Plant Blindness

TORONTO, ON - SEPTEMBER, 20 Mark and Ben (his son) Cullen are seen in the Star studio for logo photos. The two will be co-writing the weekly Urban Growth column in Homes & Condos. September, 20 2017

By Mark and Ben Cullen

Anyone would be impressed. Standing in front of the skeleton of a Blue whale has a jaw-dropping effect. It is hard to imagine a mammal THAT big. We were at the Royal Ontario Museum, enjoying a special birthday treat with family, which is about as rare as a Blue whale sighting.

At 25 meters (80 ft.) long and 150 tonnes, a Blue whale is hard to beat for bigness.

Unless you are looking at a 350 year old white oak, like the one that grows in a residential back yard in Etobicoke.  Believed to be the oldest tree in Toronto, this Methuselah of trees could tell a lot of stories about our history, if only it could talk. Heritage designation had been applied for on behalf of this behemoth, over 10 years ago. As of today, it still has not been granted.

The point is: we will go to enormous lengths to preserve a whale, take it apart and display it in a museum, but we have trouble noticing the importance of a tree that is more than twice the size and almost 10 times the age of a whale.

Botanists now have a term for this: plant blindness.

In 1998, researchers James Wandersee and Elisabeth Schussler introduced the term ‘plant blindness’. The research showed that when people looked at pictures of different landscapes, most would notice the animals and other objects before plants. Tony DiGiovanni, Executive Director of Landscape Ontario, responds to these findings with this, “Something that is unappreciated and unnoticed has little value.” And he is determined to fix that.

Landscape Ontario is a founding member of Green Infrastructure Ontario Coalition, an organisation that represents the interests the ‘natural vegetative systems and green technologies that collectively provide society with a multitude of economic, environmental and social benefits, including urban forests, bio swales, engineered and natural wetlands, ravines, meadows, agricultural lands and more.’

Economic Powerhouse

The Green Infrastructure Ontario Coalition provides some important numbers:

  • The ‘green’ sector employs 140,000 in the private sector in Canada (for comparison, Chrysler Canada employs about 10,000).
  • Including the public sector, over 280,000 people are employed in the green sector.
  • Consumers spent about $11.7 billion on landscaping and horticultural products last year.
  • The farm gate value of horticultural trees, shrubs and other plants grown on Canadian farms is over $2 billion.

Green Infrastructure provides a lot of Canadian jobs and is a powerful economic engine.

As DiGiovanni says, “It is the job of our profession to tell our story of benefits in ways that will be heard”.

Here is the buzz.

Last spring, on Mother’s day, our family gathered at our house for a celebration. We asked our two son-in-law’s Rene and Martin to come to the backyard. We walked them quietly down to a 10-meter-high pussy willow and stopped under it, asking for silence. “WHAT IS that?” they both exclaimed in a loud whisper. We pointed up into the branches of the willow where thousands of honey bees were busy harvesting an abundance of nectar and pollen. The buzz was deafening.

From that day on, our pussy willow is looked up to differently by those two. More accurately, it will be looked upon, finally! A large flowering shrub among many others in our 10 acre garden, this tree was easy to overlook until the bees discovered it. And we discovered the bees.

Curing Plant Blindness

Perhaps, there is the rub:  when we find wildlife that engages with the green world around us, we notice the green living world that supports it.

The benefits of green infrastructure are many. Here are just a few:

  • Lower up-front construction costs for the same level as ‘grey’ infrastructure.
  • Green infrastructure often reduces maintenance costs of other infrastructure and expands the lifespans. The shade and cooling effects of mature street trees, for example, significantly extend the life of asphalt roads and concrete sidewalks under their canopy.
  • Green infrastructure can prevent large-scale damage and reduce costs of floods (this should be of interest to insurance companies and municipalities alike).

If only we could see the oxygen that we inhale, manufactured exclusively by the green, living plants around us.

If only we could put a value on the toxins that are filtered by lawns and tree roots from rain water.

If only we could pick the fresh fruit from all the trees in our yard. 

Perhaps then, we would not be so blind.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and holds the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at, @markcullengardening, on Facebook and bi-weekly on Global TV’s National Morning Show.