What to do, what to do?
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| Echinacea pallida |
Doug Tallamy, American
entomologist, ecologist and conservationist recommends that 70% of plants in a
garden should be native species as a food source for pollinating insects. It’s
become a popular talking point over the last few years, especially on social
media. It’s a worthwhile goal, and I encourage anyone to follow this advice
should they wish to do so.Much of the current concern
about pollinators took off after a report from Germany showed a drastic
reduction in insects there. This was picked up by the media and made for alarming
headlines — dramatic events are more publishable. Yet unlike Europe where almost
all land has been modified for human use, findings indicate that large-scale
insect declines across North America remain an open question. There are few
studies showing an overall decline, although this doesn’t mean there are not areas
where this has occurred.
This raises questions for me about
the situation in this area. Prior to a couple of hundred years ago, southern
Ontario was heavily forested, then the forests were felled to make way for farmland
and much of the natural landscape was lost. Urban growth followed, absorbing
swaths of that farmland, then in the decades following World War II, all manner
of pesticides became available. They were heavily used in agriculture, by
municipalities, and by homeowners.
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| Verbascum chaixii 'Wedding Candles' |
This was a time when green
lawns ruled and to ensure they stayed that way, they were sprayed heavily with weedkillers
— remember the tanker trucks that roamed neighbourhoods leaving a chemical
smell in the air? Thankfully, that ended in 2008 with the Ontario pesticide
act.
Prior to about thirty years
ago, other than grass, there might have been a small vegetable plot. out back
with room for a clothesline. In the front yard, most homes had only what was
termed a foundation planting out front, three or four evergreens and limited
selection of flowering plants. There were far fewer sources for plants compared
to now when big box and grocery stores have become garden centres. Filling the
front and back yard with rare and unusual plants would have been seen as
radical. This began to change largely due to the Communities in Bloom program starting
in 1998, which encouraged front yard plantings, and over the last twenty years interest
in growing flowering plants has surged.
Growing vegetables, too, has
become hugely popular. However, backyards are still largely a play area for
kids and pets, although many trees and shrubs have been added where none grew before.
People build gardens for many reasons, and in an urban environment it isn’t
easy to recreate a natural ecosystem where plants and insects have developed a complex
web of interrelationships, yet those who opted to plant flower gardens with a
wide range of plants have done much to support pollinators. Non-native plants
might not cater to all species of insects, but they can provide nectar rich
flowers for generalist feeders, and native birds and insects will happily feed
on both native and non-native plants. It’s the specialist feeders that are most
in need of specific plants that support them, like the monarch butterfly that
relies on milkweed. However, only a relatively small percentage of insects require specific plants, and each has co-evolved with a colony to suit their needs. A single plant in an urban garden may not be enough to meet their needs (see below).
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| Hoverfly |
Planting any kind of garden
is a positive thing when one considers what is being done to the planet,
especially so as climate change, pesticide use, and loss of greenbelt continue
to threaten pollinating insects on a much bigger scale than a simple garden that
has long provided habitat where non existed before. So yes, do avoid using
invasive, exotic plants, and certainly add more native species to attract
pollinators, even 70%, but don’t be afraid to grow what you love, providing it
causes no harm to the environment — know your plants, and your pollinators.
It is worth noting that in
the US, where the movement is strongest, pesticide use by home gardeners is
still permitted. Eighty-five types of pesticide outlawed in other countries are
still allowed there. Add a comment below.
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| NOT my garden |
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| My garden |