“We’re on the right track.”
– CLAUDIO STASOLLA, PLANT SCIENCE PROFESSOR, UNIVERSITY OF MANITOBA
The tree producing Canada’s emblematic red maple leaf may one day find a home on not-so native land: Manitoba
The natural range of the sugar maple, with its glorious fall colours and prolific volumes of spring sap, now extends only to the eastern edge of the Prairies. Timing of spring frosts in Western Canada prevents viable seed development.
But some sugar maples, once established, do survive, as seen in Winnipeg and along some boulevards in Morden and Portage la Prairie.
But these are trees that have been grown from a planted seedling. Currently, Manitoba nurseries propagate sugar maple only by bud grafting, a labour-intensive process that requires the root of another plant, which may not be adapted to Manitoba conditions.
Now a University of Manitoba research project, funded through the Agri-Food Research and Development Initiative (ARDI), may have found another way to produce sugar maples for Manitoba: propagation via rooting from stem cuttings.
Last July, researchers collected stem cuttings from a cold-hardy sugar maple cultivar called Unity at Jeffries Nurseries in Portage la Prairie. The cuttings were brought to Shannon Oaks Tree Farm at Morden, treated with rooting hormones and planted in a soil mix.
The experiments were successful. The researchers report as high as 90 per cent rooting results in some instances. For commercial viability 80 per cent is considered satisfactory.
“We’re on the right track,” said Claudio Stasolla, a plant science professor at the University of Manitoba who worked with master’s student Teresa Sutanto on the project.
“Definitely, this project demonstrated that propagation is possible.”
But there’s still more work ahead before this can move ahead into production, notes Sutanto, who is conducting the research in partial fulfilment of her master’s degree.
“There are numerous factors that come into play to achieve high rooting success,” she said. “What we found this year proves great potential for sugar maple propagation for Manitoba’s nursery industry. However, the factors need to be optimized for more consistent results.”
Some of the work ahead lies with finding out how regionally adapted these trees will be to this climate, says Shannon Oaks Tree Farm owner Dave Klassen, who supplied the facilities and controlled environmental conditions during the experiments with cuttings.
“The next step would be the transition of taking this rooted cutting and growing it on and producing a quality larger plant that would be suitable for going into the landscape,” Klassen said.
The stem cuttings collected at Jeffries last summer are from trees a third generation off original seed collected from Minnesota and grown out during research at the Morden Research Station.
Sugar maple trees from this research are those standing on street boulevards in Morden today.
Researchers at Jeffries have been testing and evaluating the Unity cultivar, created by taking material off these Morden parent trees and bud grafting it on to seedling stock.
But the problem with budded plants, aside from how labour intensive they are to produce, is that they have roots which are not genetically identical to the rest of the tree.
That raises questions about how cold hardy these trees may actually be, says Philip Ronald, who oversees plant research and development at Jeffries.
Now, with these “own-rooted” cuttings available through this project, they’ll be able to compare these against budded plants and note any differences in survivability, Ronald said.
Further experiments may also show differences in the rate of fall colouration, he said.
“A plant’s response to the onset of winter can be impacted by the root system.”
The project aims to diversify the number of shade trees available in Manitoba, beyond the standard elm, ash and oak. Without this diversity, a single disease or pest may threaten whole stands of trees, as seen with Dutch elm disease and the emerald ash borer.
The sugar maple is a stunningly beautiful tree, producing brilliant fall foliage that can range from yellow to orange to red, depending on weather conditions. Sugar maples grow as tall as 40 to 50 feet.
The project received support from Shannon Oaks Tree Farm, Jeffries Nurseries, and Glenlea Greenhouses as well as through the $66,000 ARDI grant.