In Defense of Natives

High Park in Toronto is about 400 acres and features some important, rare habitat for native plants.

It was originally purchased by a man named John Howard, who deeded it to the city in 1873 on the condition that it remain a park. The city maintains it and preserves about a third of it in it's original -and rare - black oak savannah.

They do this through prescribed burns - which is remarkable for a property in the middle of the city.

The park staff who gave us a tour as part of the Toronto Garden Blogger's Fling showed us several sites that they are working on to beat back the invasive species that threaten to swallow this property and highlighted some amazing, now rare, ecosystems.

One of them is the blue lupine.  They knew that had a few patches of lupines, but it was only when they started the  burns that the flower sprang back and is now spreading again.  To me this highlights the role of legumes in the natural environment.  They are the marines of the plant world.  It's their job to establish a base, fix nitrogen from the sky into the soil, and make the area more habitable for other plants like grasses.

Like the bluebonnets of Texas, specialized insects evolved around this plant.  The Karner Blue Butterfly (Lycaeides melissa samuelis) is endangered in both Canada and the United States and is listed as extirpated by the Canadian federal Species at Risk Act (SARA). This means the species no longer exists in the wild in Canada, but can be found elsewhere. With the decline of the lupine, the host plant for the butterfly larvae, so goes the population of the butterfly.  There is a movement afoot to try to reintroduce the butterfly into the park now that these lupines are making a small comeback.

We were also reminded of another butterfly that is struggling for habitat - the Monarch.  The oak savannah supports milkweed, the majority of the plants are Asclepias tuberose as seen here. Interesting side note, one of the invasive species that they are trying to control is called "Dog Strangling Vine".  According to the Rare Plants of the Endangered High Park Black Oak Savannah Guidebook, it is also a type of milkweed.  Unfortunately for the Monarch, while they may lay eggs on it, their larvae don't survive.  The proliferation of this weed is cited as another reason that the Monarch is in decline.

I was very inspired by my visit here and it serves as another reminder that innocuous (to us) activities like gardening can have a devastating impact on the natural environment.  It's not just the chemicals we use, but our choice in plants that escape our control.  The Toronto parks people pointed us to a stand of Norway Maple that has taken over part of the park.  It's used as an ornamental - often  planted as a street tree - and spreads easily by seed.  I'm reminded of the dreaded Ligustrum that plagues Central Texas in the same way.

I like to consider myself a good soldier in the war for natives.  The best that any of us can do is try to live where we are.  Stay educated and diligent, try to be stewards not conquerers.  Find ways to use natives and not just fall for a pretty face that will turn into an ugly problem later.  And when you see a problem, jump in and take care of it.  Whether it be killing ivy, bamboo, bastard cabbage, ligustrum, or even maple trees, it's worth the fight and something each of us can do.  Plus, I'm telling you, pulling weeds and clearing brush is very meditative and satisfying.  So what's good for the soul can also be good for the natural environment.  A win-win!