In 2002, my daughter and I were on a bus trip to Manitoba. We were both relatively new to the perennial gardening scene, and were amazed at the diversity of plant material available in Manitoba nurseries, from trees to shrubs as well as perennials. One of the trees we came across at a Morden Nursery was the Catalpa tree; the Northern or Western Catalpa (Catalpa speciosa), which survives in sheltered microclimates in Manitoba.
Not to be scared away by a mere hardiness label, my daughter decided to order a tree and planted it on the boulevard in front of her tiny home in the Exhibition area. Many years later, she has since moved, but the tree still survives on the boulevard.
Northern Catalpa is native to a relatively small area where the Mississippi and Ohio rivers meet in western Kentucky and western Tennessee. It has been cultivated in Ohio for two hundred years, where it was used by farmers to make fence posts, furniture and trim boards in building. Northern Catalpa is now naturalized in the Midwestern United States. A fast-growing tree in its native range, it is much slower growing in the north. You can view the Catalpa in Patterson Gardens or in the boulevard on the corner of Hilliard Street and McPherson Avenue in Saskatoon.
The leaves come out in late spring and are still small and yellowish while many other trees have dark foliage. Leaves grow quite large on long stalks on opposite sides of twigs. Leaves can be 15cm in width (5 to 6 inches), are heart-shaped at the top but come down in a triangle to a very narrow pointy tip. The Catalpa flowers in July and has clusters of large bell-like white flowers with purple spots in the centre. The seed pods resemble narrow but very long beans which persist through winter, hence its other name ‘cigar tree’. In fall the leaves will yellow and drop off, or some years they will all fall to the ground after a hard frost. In northern climates like ours, it probably will only attain a height of around 15 metres, compared to its usual height of 30 metres.
Another oddity in the landscape at the Saskatoon Forestry Farm park is the white mulberry tree (Morus alba). Probably a leftover from the days when the Forestry Farm was the Sutherland Forest Nursery Station. This tree is quite small and is in a stand of trees between the wedding garden and the Kinsmen Playground; it faces the lawn. The white mulberry has varied leaves, some oval and smooth-edged and others lobed. The flowers are catkins in spring. Its edible fruit ranges from whitish to pink but turns almost black when ripe, resembling an elongated blackberry.
Native to China and India, it was cultivated to feed silkworms employed in the commercial production of silk. It was introduced to Canada in the 1800’s as a fruit tree and is now widely naturalized in warmer zones and a concern in regions like Ontario, where it is considered an invasive species and will outcompete the endangered red mulberry.
Another plant I have encountered at the Forestry Farm and have not seen elsewhere is Oregon Grape (Berberis aquifolium). This shrub is native to the Pacific Northwest from Oregon to British Columbia. It is a zone 5 plant which has been surviving at the Robin Smith Meditation Garden since it was opened around 1998. I do not know if it was planted then or was a holdover from the nursery days.
In its native habitat, Oregon grape will flower in spring with yellow clusters of flowers and will later in summer bear fruit clusters. At the Meditation Garden I have never seen it flower, nor bear fruit. It has beautiful shiny leaves resembling English holly. This year, with the copious rain, it has really flourished, but only as a ground cover, not really a shrub. The leaves are evergreen, sometimes getting a purplish sheen in winter.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.
