The Victoria Day weekend marks the beginning of the gardening season for many, with updated information available this year on suitable plant varieties for outdoor survival. According to John Pedlar, a research scientist at the Canadian Forest Service, the primary reason for this update is the changing climate. Recently, researchers revised Canada’s plant hardiness zone map for the first time in ten years, a tool utilized by both nurseries and casual gardeners to identify plants most likely to thrive in specific climates.
The map considers various factors like rainfall, winter temperatures, and wind conditions, providing a comprehensive view of plant survivability. Natural Resources Canada (NRCan) released the updated data last July. Plant hardiness zones represent areas with similar climate conditions, ranging from 0A to 9A, indicating the ability to support plant growth. The plant composition in these zones is generally similar due to the close relationship between plant survival and climate conditions.
While significant changes were observed in western Canada, regions like Almonte in eastern Ontario saw a full zone increase. Areas near Kemptville and Smiths Falls experienced a half-zone rise. This shift allows gardeners to potentially cultivate cherries, pears, and select apricot varieties that were previously not viable. Notably, Ottawa and Kingston maintained their position in Zone 5A.
At Robert Plante Greenhouses in east Ottawa, adjustments to inventory have been necessary to adapt to the evolving climate. Manager Colin Matassa mentioned the increasing variety of plant options suitable for the area. Staff at the greenhouse are knowledgeable about plant hardiness zones, and gardeners can easily identify suitable plants through information tags.
The May long weekend typically sees heightened activity at the greenhouse, with customers like Christine Dobson exploring plant selections for their yards. Dobson emphasized the importance of balancing aesthetics with climate compatibility in landscaping decisions. While the updated hardiness zones offer new possibilities for gardeners, they also reflect broader climate change trends. However, the changes do not imply an immediate shift to tropical crops like bananas in Ontario, as stated by John Pedlar.