Halifax to test resilience of palm trees in 'pretty harsh' winter climate
Keith Doucette, The Canadian Press
Published Wednesday, August 1, 2018 12:01PM EDT
Last Updated Wednesday, August 1, 2018 4:55PM EDT
HALIFAX -- Atlantic Canada's largest city has a new, and highly unlikely, tropical flavour.
Nine palm trees have been planted in four Halifax parks, although the jury is out on whether they can survive winter in a North Atlantic city known as the Warden of the North.
The parks, all on the Dartmouth side of Halifax Harbour, now feature cold-hardy palm varieties that can grow in more northerly climates of Asia like China and Japan, or from areas of the continent with high altitudes such as northern India.
The varieties include windmill and miniature Chusan palm, which are native to parts of Asia; needle palm, which is found in the southern U.S. states like Florida; and pindo palm, native to South America.
Municipal horticulturalist Chris Poole said aside from wanting to see if the palms can survive, it's also part of his job to create public interest and to encourage people to enjoy the city's public spaces.
"I think by planting these palms around we've certainly achieved that and more," said Poole, who noted windmill palms as a tall variety that look like a typical palm tree.
"They are certainly the ones that are creating the most buzz because when you take one look at them it just looks as if you are in a different part of the world," he said.
Palms are grown elsewhere in certain parts of Canada, most successfully in Vancouver -- one of the warmest of the country's big cities during winter.
By contrast, the minimum daily temperature in Dartmouth averages minus 8 degrees Celsius in January and February, according to data from Environment Canada. And temperatures can dip well below that during typical cold snaps.
Ben Freeman, a post-doctoral researcher at the University of British Columbia's Biodiversity Research Centre, is skeptical of Halifax's palm plan although he "applauds the ambition."
He said the trees' keys to survival in more northerly climates are cold and frost tolerance.
"Unless you actually go and try you don't know whether they will survive, but I'm guessing that Halifax is too big a jump right now with current climates for palms," Freeman said.
Still, Freeman thinks Halifax's experiment is "pretty interesting," because climate change has made colder places a little bit warmer.
"It really is true that you can plant palm trees a little bit further north than you used to be able to 50 years ago," he said. "But I don't have high hopes for the long-term survival of palm trees in Halifax."
Egan Davis, lead instructor of horticulture training at UBC Botanical Garden in Vancouver, said he sees the windmill palm as the only species with a chance of surviving a winter climate like Halifax.
"Halifax has a pretty harsh climate even though technically the lows are not as cold as in other places where you can grow palms," said Davis. "It's just the harshness there, the storms and the amount of snow and the wetness over the winter."
Poole acknowledges that cities such as Vancouver are in a "whole different climate zone," but he points out that palm trees have been grown in different parts of Ontario.
"They (palms) are certainly being planted in some challenging areas and with a lot of success so we are hoping to do the same," said Poole.
The supplier of Halifax's trees is a Montreal-based company.
Sam Austin, a Dartmouth councillor, said he has received a lot of positive public feedback about the palms.
"We've got a long tradition of showing off species that aren't native as part of our parks program," said Austin. "Not everyone has the chance to travel and now they can come see a palm tree without necessarily flying several thousand kilometres."
Halifax has planted exotic species with various degrees of success in the past, including coffee and pineapple.
Most recently, an agave bloomed last month in the city's renowned Public Gardens. The plant had spent most of its life in the city greenhouse before being transplanted outside this spring, drawing curious crowds.
Poole said the palm trees will likely require protective measures this winter. Those include mulching around the base of the trees to protect roots, wrapping the trunks, and tying the leaves into a tight mass to keep the crowns dry.
Poole said the needle palm can withstand temperatures in the minus 18 to 23 range, while the windmill palms may need some kind of structure around them to protect from wind and severe temperature fluctuations.
However, the pindo palms will likely need to be housed in the greenhouse for the winter, Poole said.
If the experiment proves to be a success, Poole said there will likely be more palms doting Halifax's landscape.
"I don't think you are going to see them planted en masse by any means, but to have a focal point here and there in our park systems I think is the goal," he said.