Bumblebees: key players for
a healthy landscape
Sometimes you have to get to the end of the season to appreciate the beginning.
It was early on a chilly October day when I went out to pay my respects to the finale of the season: several extraordinarily healthy stands of Symphyotrichum cordifolium, a sort of grey-lavender clouds of tiny flowers that waited for all the other asters to pack it in before taking their turn.
As it happens, I wasn't their only visitor. A lone bumblebee, probably a drone, was methodically working one of the patches, moving very slow because even its furry coat wasn't effective against the morning chill. It probably had less than a week to live, but kept plugging away, visiting as many blossoms as it could manage, dusting a little pollen here and there. And so I admired its dedication and made some photographs as a sort of salute, then felt a bit guilty because I eventually got too close for its own sense of comfort and it revved up its wings and lumbered off to parts unknown.
Of course, common blue wood asters are easy. Even I can grow them in vast numbers. Like its cousin, S. divaricatus, blue wood asters are sturdy, cheerful perennials that loft seeds by the thousands in the firm belief that you just can't have too many of them in the woodland landscape. It's a good doer that doesn't ask for much in the way of soil fertility or rainfall and normally grows to about 18 inches. Mine are in pretty good loam and get to about three or four feet, branch and bloom profusely and wait patiently until white asters are gone before taking the stage.
And, yes, the bumblebees are eagerly waiting for them. My little drone was one of a series that had worked through larval stages, took wing, pitched in to help the colony and eventually mated to create next year's queens. When the trees shed their leaves, the entire colony of bumblebees will perish with the exception of the young queens, however many there may be. They'll look for a place like an abandoned mousehole to hibernate until spring.
In a testimony to the incredible balance of nature and all its seasonal timings and triggers, the queens emerge and pounce upon the first flowers of spring, the ones we eagerly visit to celebrate the arrival of the gardening season. By now they're the biggest of the bumblebees and waste no time setting up housekeeping and laying the eggs that will become regular teams workers. These quite literally work themselves to death on behalf of the queen and the colony.
I understand that bumblebees and traditional honeybees are the only social species in North America, which means they're the only ones with stingers (to defend the colony). And because bumblebees nest in ground colonies, like under flat stones, they can and do have encounters with people and other creatures that go stomping through the areas bumblebees like to visit. It seems that only skunks are immune to the threat of an angry or frightened bumblebee.
As the season progresses, new bumblebees look for fresh source of food. Amazingly opportunistic, they quickly organize a feeding habit and pursue it relentlessly. If you are in the neighborhood, they'll probably check you out, too. Bumblebee enthusiasts encourage you to not do anything threatening, like running about in circles, frantically waving your arms and shrieking in fear. Instead, stand still, give the bee a break, and it'll quickly conclude that you're worthless. It will then get back to work and you can back away or, keep your distance and admire a genuine working stiff putting in a good day's work.
We all know plants produce flowers and encourage insects to visit with some sort of treat in exchange for sharing some pollen, but there's a case to be made for considering the natural landscape in the full seasonal sense and in good quantity. A bumblebee queen is going to set up shop in an area where there's a likelihood that there will be a supply of flowers from very early spring until late fall. Like all living creatures, they have work through a cycle to establish the generation for next year. Plants have evolved to understand this, and if you take notice, there's not a whole lot of competition at any given time in a balanced habitat.
If you've organized your native plants in close proximity, the bumblebees and other propagators will do you a real favor and flit from flower to flower on different plants. In these circumstances, they're cross-pollinating and that will produce healthier and more prolific seed. If not, they self-pollinate and take their chances with weaker and fewer seeds. Pollen from one species to another is wasted. A good landscape design, then, offers the bees a running buffet and good density to build succeeding generations.
Asters and anemones are enthusiastic, but some species are more challenging, even for bees. There's about forty different varieties of bumblebees, some of whom have very specific tastes. And an overall balance in the larger species involves bees with different length tongues that have adapted to flowers that are just a bit more coy. Epigaea repens is one of those plants that you either have or you don't because it's so difficult to propagate and nearly impossible to transplant. The flowers are early, the seeds are barely dust, and trailing arbutus is really fussy about where it grows. Mitchella repens puts up a pair of tiny tubular flowers, both of which have to be pollinated to form the single berry that produces seed to be dispersed by small mammals.
Even then, bees have a lot of competition. Plants enlist bees, wasps, ants, flies, butterflies, spiders and others in the struggle to survive and expand. Cohosh and dogbane loft spires of blossoms that wave more because of the crowd of insects coming and going than the summer breeze. Milkweed is an open bar with a happy hour that intoxicates all kinds of bugs, none of whom we give credit for when it comes to creating the stands of habitat that becomes condos for the butterflies we like to attract to the garden. Vast stretches of suburban lawns or insecticides don't help the cause, unless a lot of clover is tarnishing the homeowner's prized turf. When there's a broken link in the chain, populations can go into decline, and while a lot of folks might not worry too much about a shortage of bees, flies and wasps, most would agree that a collapse in plant life is not a good idea.
I once badgered a friend of mine, a botanist in the expert class, on a biological detail that I've long forgotten. But I took note of his exasperated reply. He rattled off some numbers with a lot of commas and zeroes about the numbers of species on the planet and said that after all the research so far, only the tiniest fraction of a percentage was known. There's a boggling amount of stuff yet to learn. So what value does a rue anemone or a woodland sunflower have? The literature notes nothing (yet) in terms of nutrition, pharmacy, or medical. Just a kind of useless plant.
Maybe. Maybe not. We don't know for sure.
If nothing else, it occurs to me that the "useless plant" is part of a chain of sustenance for things like bees, which somewhere along the line may very well be pollinating a plant that's crucial to our future.
If you want to ensure the future of plants, you have to ensure the future of bumblebees.
On the other hand, bumblebees aren't as enthusiastic about environmental responsibility as we might like. If you've got a nice patch of invasive plants (like the ever-dreaded purple loosestrife) hanging around the native plants, the bees will be mightily tempted by the luscious opportunity of the invasive and ignore the native. Invasives are flashy, exciting, seductive and we've just learned another reason to get them out of the landscape. If the native isn't pollinated, the future for the species is just a bit more bleak.
We often read about environmental responsibility in large scale. Greenhouse gases, water pollution, acid rain, over fishing, rain forests burning are alarming. The protection of vast tracts of wilderness through the intervention of powerful political forces gives us hope. But what action can one person take? Plant a small garden. Don't limit yourself to one or two species, but create a little habitat where there's a succession of blooming from very early spring until the frost comes. Keep the invasives away to give them a chance at propagating just a little bit. You might want to be sure to include species that are endangered or threatened. Yep, you'll have to do a little work organizing a shopping list and a landscape plan that's correct for your specific area, but in doing so you'll get personally acquainted with the astonishing system plants and insects have evolved for making a contribution to the environment.
Invite a bumblebee or two, and maybe some other six-legged characters, to lunch.
By doing so, you're making a direct impact on the health of the planet. You've gone from property owner to steward of the land. You've gone from being a consumer to a citizen of the whole Earth. And that's a good thing.
