that followed, including additional apples and pears as well as figs and peaches. The fruit trees in the collection were trained into a wide variety of two- and three-dimensional espalier forms and eventually the Garden became known as having one of the best espalier fruit tree collections in North America.

Espalier is the ancient horticultural practice of controlling the growth of woody plants to enhance both productivity and ornamental effect. Two dimensional espalier forms were originally grown flat against rock or masonry walls to take advantage of the warmer microclimate near the wall. This allowed for the production of high-quality fruit on plants that would normally need a warmer climate to be as productive. Both two- and three-dimensional espaliers are usually grown with some form of trellis to support the trees and aid tree training.

The majority of the espalier trees in the original Botanical Garden collection were apple trees—trees that unfortunately suffer from several fungal diseases in our wet west coast climate. Apples, as well as most other tree fruits, originate in parts of the world with low rainfall, where diseases are not as significant as they are here. In British Columbia and elsewhere, commercial production of tree fruits occurs primarily away from coastal areas.

Over the years the apple trees in the Food Garden developed perennial branch and trunk cankers from infections by apple anthracnose and European canker. These diseases are prevalent on the coast and are easily spread through pruning and water-splashed spores. In 2014, when the construction of the Taylor Plaza was in the planning stages, the decision was made to renew the espalier fruit tree collection. The first of the diseased trees were removed during the winter of 2015 in preparation for construction. The remainder of the apple trees were removed in the fall of 2015 to ensure they would not infect the new apple trees to be planted in the garden.

New apple cultivars more suitable for our wet climate will be planted in the Food Garden this fall for training to espalier forms. The renewed planting will include many new types of trees and shrubs, and most of them will be trained into espalier forms. The new plants will include European and Asian pears, European and Asian plums, figs, apricots, quinces, medlars, persimmons, walnuts, additional grape and blueberry cultivars, and currants.

Since plant disease (and our weather) is the impetus for the renewal of the espalier fruit tree collection, the renewal project includes the development and implementation of organic integrated pest management (IPM) programs for each of the fruit trees in the garden. This will hopefully prevent the need for a future tree renewal on this scale. These IPM programs will include plans for both diseases and pests and will be available for tree fruit gardeners at the UBC Botanical Garden Apple Festival on October 15 & 16. Have a look at the redevelopment of our fruit tree and shrub collection on your next visit to the Garden.

About Richard Hallman

As a pomologist (fruit tree expert), Richard Hallman brings essential knowledge and experience to UBC Botanical Garden. Join him July 30 for his Summer Fruit Tree Grafting Workshop!

Submitted by Tara Moreau, Associate Director, Sustainability and Community Programs, July 15, 2016