October at Oaks Bottom: What One Native Aster Was Holding Up

Go down to Oaks Bottom in October, after the summer crowds have stopped coming and the trail is mostly dog walkers, and look at what is still in flower.

It will not take long. Almost nothing is. The meadow has gone tawny, the blackberries are finished, the willows are dropping. What is left is a scatter of pale lavender daisies standing above the dead grass, and if you stop at one and wait a minute, you will find it busier than anything you saw there in July.

🌼 There’s a quiz at the end — ten questions on what’s below. Jump to the quiz →

First, the Bird That Made This Place Famous

Portland has an official city bird, and this is it.

In the spring of 1986, the urban naturalist Mike Houck overheard Mayor Bud Clark at a conference, talking about the herons he had watched glide past downtown skyscrapers while paddling his canoe on the Willamette. Houck pitched him on the spot: make it the city bird. Clark gave it his trademark whoop, whoop, and two weeks later it was official. Portland has held a Great Blue Heron Week every year since.

It is a strange choice for a city, when you think about it. Not a songbird. Not a raptor. A four-foot wading bird that will stand in shallow water without moving for the better part of an hour, then unfold into six feet of wingspan and leave as though gravity were optional. But anyone who has watched one lift off the Willamette with the downtown towers behind it understands the decision immediately.

This one is in full breeding dress — the long shaggy plumes hanging off the breast and back, the black crest trailing from a white crown. Those plumes very nearly cost the species everything. In the late 1800s they were worth more than their own weight in gold on the hat market, and the slaughter of plume birds is the reason the Audubon societies exist at all. The bird you are looking at is here because people organized to stop it.

Now the Plant Nobody Photographs

This is Douglas aster, Symphyotrichum subspicatum, and everything in that frame is happening at once. One bloom fully open. Several already curled brown and gone to seed. A few buds underneath still coming.

That is the whole strategy. Douglas aster blooms late and blooms long, August into October, well past the point where the rest of the meadow has shut down for the year. It is not competing with the summer flowers. It is waiting for them to quit.

Which makes it one of the most important plants in the refuge and one of the least noticed. By the middle of October it is very nearly the only thing at Oaks Bottom still serving food. Everything that follows in this post — every bee, the thief that follows the bees, the butterfly — is here for that reason. There is nowhere else left to go.

It is native, it likes wet feet, and it spreads by running roots, which is exactly why it does well in a floodplain that goes under water every winter.

The Bees Still Working

The bees working an October aster are not the ones you saw in June.

By now the honeybees have gone quiet. The big bumblebee colonies that ran all summer have collapsed down to a few new queens, who are looking for somewhere to spend the winter rather than somewhere to forage. What is left on the flowers are the solitary bees — one female, one nest, no hive behind her and no workers to help — finishing out a season’s worth of provisioning on whatever is still open.

Everything a solitary bee gathers goes into a sealed cell with a single egg. She builds the cell, packs it with pollen and nectar, lays, seals it, and starts the next one. She will never meet the larva that eats it. By the time that egg becomes a bee, next summer, she will be months dead.

That is why a bee in October has a particular quality to her. She is not storing honey for a colony that will outlive her. She is filling the last few cells of her own life’s work, in the last week that there is anything to fill them with.

Watch where she actually goes. Not the petals — the yellow button in the middle. What looks like one flower is a daisy, and a daisy is not one flower at all. It is a dense packed head of dozens of tiny complete flowers, each one with its own nectar and its own pollen, and the lavender rays around the outside are billboards to bring her in. She works the disc one floret at a time, like someone going down a row of market stalls.

And the One That Does Not Work at All

Something is wrong with this one, and you can see it before you can name it. She is bare. Shining, hard-looking, boldly banded, more wasp than bee.

Bees are fuzzy for a reason. Every hair on a bee is branched, like a tiny feather, and the whole coat works as a pollen trap — it is equipment. A bee with no fuzz is not carrying anything, because she is not collecting anything.

This is a cuckoo bee. She does not build a nest and she does not gather provisions. She finds the burrow of another bee — one who has spent days packing a cell with pollen for her own young — slips in while the owner is out foraging, and lays her egg in it. Her larva hatches first, kills the host’s egg, and eats the food that was stored for it.

Here is the part that surprises people. About one bee species in six, worldwide, lives this way. They are not rare, and they are not a flaw in the system. A cuckoo bee can only exist where its host is common enough to be worth robbing — she has to be able to find nest after nest after nest. A patch of ground that supports a population of cuckoos is a patch of ground that is doing very well indeed.

So when you find one, the news is good. I have seen them in this same part of Oaks Bottom in other years, working the same asters, hanging around the same bees. That is not a coincidence and it is not an accident. She is there because they are there.

The Butterfly Built Like a Fighter Plane

Skippers are the butterflies most people walk straight past. Small, orange, fast, and built more like a moth than a monarch — thick in the body, short in the wing, flying in quick darting jerks that gave the whole family its name.

This one is a Woodland Skipper, Ochlodes sylvanoides, the commonest skipper in western Oregon and the one that turns up on nearly every late aster in the refuge. They emerge in July and fly into October, timed to the last decent nectar of the year.

Two field marks, and the first is enough.

The antennae. Every true butterfly ends its antennae in a club. Skippers add a small hook at the very tip, bent back like a crochet needle. Once you have seen it you can call the family from across a meadow.

The wings at rest. That half-open posture — forewings cocked up at an angle, hindwings held flat — is a skipper and nothing else. Butterflies hold their wings together above the back. Moths lay them flat. Skippers do both at once.

And here is the thing worth carrying home: skipper caterpillars eat native grasses. So a skipper on an aster is not really telling you about the aster. It is a report about the grass underneath it. A meadow that gets mown flat every year has no skippers in it, however many flowers you plant.

What a Single Plant Was Holding Up

Count what was on that one stand of asters, in one afternoon, in the second week of October: solitary bees finishing the last cells of their lives. A cuckoo bee following them to steal those cells. A skipper taking nectar, with its caterpillars somewhere in the grass below. And a hundred yards away, standing in the shallows, Portland’s city bird.

None of that happens without a plant that blooms when nothing else will.

So I Bought One

At a native plant sale, a few days later: one Douglas aster rhizome, a knuckle of root in a bag, going into my own garden this fall.

If you want to do the same, it is about as easy as planting gets. Lay the rhizome horizontally, an inch or two down, any visible buds facing up. Firm it, water it once, and then leave it — Portland’s winter rain will do the establishing for you, which is why fall is the right time to put it in. Give it a sunny spot that does not bake dry in August. It is a floodplain plant; a low damp corner suits it fine.

Then give it more room than looks sensible, because it runs.

And one last thing, which is the single most useful sentence in this post: do not tidy it up in the fall. Leave the dead stems standing through the winter. Hollow and pithy stems are where small native bees overwinter — the very bees in these photographs. Cut it back in late winter if you must cut it at all.

The way to help everything in this post is to stop cleaning up.

Quiz: Ten Questions on October at Oaks Bottom