Facing Climate Change: What Gardeners Need to Know

By Sharleen Pratt, Master Gardener

I recently attended a Master Gardener’s Technical Update at the Toronto Botanical Gardens. The subject was Facing Climate Change: What Gardeners Need to Know. The speakers were Dr. Jon Warland, Dr. Steven Hill and Lorraine Johnson. As we sat listening to how our climate is changing and the impacts that this has on current gardening practices, it was not lost to us that we were about to experience an upcoming ice storm at the same time that Australia was dealing with horrific fires. And then on January 17th, Newfoundland is hit with one of the worst winter storms they have ever had!

Some interesting facts I took away with me that day were:

Plants that were once borderline hardy are now easily surviving our winters.
Severe storm conditions are damaging many of our trees.
The Sugar Maple could disappear in this century from the Greenbelt area.
Invasive plants are taking hold and pushing out some of our woodland native plants.
The average concentration of CO2 in the atmosphere was about 250 parts per million (ppm) in pre-industrial times. Now it exceeds 400 parts per million (ppm).
The peak bloom date for cherry trees in Washington, D.C. has shifted earlier by approximately five days since 1921.
The current climate in the Golden Horseshoe area will be in Algonquin Park by the end of the century.

Lorraine Johnson spoke at great length about our perception of what was a ‘nice’ garden. She believes that we need to understand the benefits of growing native plants that will be hardy enough to withstand the unpredictable extremes in climate. She presented several examples of people who had replaced their front lawns with native plants or vegetables and had been instructed by the cities to remove the plants or had received bills when the city moved in and cut it all down only because it was considered ‘messy’ and ‘unappealing’!

What we can do as gardeners:

Consider using native plants. You will be rewarded with lots of birds, butterflies and insects to help cultivate a natural ecosystem.
Grow as many plants as possible (I won’t have a problem with this one). Gardening is a journey and learning what plants work best in your conditions takes time and patience.
Learn to live with some weeds, nibbles in leaves, as well as leaf spots. Focus on cultivating plant health.
Stop watering your lawns as it is estimated that nearly one-third of all residential water is lost in the watering of lawns. Your lawns will go dormant in dry periods but will return with the fall rains.
Consider a rain garden to minimize surface runoff.
Include a diverse mix of plants, shrubs and trees to prepare for the possibility of losing certain plants due to climate change.
Leave grass clippings on your lawn to add nutrients
Mulch fall leaves and add to your lawn or flower beds to avoid having leaves sent to the landfill where the organic material undergoes anaerobic (without oxygen) decomposition that produces the greenhouse gas methane with is worse than CO2.
Grow your own vegetables or buy locally from farmers markets to help reduce greenhouse gases when food travels thousands of kilometres from farm to grocery store.
MOST IMPORTANT … Get out in your gardens and be thankful for the beauty that surrounds you!