About Lucas Costner

I am an undergraduate student majoring in Horticulture with a focus on Ecological Landscapes and Urban Forestry. Motivated by the belief that improving human habitat also means working with and blurring the line between the built and natural worlds, I am primarily interested in the interrelations between ecology, sustainability, and horticulture in urban environments.
Image from: http://www.nwplants.com/

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

Original “Plant of the Week: Douglas Aster” post available here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/07/plant-week-doulgas-aster/ 

 

Last November I took a look at a Pacific Northwest favorite, the Douglas aster (Symphyotrichum subspicatum (1)). What I didn’t know then was just how popular this species would be with the bees we had been sampling in the field. It turns out that while surveyed gardeners ranked Douglas aster 14 out of 27 in terms of attractiveness, based on the 2017 data it boasted the third highest number of bees (2). This means that it is the most attractive native perennial species for bees that we sampled, and the 2018 data shows this as well (3). Based on the gardeners’ ranking, however, which placed it in the bottom 50% of all the species we sampled, it also looks as though the Douglas aster is in need of some public relations help. 

It is my personal belief that it isn’t just the showiness of the blooms or the potential benefits to X, Y and Z that brings plants into our gardens, but rather the stories we tell about them. Familiarity after all is more than just recognition; it is also marked by appreciation and understanding. One of the stories we can tell through our work in the Garden Ecology Lab about Douglas aster is of its relationship with our native bees. As gardeners we are uniquely positioned to both benefit from and to be of service to these insects. 

Here are some of their “faces”: 

Long-horned Bees

Melissodes sp. 

The most common genus of bees collected from Douglas aster in the field, Melissodes are true summer and fall flyers, easily recognizable by their long antennae. These bees are solitary ground nesters, although they have been observed forming nesting aggregations in the soil (4). While we collected potentially five species of Melissodes in total, one species in particular, Melissodes microsticta, was especially common. Many Melissodes species are generalists, but can usually be found visiting members of the Asteraceae family (such as sunflowers and our Doulgas aster) because of their late season blooms.

 

Image from: https://odabeeguide.weebly.com/melissodes.html

Yellow-faced Bumblebee

Bombus vosnesenskii

The second most commonly collected visitor of Douglas aster, the yellow-faced bumblebee is really a remarkable native pollinator. While many native bees are considered solitary, bumble bees are social insects, with a queen and workers (4). Like non-native honeybees, they have been investigated for their potential as commercial pollinators, being used in greenhouse production (5). Isabella Messer wrote a post for the “Pollinator of the Week” series highlighting these ubiquitous bees that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/08/29/pollinator-week-yellow-faced-bumble-bee/ 

 

Image from: https://odabeeguide.weebly.com/bombus-sp.html

Ligated Furrow Bee

Halictus ligatus

The third most commonly collected visitor of Douglas aster is the ligated furrow bee. Found throughout North America, Halictus ligatus is special amongst native pollinators (like the yellow-faced bumblebee) for its social nature (4). Sociality is rare amongst native bees, as it is in nature in general, but amongst the Halictus the situation is even more unique. This is because, unlike other social species, Halictus have been seen to switch back and forth between solitary and social behaviors over time as environmental conditions differ (4). Isabella wrote a post about these bees a while back for the “Pollinator of the Week” series that can be read here: http://blogs.oregonstate.edu/gardenecologylab/2018/04/30/pollinator-week-mining-bee/ 

 

Image from: https://odabeeguide.weebly.com/halictus.html

Virescent Green Metallic Bee

Agapostemon virescens

The fourth most commonly collected visitor of the Douglas aster is none other than my personal favorite, the virescent green metallic bee. These stunning bees are communal soil nesters and are members of the Halictidae family, cousins of the ligated furrow bee introduced above (4). I wrote a post about them for the “Pollinator of the Week” series last November that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/13/pollinator-week-virescent-green-metallic-bee/ 

 

Image from: https://odabeeguide.weebly.com/agapostemon.html

In addition to these bees, we also collected striped-sweat bees (Agapostemon texanus/angelicus), brown-winged furrow bees (Halictus farinosus), metallic sweat bees (Lasioglossum sp.), and common little leaf-cutter bees (Megachile brevis). We also collected with a number of long-horned bees (Melissodes) that have yet to be identified to species. 

Walking the streets of Portland and seeing Douglas aster’s purple flowers still in bloom this late in October brings a smile to my face because it tells me that people are indeed planting this species. If only for its benefit to wildlife and pollinators in particular, that is still good news. As you may be able to tell from the information given above, we are still learning about these bee species while we are simultaneously working to save them — not just for future generations but for ourselves as well. Hopefully, by putting a “face” to the bees that visit and depend on these plants and our gardens, the bond that links us to them can be strengthened and our preference for them in our landscape enhanced. 

 

Sources: 

  1. Geraldine A. Allen 2012, Symphyotrichum subspicatum, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=88843, accessed on October 30, 2018.
  2. Langellotto, G. (2018, September 12). Do Gardeners Like the Same Flowers as Bees? [Blog post]. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/09/12/do-gardeners-like-the-same-flowers-as-bees/ 
  3. Anderson, A. (n.d.). First Look: Research Into Native Plants in the PNW Garden. Webinar. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/10/23/webinar-on-willamette-valley-native-plants-and-pollinators/ 
  4. Wilson, J. S., & Messinger Carril, O. (2016). The Bees In Your Backyard. Princeton, NJ: Princeton University Press.
  5. Dogterom, M. H., Matteoni, J. A., & Plowright, R. C. (1998). Pollination of Greenhouse Tomatoes by the North American Bombus vosnesenskii. Journal of Economic Entomology, 91(1), 71-75. doi:https://doi.org/10.1093/jee/91.1.71
  6. Oregon Department of Agriculture: Bee Pollinators of Oregon. (2016). Retrieved October 30, 2018, from https://odabeeguide.weebly.com 

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

As summer in the Pacific Northwest comes to a close, the sunflower (Helianthus annuus) stands out as a classic garden favorite deserving consideration. These commonly large, tall yellow flowers are a boon to wildlife, provide late summer height and interest in the garden, and have shared an interesting relationship with people wherever we have encountered them. 

While there are many individual species and varieties available on the market today, wild populations can be found across North America, and most boast popularity with insect pollinators and other wildlife, including birds (1, 3). In the field, Aaron is using the wild-type and, while you certainly don’t have to do the same, varieties marked as “pollenless” or double-petaled should be avoided when planting for wildlife (3). Sunflowers seeds are well-known for their attractiveness to birds, but the flowers also provide forage to a diverse suite of insects, including bees, wasps, butterflies, and even beetles (2, 3). Four genera of native bee species (Diadasia, Eucera, Melissodes, and Svastra) host members that are sunflower specialists, and the giant leafcutter bee (Megachile pugnata) has even been studied as a managed pollinator for agricultural production of the crop (3). 

The giant leafcutter bee (Megachile pugnata).  Photo Credit: Thomas Shahan. Oregon Department of Agriculture.

Originally domesticated in eastern North America, the sunflower is the only native seed oil plant (1). Its use among North America’s indigenous peoples is well-documented and varied, having been used for everything from food to dye to medicine (2). The sunflower was introduced to Europe in the 16th century, where it first found its place in gardens, but it wasn’t until the 1800s in Russia that our modern ideas of giant, towering sunflowers came to be (1). This is because early American colonists did not cultivate sunflowers, and the seeds were reintroduced from Russia to the United States in 1893 (2). The Russians bred sunflowers that could produce up to 1000 seeds each for oil production, since the Russian Orthodox Church had forbidden the use of other cooking oils during the Lenten season (1). Therefore, in comparison with many common varieties available, and despite 3,000 years of domestication by indigenous peoples in North America, the wild-type appears quite diminutive (2). 

No matter the variety, gardeners should be aware that sunflowers are annual flowers that will need replanting every spring (although allowing squirrels to do the planting could be a fun experiment). They prefer well-draining soil and can reach rather impressive heights depending on the exact species and type. Additionally, the stems can become woody and may require some work removing at the end of the season. 

Sources cited: 

  1. Simpson, B. B., & Connor, M. (2014). Plants in Our World: Economic Botany (4th ed.). New York, NY: McGraw-Hill Education.
  2. Stevens, M. (2006, June 7). Plant Guide: Annual Sunflower [PDF]. Davis: USDA NRCS National Plant Data Center.
  3. The Xerxes Society. (2011). Attracting Native Pollinators. North Adams, MA: Storey Publishing.

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

Common Yarrow (Achillea millefolium) isn’t just common — it’s nearly ubiquitous throughout the Pacific Northwest. Found in lawns, along roadsides, in fields and gardens, it’s easy to allow yarrow’s abundance to overshadow its potential in the landscape, its benefit to wildlife, and its historical value as a medicinal plant. 

A perennial native across the temperate Northern Hemisphere, yarrow has a long history of human association (1, 2). Its scientific name, Achillea, comes from the ancient Greek hero Achilles, who used the plant to help dress battle wounds (2). Similarly, in the Northwest, indigenous peoples made poultices and teas from the plant (2). 

In the landscape, it may be helpful for gardeners to consider mimicking natural distribution patterns by massing yarrow into larger groups of plants (3). Yarrow grows densely — emerging up to three feet in height and spreading from a fibrous horizontal root system (1). White, sometimes pink, ray flowers appear at the end of stems in nearly flat inflorescences (2). These plants are very drought tolerant and appear naturally in disturbed areas, meaning they will thrive in the average garden (1). 

As a member of the Asteraceae family along with goldenrod and Douglas aster, yarrow’s bountiful floral display offers excellent forage for generalist pollinator species throughout the summer months and is a common choice for butterfly gardens (1). In addition to its floral resources, the foliage is noted as a source of food and habitat to many species of butterfly and moth caterpillars (4). 

References: 

1. Hurteau, M. D. (2013, November 13). Common Yarrow [PDF]. USDA NRCS National Plant Data Center.

2. Mathews, D. (2016). Natural History of the Pacific Northwest Mountains. Portland, OR: Timber Press.

3. Rainer, T., & West, C. (2015). Planting in a Post Wild World. Portland, OR: Timber Press.

4. Robinson, G. S., P. R. Ackery, I. J. Kitching, G. W. Beccaloni & L. M. Hernández, 2010. HOSTS – A Database of the World’s Lepidopteran Hostplants. Natural History Museum, London. http://www.nhm.ac.uk/hosts. (Accessed: 29 Aug. 2018).

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

A native been rolls around inside of a California poppy at the North Willamette Research and Extension Center.

Having moved to Oregon from Michigan this past spring, one of my first memories of the state was the explosion of bright orange and yellow flowers lining the interstate and covering the hills. These ubiquitous flowers were, of course, California poppies (Escscholzia californica). Native to a range covering southern Washington south to the Sonoran Desert, the plant has spread throughout most of North America and onto other continents thanks to human intervention (1). This should come to no surprise to those familiar with the plant, because it is easy to grow and thrives in average soil, as long as drainage is good and there is plenty of sun (3).

California poppies can be grown as perennials or annuals, depending on the severity of the winters (3). The grey-green, finely divided foliage erupts with brightly colored flowers in the spring, but can continue flowering across the growing season if conditions are favorable (1). Long, spindly seed pods appear quickly following pollination and, once dry, easily explode, spreading baby poppies up to six feet away from the parent plant (1). If you’re looking to add these beauties to your own garden, it is best to spread seeds on the surface of the soil in the fall to ensure that dormancy is broken (1). But gardener beware: once established, California poppies are around for the long haul (3).

These flowers have been grown or collected for hundreds of years by the societies that have encountered them (1). Indigenous North Americans first used the plants for a variety of medicinal purposes and the plant quickly rose to fame in Victorian gardens after it was collected by David Douglas for the Royal Botanical Society of England in 1836 (1, 3). Western medicine has also found use of the California poppy, isolating over 30 chemicals for uses ranging from anti-bacterial agents to the treatment of cancer (1). For horticultural purposes, the Royal Horticultural Society today recommends planting along borders, for cut flowers, to create a sense of informality as in a cottage garden, as well as for gravel and rock gardens (4).

The act of gardening is unique in that it strikes a balance between control of and surrender to the natural world. On the one hand, the plants we decide to grow on our little slices of paradise are an irrevocable extension of us and our own stories; however, these plants have their own stories to tell and they transform us into participants of these stories whether we are willing or not. I’ve never heard anyone say, for example, that they planted such-and-such prize-winning hosta to attract deer to their garden. Yet, when these majestic 150-pound creatures sneak silently into our yards for a midnight snack, it’s hard to argue they weren’t invited. The plants we choose act as our ambassadors to a biotic world just beyond our grasp, providing food and habitat for a full spectrum of wildlife. On a larger scale, the landscapes we cultivate can collectively affect everything from water resources to the climate.

While it’s true that I’ve never heard anyone say they are planting for the deer, us gardeners have certainly taken a liking to another sort of creature. The insects of the Anthophila clade, otherwise known as the bees, have found a special place in our hearts. Maybe writer Michael Pollan was on to something when he recognized, in The Botany of Desire, the mirrored way in which the bees visiting his garden had found themselves in the servitude of the plants just as he was. While the gardener tends to the plants’ every need, the bee unwittingly ensures their reproductive success by transporting pollen from flower to flower. Or maybe its the recognition that we ultimately depend on pollinators for our own food security and survival. Whatever the underlying cause behind our species’ admiration of bees, cultivating a diversity of flowers is the surest way to invite them to and help them persist in our landscapes.

A syrphid fly pays a visit to a California poppy at the North Willamette Research and Extension Center.

Whether you sow the seeds of the California poppy simply for its beauty, for its natural history, to help prevent erosion, or for any other reason, you will also inevitably be providing a source of food for our favorite insects, the bees. Surprisingly California poppies don’t provide nectar for pollinators, just pollen, but they are still heavily visited by our native bumblebees, sweat bees, and mining bees, as well as the European honey bee (Apis mellifera) (1, 2). They are also visited by beautiful butterflies, beneficial minute pirate bugs, and glistening beetles (1). Additionally, from our observations at the North Willamette Research and Extension Center, I can personally attest to the California poppy’s popularity amongst a variety of syrphid flies.

As a student interested in creating functional habitat for both humans and wildlife, it truly matters little to me on its face if a plant is native or not. Gardens consisting of native plants can be just as gorgeous and moving as gardens consisting of exotic species — this is true. What does matter to me are the relationships these plants have with other organisms, and what that looks like in a world increasingly and unavoidably modified by humans. So, whether or not you decide to bring the California poppy or any other native plants into your own garden, I hope you do feel inspired to think about these plants in terms of their role in the wider community of life with which we share this planet.

Sources:

  1. Smith, C. 2010. Plant guide for California poppy (Eschscholzia californica). USDA-Natural Resources Conservation Service, Plant Materials Center. Lockeford, CA 95237.
  2. Garvey, Kathy Keatley. “Why Honey Bees Forage in California Poppies.” Bug Squad: Happenings in the Insect World, University of California, 18 Mar. 2014, ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=13179.
  3. Nelson, Julie. “California poppy (Eschscholzia californica).” Plant of the Week, USDA Forest Service Rangeland Management & Vegetation Ecology – Botany Program, www.fs.fed.us/wildflowers/plant-of-the-week/eschscholzia_californica.shtml.
  4. “Eschscholzia californica.” Royal Horticultural Society, www.rhs.org.uk/Plants/106119/Eschscholzia-californica/Details.
A female virescent green metallic bee. Image from United States Geological Survey Bee Inventory and Monitoring Lab.

This entry is from Lucas Costner, an undergraduate horticulture student at Oregon State University. It highlights a common Oregon pollinator.

While there are approximately 4,000 species of native bees in the United States (an estimated 500 of which call Oregon home), I’ve decidedly landed on one as my very favorite (1, 2). This flying iridescent blue-green gem, covered in golden hairs, and sporting a pitch black abdomen with white or yellow bands is Agapostemon virescens, the virescent green metallic bee. Found throughout the United States and southern Canada, these members of the sweat bee family (Halictidae) are common and beautiful (3).

As with other species of the genus Agapostemon, the virescent green metallic bee is a communal soil nester (3). These nests are composed of underground tunnel systems, marked by a main vertical burrow that branches off into several larger nesting areas complete with horizontally running tunnels and cells (4). In these cells, female bees leave a gift of pollen and nectar for a single egg before filling the tunnel with an insulating layer of soil (4). Soon a babe is hatched and, after eating and growing, the mature offspring dig their way out to start foraging!

Virescent green metallic bees are polylectic, meaning they collect pollen from a wide variety of floral resources (4). This is lucky for us gardeners, because we can plant from over a dozen common flower genera and provide the bees with forage. This point is underscored by a 2014 study that sampled bee species in Chicago, finding that the virescent green metallic bee was one of the most common species in the city (5). The same study noted that in more densely populated neighborhoods, the overall composition of bees shifted to more heavily consist of  bees like the virescent green metallic bee and the European honey bee (5). As our cities continue to grow and the needs of urban communities become more pressing, this is good news for the virescent green metallic bee and other generalist pollinator species that can benefit from a relatively wide selection of floral resources.

A virescent green metallic bee emerging from a nest. Image from the University of Maine Cooperative Extension.

Having met the virescent green metallic bee for the first time this past summer working with Aaron Anderson on his native plants study at the North Willamette Research and Extension Center, I was curious to see which plants selected for the study had been previously identified as providing forage for the bee. From our list, the common sunflower (Helianthus annuus), yarrow (Achillea millefolium), showy milkweed (Asclepias speciosa), Douglas aster, (Symphyotrichum subspicatus), common camas (Camassia leichtlinii), wild strawberry (Fragraria vesca), Oregon iris (Iris tenax), sedum (Sedum oregonense), and goldenrod (Solidago canadensis) all make the cut (3).

Flowers are important for these bees for more than just food, however; as they also provide a rather scenic backdrop for the crucial business of mating. While female bees will return to the nest after emerging from the incubator cells in the spring, the male bees spend their days foraging, mating, and sleeping out in the cold, eventually dying at the end of the season (4). The females are the real beneficiaries of the underground nests, returning here to hibernate and lay their own eggs, and sharing in the joint responsibilities of guarding and maintaining the tunnels (4).

My favorite green bee may be relatively abundant and may not require as much help as other species in the way of specific planting regimes, but (as with all native ground nesting bees) leaving some undisturbed open space in your yard or garden can go along way to provide habitat. According to the Xerxes Society, nearly 70% of all native bees are ground nesters (6). To offer nesting habitat in your garden, simply leaving a couple feet of well-drained, bare or sparsely vegetated soil available in a sunny location will do (1, 6). The bees will take care of the rest — hopefully you will have the opportunity to enjoy them in your own garden next summer!

Sources:

  1. Moisset, Beatriz, and Stephen Buchmann. “Bee Basics: An Introduction to Our Native Bees.” USDA Forest Service, Mar. 2011.
  2. “Oregon Native Bee Atlas.” Oregon Bee Project, blogs.oregonstate.edu/beeproject/bee-atlas/.
  3. “Agapostemon virescens.” Discover Life, 9 Nov. 2017, www.discoverlife.org/mp/20q?search=Agapostemon%2Bvirescens.
  4. Abrams, Judith, and George C. Eickwort. “Nest switching and guarding by the communal sweat beeAgapostemon virescens (Hymenoptera, Halictidae).” Insectes Sociaux, vol. 28, no. 2, 1981, pp. 105–116., doi:10.1007/bf02223699.
  5. Lowenstein, David M., et al. “Humans, bees, and pollination services in the city: the case of Chicago, IL (USA).” Biodiversity and Conservation, vol. 23, no. 11, Oct. 2014, pp. 2857–2874., doi:10.1007/s10531-014-0752-0.
  6. Shepherd, Matthew. “Nests for Native Bees.” The Xerxes Society for Invertebrate Conservation, 2012.

This entry is from Lucas Costner, an undergraduate horticulture student at Oregon State University. It highlights a common Oregon pollinator.

A common feature of the urban and suburban landscape, a street lined with large London plane trees (Platanus x acerifolia), complete with lumpy trunks and exfoliating bark, can be a delight to behold. The tree was the favorite species of New York City planner Robert Moses, and became one popular choice for replacing elms affected by the infamous Dutch elm disease during the previous century (1). Chosen for its long life span, interesting growth habit, and ability to withstand the challenges of street life, the London plane has become a ubiquitous member of our cultivated environment. By happy accident, the tree also plays host to the larvae of the familiar and striking western tiger swallowtail (Papilio rutulus) (3).

This large yellow and black butterfly is found throughout the western continental United States and into southern British Columbia. Swallowtails tend to be specialists (2), so the addition of known host trees like the London plane and other members of the Platanus genus, along with willows (Salix spp.), poplars (Populus spp.), and alders (Alnus spp.) is of benefit not only to our parks, streets, and yards, but to these incredible pollinators as well (3). Adult females lay single eggs on the undersides of the leaves of host trees, which then provide food for the developing larvae (4). These larvae eventually form chrysalids and overwinter, emerging the following season as, well, beautiful butterflies (4). While the larvae of the western tiger swallowtail have somewhat specific tastes, the adult butterflies will feast on nectar from many flowering species. These pollinators typically take flight from June through July, but in Pacific coastal areas may be found throughout much of the year (3). They are noted as preferring wetter areas generally, and even as being avid visitors to mud-puddles (5).

Butterflies are of course important to us as gardeners because of the pollination services they provide, but throughout their lifespan they also play an important role as food for other organisms. Douglas Tallamy, from the University of Delaware, writes “if we were forced to care for only one group of insects in our restored suburban ecosystem, we would do well to choose the Lepidoptera” (the order consisting of moths and butterflies) (2). Fortunately for the western tiger swallowtail, and for those of us who enjoy its beauty, our cultivated landscapes should provide ample habitat. With that being said, global declines in flying insects are being documented (see: Insects are In Serious Trouble), and our attention needs to remain fixed as much on what we are planting as on how we are managing these landscapes.

Personally, I wasn’t fortunate enough to see many species of Lepidoptera this past season. I did manage to catch sight of a western tiger swallowtail early in the year, however, at the North Willamette Research and Extension Center foraging on a patch of showy milkweed (pictured above) neighboring the native plants study plot. Being a recent transplant from east of the Rockies, this was my first time ever seeing the butterfly and I was truly blown away. I’m hopeful that despite the challenges faced by these and other pollinators, we will all be able to enjoy them well into the future.

Sources:

  1. Jonnes, Jill. Urban Forests: A Natural History of Trees in the American Cityscape. Penguin, 2017.
  2. Tallamy, Douglas W. Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens. Timber Press, 2007.
  3. Haggard, Peter, and Judy Haggard. Insects of the Pacific Northwest. Timber Press, 2006.
  4. “Western Tiger Swallowtail.” Butterflies and Moths of North America, 21 June 2016, www.butterfliesandmoths.org/species/Papilio-rutulus.
  5. Layberry, Ross, et al. “Western Tiger Swallowtail.” Butterflies of Canada, Canadian Biodiversity Information Facility, 9 July 2014, www.cbif.gc.ca/eng/species-bank/butterflies-of-canada/western-tiger-swallowtail/?id=1370403265809.
Image source: https://www.flickr.com/photos/12567713@N00/2809146063

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

A common and much-beloved Northwest native, the Douglas aster, happens to be a bit of a misnomer. This profusely blooming, purple-flowered perennial isn’t a member of the Old World Aster genus, but rather belongs to the New World Symphyotrichum (2). As such, our Douglas aster (Symphyotrichum subspicatum) is closely related to its East Coast look-alike, the New England aster (Symphyotrichum novae-angliae), and evidence suggests the two descend from a common ancestor (2).

Naming conventions aside, the Douglas aster should be noted for offering an impressive, season-long (July – September) display of attractive, disk-shaped, and papery flowers while asking for little in return. Like many of the other native plants I have written about to this date, this plant is incredibly hardy and will spread via creeping rhizomes if given the opportunity (3). The USDA Natural Resources Conservation Service recognizes the Douglas aster as being abundant and present from Alaska to California, and into Idaho and Montana (1). In the wild, it is noted as being found in forests, along the banks of streams, and even along the coast (3).

In Oregon gardens, west of the Cascades, the Douglas aster will again require little in terms of care once established. It does prefer full-sun, and well-drained soil, but it similarly thrives in wetland areas (4). Our test subjects in the field faced many hardships, ranging from drought to over-zealous mowing, and still ended up thriving. Therefore, as with the majority of the native plants written about here, this plant may not be appropriate for every garden or indeed for every gardener. The most exciting part about the Douglas aster, however, is not its robust growth habit; but rather, its potential to benefit wildlife and therefore our suburban and urban environments.

In the field, other members of the Asteraceae family (think goldenrod and pearly everlasting) have anecdotally been some of the most popular plants in terms of pollinating visitors, and our Douglas aster plots were no exception. At times, it was hard to keep track of just which insects had or had not been counted during our five minute observations due to their sheer abundance. Thanks to the long bloom period, it was also exciting to the see the progression of pollinators develop as the season passed week by week, and the species composition gradually changed. While the Douglas aster is noted for its attractiveness to many species of butterflies, our observations could suggest that is similarly attractive to a fairly wide array of bees as well (4).

Sources:

  1. “Plant Profile for Symphyotrichum subspicatum subspicatum (Douglas aster).” Plants Database, USDA NRCS, plants.usda.gov/core/profile?symbol=SYSUS.
  2. Candeias, Matt. “How North America Lost Its Asters.” In Defense of Plants, 12 Oct. 2016, www.indefenseofplants.com/blog/2016/10/12/how-north-america-lost-its-asters.
  3. Knoke, Don, and David Giblin. “Symphyotrichum subspicatum.” WTU Herbarium Image Collection, Burke Museum of Natural History and Culture, biology.burke.washington.edu/herbarium/imagecollection.php?Genus=Symphyotrichum&Species=subspicatum.
  4. “Douglas Aster.” Washington Native Plant Society: Starflower Image Herbarium, 5 Nov. 2007, www.wnps.org/landscaping/herbarium/pages/aster-subspicatus.html.