Are You Choosing the Right Flowers to Save the Bees?
Tri-Coloured Bumblebee / Orange-Belted Bumblebee
Across the country, there has been a surging interest in saving the bees. A wave of bee-friendly action is taking root, with people stepping up to invest in pollinator gardens and cutting back on pesticide use. But to answer whether we’ve been choosing the right plants to save the bees, we’ll have to start with another question: which bees?
Honeybees vs. Native Bees
When people think of saving the bees, they tend to bring honeybees to mind. These are the most commonly depicted bees in our films, tv shows, and children’s stories. Because of this, you might be surprised to learn that honeybees are not native to North America! And while the treatment and health of honeybee populations in the honey industry has been a concern, their status as livestock means they are not at risk of extinction any time soon. In fact, it is believed that the global population of honeybees is higher today than at any other point in human history.
Despite this, one way homeowners have been taking action has been to set up backyard honeybee hives. While well-meaning, Professor Jeff Ollerton aptly explained, “Keeping hives to save the bees is like keeping chickens to save the birds.”
And, unfortunately, increasing numbers of non-native honeybees are out-competing Ontario’s wild bees for nectar and pollen. This, combined with a steady decline of native plants, is creating a dire situation for our native pollinators who are invaluable to our food crops and ecosystems. When we speak about saving the bees, it is our native pollinators we should be concerned about!
While honeybees can forage up to 5 kilometres from their hives, many native bees have extremely limited foraging ranges, with most staying under 500 metres from their nest. Adding a bee hive will add 15,000 - 50,000 hungry honeybees to an area who will be competing with the geographically limited native bees for nectar and pollen, in landscapes that already lack enough native flowers. A 2016 study shows that the amount of pollen needed to support a single bee hive could support 100,000 native bees!
In addition to outcompeting and displacing native bees due to sheer numbers, honeybees can also spread disease to native bees. Plus, most wild bee species have a short window—just a few days or weeks—when females are active and can reproduce. Adding to the challenge, many wild pollinators are picky eaters, relying on specific plants for food. Unlike honeybees, which can forage on a wide range of flowers, our native specialists depend on the right plants blooming at the right time.
Which bees are native to Ontario, and why do they matter?
Ontario is a national hotspot when it comes to bee diversity. Studies show that our province is home to an incredible 420 of the 855 bee species found across Canada. While too numerous to name, some categories of our native bee species are: bumble bees, squash bees, sweat bees, leafcutter bees, mason bees, miner bees and carpenter bees.
Some native bees (including bumble bees and a small number of sweat bees) form small colonies, with fewer numbers than honeybees. Most native bees, however, are solitary. They nest in the ground, hollow stems, twigs, and old logs, so refraining from “tidying” the garden is important for their survival.
Ontario native bees are crucial to the health of our ecosystems and maintaining our food crops. One third of the food we eat relies directly on pollination by bees, and bees play a key role in supporting healthy ecosystems and biodiversity through their relationships with native trees, shrubs, and flowers.
Having co-evolved with Ontario native plants, our native bees are better adapted to pollinate them than honeybees. Their body shapes/sizes and behaviours are ideally suited for specific flowers. Honeybees often lack these traits and behaviours, meaning that they sometimes contribute little or nothing to pollination.
For example, buzz-pollination, where bees use vibrations to remove and collect pollen from flowers, is an extremely effective pollination method that many native bees possess but honeybees lack. In some cases, honeybees can act as “nectar robbers,” collecting nectar without even touching the pollen. Professor Bryan Danforth, an entomologist at Cornell University, has argued that "native pollinators are two to three times better pollinators than honeybees."
In terms of our food, honeybees can’t pollinate all crops. Some crops, such as squash, tomatoes, eggplants, blueberries, and cranberries, rely on pollination by wild bees. And, once again, native bees are more effective pollinators of food crops. Their ability to buzz-pollinate crops increases fruit yield and seed number.
Orchard mason bees are especially efficient pollinators, visiting more flowers per hour than any other bee species. Just a few hundred of these hardworking bees can match the pollination output of 15,000 or more honeybees. Plus, since honeybees aren’t adapted to the cold here, they will only fly if it’s over 12 C. Many native bees, by contrast, will fly in 5 C or less! On cold spring or fall days, our native bees save the day.
The relative inefficiency of honeybees as pollinators is usually made up for by commercially introducing them to an area in vast numbers. In large numbers, they are effective when pollinating large monocultures in the industrial agriculture industry since they have a larger foraging range. But, of course, industrial monocultures are not supportive of our ecosystems or biodiversity, and the pesticides used on these crops are also harming bee health and numbers. The large numbers of honeybees used for pollination services in this way are also out-competing our important native bees.
Loss of Native Bees
In Ontario, 7 of the 14 bumblebee species found in surveys from the 1970s are absent or in decline. This is in line with broader trends showing that half of the bumblebee species in eastern North America are in decline, with 28% of bumble bee species listed as at risk and some facing a threat of extinction. Among them are species that were once a familiar sight, such as the rusty-patched bumble bee, the gypsy cuckoo bumble bee, and the American bumble bee. The rusty-patched bumble bee hasn’t been spotted in Canada since 2009, and is listed as endangered.
Further, researchers at York University found that climate change combined with a reduction in habitat, a reduction in native plant species, and an increase in non-native bee species in northeastern North America are likely responsible for a 94 percent loss of plant-pollinator networks over the last 30 years.
“About 30 percent of plant-pollinator networks were completely lost, which translates to a disappearance of either the bees, the plants or both. In another 64 per cent of the network loss, the wild bees, such as sweat or miner bees, or native plants, such as sumac and willow, are still present in the eco-system, but the bees no longer visit those plants. The association is gone.”
Choosing the Right Plants to Save the Bees
So, how can we use our gardens to save the bees?
Let’s start by addressing the elephant in the room: the lawn. Most urban and suburban lots are dominated by turf grass, which is not native and not supportive of any kind of bees. If possible, reducing lawn cover to make space for ecologically supportive gardens will go a long way.
But what plants will support our ecology? Beyond the lawn, most gardens include a majority of non-native perennials, shrubs, and trees. In fact, the vast majority of plants sold in nurseries are non-native, including several species that are invasive in Ontario! This is partly because our native plants were labelled as “weeds” by colonizers, and have been progressively wiped out as industry, commercial agriculture, and suburban sprawl take over more and more territory. It is also because companies can’t patent straight native species, so there is less money to be made by selling ecologically supportive native plants.
But gardens full of non-natives are primarily helping honeybees, not our native bees. Many of the early blooming plants and groundcovers promoted to save the bees are non-native, and are thus not ideal for supporting the bees that really need help.
Dandelions? Honeybees. Spring bulbs? Honeybees. Clover? Honeybees.
The best way to save and support native bees is to plant diverse communities of native flowers, grasses, trees, and shrubs and ensuring that there are plants in bloom all year round. Some bee-friendly native flowers include:
Wild Lupine
Spring-blooming:
Wild Strawberry (Fragaria virginiana)
Virginia Waterleaf (Hydrophyllum virginianum)
Eastern Red Columbine (Aquilegia canadensis)
Golden Alexander (Zizia aurea)
Wild Lupine (Lupinus perennis)
Foamflower (Tiarella cordifolia)
Foxglove Beardtongue (Penstemon digitalis)
Black-Eyed Susans (Rudbeckia hirta)
Blue Vervain (Verbena hastata)
Joe Pye Weed (Eutrochium purpureum)
Dense Blazing Star (Liatris spicata)
Anise Hyssop (Agastache foeniculum) (*this is a near-native)
Summer-blooming:
Scarlet Bee Balm (Monarda didyma)
Wild Bergamot (Monarda fistulosa)
Spotted Bee Balm (Monarda punctata)
Pale Purple Coneflower (Echinacea pallida)
Swamp Milkweed (Asclepias incarnata)
Butterfly Weed (Asclepias tuberosa)
Obedient Plant (Physostegia virginiana)
Joe Pye Weed
New England Aster
Fall-blooming:
New England Aster (Symphyotrichum novae-angliae)
Heath Aster (Symphyotrichum ericoides)
Smooth Blue Aster (Symphyotrichum laeve)
Bluestem Goldenrod (Solidago caesia)
Upland White Goldenrod (Solidago ptarmicoides)
Zigzag Goldenrod (Solidago flexicaulis)
Many flowering native trees are also pivotal in supporting native bees, as they bloom quite early in the spring. See: Native Trees in Ontario that are Pollinator Powerhouses
In addition to re-naturalizing your yard, there are some other important steps to take to support Ontario’s native bees.
Refrain from “tidying” the garden in fall and spring. Leave the fallen leaves on the ground as they provide shelter for ground-nesting bees. Leave dead flower stalks, some open ground, and woody debris to provide places for native bees to nest.
Minimize disturbing the ground in the fall and early spring to protect the nests.
Avoid pesticide use.
Provide shallow water sources, like bird baths or small dishes of water that native bees can use for hydration. Placing rocks or twigs in the water will give bees places to land.
