An Update on Native Plant Studies from The Garden Ecology Lab at Oregon State University

Posted on February 17, 2025 by Gail Langellotto

A version of this article was originally written for the ‘Growing Knowledge‘ section of Digger Magazine, published by the Oregon Association of Nurseries.

The Garden Ecology Lab was founded in 2017 to advance an understanding of how to plan, plant, and manage garden systems to promote environmental and human health. It is one of two labs in the United States, and the only one in the Western US, to specifically focus on studies of garden ecology.

In this article, I provide an update on our native plant studies, with a focus on results that may be of particular interest to nursery owners. Brief summaries of many of our lab’s studies can be found on the ‘For Gardeners’ page of our lab website. Some nurseries have printed out copies of these lab briefs, so that their customers can see the ecological benefits of various plants. More briefs are planned for this year. Periodically visit our website for updates.

Native Plants in Garden Retail Centers

Interest in native plant gardening has drastically grown in recent years, but many native plants remain difficult to find for purchase. In the April 2019 issue of The Digger, Dr. Aaron Anderson highlighted three barriers that gardeners face, when trying to purchase native plants: 1) lack of advertising by native plant nurseries or gardeners’ lack of familiarity with these nurseries, 2) variation in nursery stock among native plant growers, and 3) geographic distance that gardeners might have to travel to find the plants they are looking for. These specific barriers were ones that Aaron faced when he was setting up his field study of insect communities associated with 23 species of Pacific Northwest Native plants.

Aaron used the Oregon Flora’s gardening resource page to locate where he could buy his study plants. He ultimately ended up purchasing plants from two retail nurseries (one in Corvallis and the other in Forest Grove) and two pop up native plant sales (one in Corvallis and one in Portland). He also worked with two wholesale nurseries that were generous enough to sell or donate study plants or seed in the small quantities he was seeking (one in Salem and one in Silverton). Because he has been asked this question, often, Aaron also wrote a blog post on ‘Where to Buy Native Plants in Oregon‘.

After a three-year field study, Aaron was able to identify 10 native plants which support a diversity of bee species. We developed an infographic to share this information with gardeners, and include lavender in the image, since many gardeners perceive lavender to be a pollinator-friendly plant (Bennett 2019).

Image 1: The number of estimated bee species associated with PNW native plants is shown in a yellow circle, above each bar. Lavender is shown as a comparison, since it is recognized as a pollinator-friendly plant by many gardeners.

Today, Oregon Flora’s garden resource page lists 10 nurseries where gardeners can find and purchase native plants (Oregon Flora 2025). I used their plant-finding tool, to see whether I could find the 10 native plants that we recommend to gardeners. None of the nurseries were listed as carrying all of these recommended plants: two nurseries were listed as carrying 6 species, three nurseries carried 5, two nurseries carried 4, and three nurseries carried 2. All of the 10 nurseries were listed as carrying Oregon sunshine (Eriophyllum lanatum). None were listed as carrying Farewell-to-spring (Clarkia amoena), varileaf phacelia (Phacelia heterophylla), or common madia (Madia elegans).

Farewell-to-Spring, a promising native nursery plant

The absence of farewell-to-spring from nursery shelves is particularly disappointing, because it has become a favorite in our lab group. Its native range spans the Bay Area of California, north through Oregon and Washington and into British Columbia. In Oregon, it grows west of the Cascades to the coast and is found in a variety of habitats including coastal prairie, grasslands and forested areas. It is an easy-to-grow annual plant with erect stems (5.4” maximum height), thin, green leaves and bright pink flowers. In our study plots, first bloom occurred anywhere between early June and early July and lasting through early August through late October, depending upon seasonal weather patterns and supplemental irrigation.

Farewell-to-spring attracts a diversity of beneficial insects. Aaron collected 14 bee species, 15 predatory insect taxa, and 12 parasitoid taxa from this wildflower (Anderson 2022, Anderson et al. 2022) documenting its ecological value for attracting pollinators, as well as natural enemies that promote the biological control of insect pests. In a separate, but related field study, Jen Hayes looked at the pollinator assemblages on eight species of wild-type native plants and 1-3 of their cultivars. Jen provided an overview of this study in the October 2020 issue of The Digger (Hayes and Langellotto 2020), and the full report of this study was recently published (Hayes et al. 2025) for folks wanting more detailed information.

Farewell-to-spring was one of the native plants in her field study of pollinators on native plants and native cultivars. The cultivars she used were ‘Aurora’ (dark pink blossoms with a cream center), ‘Dwarf White’ (white blossoms), and ‘Scarlet’ (red blossoms with a light pink center). She documented 32 total pollinator species from the wild-type plant (with an estimated 104 total pollinator species), 17 pollinators on ‘Aurora’ (28 species estimated), 23 pollinators on ‘Dwarf White’ (24 species estimated), and 9 pollinators on ‘Scarlet’ (13 species estimated). Furthermore, she found that specialist bees, which are picky about where they collect pollen, were either exclusively found on wild-type native plants (two species, Megachile gravita and Melissodes microstictus), or were found in higher abundance on wild-type plants compared to cultivars (two species, Melissodes lupinus and Melissodes clarkiae). Because specialist bees have relatively narrow diet preferences, including their preferred forage plants is an easy way to attract these unique bees into a garden, and to locally increase pollinator biodiversity.

In addition to the importance of wild-type Farewell-to-spring as a forage plant, Jen worked with Mallory Mead (a former undergraduate student in our lab) to document its importance for bee nest material. Many leafcutter bee species use leaves, mud, resin, sticks, pebbles, or petals when they build their nests. Jen documented two species of petal-cutting bees in her study plot, each of which had a significant association with Farewell-to-spring and its cultivars. Megachile montivaga had significant associations with the wild type native and ‘Dwarf White’. Megachile brevis was significantly associated with the wild type native, ‘Dwarf White’, and ‘Aurora’.

Image 2. A and B: Leafcutter bees cut discs from petals of a cultivar. C: A leafcutter bee carries a petal disc to its nest. D: A leafcutter bee nest in a sunflower stalk. Credits: Svea Bruslind (A), Devon Johnson (B), Mallory Mead (C), Heidi Nordijk (D), © Oregon State University

Although Jen found evidence that the leafcutting bees were significantly associated with two of the three cultivars she included in her study, Mallory documented a very strong preference for the wild-type native over the cultivars, when she documented foraging for nesting material. Because leafcutting bees leave a characteristic crescent cut in petals, Mallory could document foraging for nesting material by counting the number of petal cuts from each plant. Wild type native plants had 3-4X as many petal cuts than cultivars. Even when we controlled for bloom count per plant, the wild type native was significantly preferred over the cultivars.

Image 3: Number of petal cuts by bees on wild-type Farewell-to-spring, and 3 cultivars.

Native Cultivars Are Often Easier to Find and Buy

Given the high abundance and diversity of beneficial insects associated with Farewell-to-spring, as well as its unique association with specialist foragers and petal-cutting bees, we enthusiastically recommend this plant to ecologically-minded gardeners. However, the average gardener shopping for this species is more likely to encounter cultivars than wild-type plants. This is partly because the plethora of Farewell-to-spring cultivars are on the market. In addition to the three included in Jen’s study, gardeners can find ‘Double Azalea’ (pink, purple, red, white flowers), ‘Lilac’ (pink petals with dark red center spots), ‘Pink to Red’ (red petals with light pink edges), ‘White’ (white flowers), ‘Pink’ (light pink flowers with no other markings); and ‘Sugarplum’ (semi-double flowers, light pink with rose-colored center markings, dwarf, somewhat bushy).

As noted earlier, native plants can be difficult to source in the retail marketplace. Offerings may not reflect the regional species pool of plants (Zinnen and Matthews 2022), and in some areas, 77% of the native plants on market shelves are actually hybrids or cultivars (Coombs et al. 2020). However, multiple studies have found that gardeners are willing to pay higher prices for native plants and locally sourced plant materials.

Somewhat unexpectedly, in a recent survey of 719 gardeners (Hayes et al. in preparation), 81% report that they buy their native plants at pop-up plant sales hosted by Soil and Water Conservation Districts, Master Gardener groups, or other non-profits. A comparable percentage of gardeners (78%) said that they buy their native plants at retail plant nurseries. However, given the transient nature of pop-up plant sales, it was surprising to us that they were as or more popular than brick-and-mortar stores for native plant purchases. I think this speaks to the difficulty many gardeners have finding the plants they are seeking, and how non-profit plant sales are filling a market void. It also points to a market opportunity for the nursery industry, in general.

References:

Anderson, A. 2019. Native plant production and marketing. The Digger, April Issue, pp 33-36.

Anderson, A. (2022). Evaluating the Attractiveness of Pacific Northwest Native Plants to Insects and Gardeners [Dissertation submitted in partial fulfillment of Ph.D.] Oregon State University.

Anderson, A. G., Costner, L., Best, L., & Langellotto, G. A. (2022). The bee fauna associated with Pacific Northwest (USA) native plants for gardens. Conservation Science and Practice, 4(10), e12801.

Bennett L. 2019. Examining the gap between interest and understanding of provisioning for bees: A capstone project to support urban bee conservation [Thesis submitted in partial fulfillment of M.N.R.]. Oregon State University.

Coombs, G., Gilchrist, D., & Watson, P. (2020). An assessment of the native and invasive horticultural plants sold in the mid-Atlantic region. Native Plants Journal, 21(1), 74-82.

Hayes, J., Langellotto, G. 2020. Pollinator plant trials: researchers test the value of Willamette Valley natives and nativars. The Digger, October Issue, pp 33-37.

Hayes JJ-M, Bell NCS, Best LR, et al. 2025. Pacific Northwest native plants and native cultivars Part I: Pollinator visitation. Environ. Entomol. https://doi.org/10.1093/ee/nvae126.

Oregon Flora. 2025. Gardening with natives. https://oregonflora.org/garden/index.php, accessed January 29, 2025.

Zinnen, J., Matthews, J. W. 2022. Native species richness of commercial plant vendors in the Midwestern United States. Native Plants Journal, 23 (1) 4-15.

Behind the Scenes of the Portland Bee Guide!

Posted on October 24, 2023 by Nicole Bell

What is the Portland Bee Guide?

This month has seen the release of the Portland Bee Guide! This guide was a collaborative project among many different members of the Garden Ecology Lab, along with numerous others inside and outside Oregon State University. Our goal for the project was relatively simple: create an accessible guide to Portland bees. If you haven’t already, click here to download the Portland Bee Guide. It contains species descriptions of 67 bee species found in Portland, OR, gardens (including the ones seen below!), and the accompanying iNaturalist guide (click here) contains photos and interactive functional trait filters for each species. Read on for bonus content, not included in the bee guide or in the social media campaign we ran to promote the guide earlier in recent weeks.

This blog will also serve as an access point to the social media content, for those not on Instagram or Facebook. The social media campaign contained three sets of posts: one focused on floral resources for bees, another on nesting sites for bees, and the final was a feature of some of the Portland bee-friendly gardeners.

Making the Guide

Most of my time spent on the guide happened in my home, which is my preferred work space (it helps that a cat is included). Specifically, a table on the same back patio where I grew up spending time with my family in the outdoors as I was growing up. When I entered graduate school, the sampling in Portland gardens was already finished—so many people had contributed to this project before I ever knew it existed. The main thing that inspired me to work in science communication was the opportunity to serve as a liaison between the academic sphere and the public sphere. I’ve always enjoyed interacting with people, and was parented by scientists who valued their work in Extension programs.

The back patio, where I spent much of my time this past summer working on the bee guide.

Because so much of my work took place on my computer, far removed from the soil, forage, and buzzing bees of Portland, I knew I wanted to make visiting some of the gardens a priority. This would allow me to have a deeper understanding of the guide itself prior to its release, as well as to take photographs and interview some of the gardeners who hosted diverse bee communities in their backyard. I completed my visits in June 2023, and got a chance to talk with gardeners about their successes, setbacks, motivations, and more. Let’s look at some of these gardens!

Our 3 Featured Gardeners

Pascal: “Small and mighty”

Pascal’s garden is in Northeast Portland. He lives just off a busy street, so his main goal when creating his garden was privacy. I was inspired by Pascal’s eye for design—his garden, to me, was the definition of maximizing space. He has created a layered effect, with winding pathways, designated sections for food crops and ornamental plantings, but everything blended seamlessly. Though I could tell from the road that Pascal’s garden was going to be quite something, while I was inside it felt like I was in on a secret: here I was, in a secluded refuge.

I asked Pascal!

What is the biggest challenge you deal with in your garden? “My biggest challenge is keeping the garden healthy and thriving during dry stretches of weather, which seem to be getting longer each year. I use soaker hoses throughout the garden and run them once a week, but during extreme heat and dry weather over the last few summers, the stress on the plants is obvious. I’m now running them more often, and this year, earlier than in previous years. More water means a bigger water bill, but it’s better than losing established plants to drought. When I do lose plants, I now plant replacements that are native and more drought tolerant.”

What has been your biggest gardening success? “My biggest gardening success has been transitioning this yard, that was basically lawn and a few trees, into a biodiversity hotspot with almost 80 species of plants stuffed into a small space. All those plants now provide a lush green wall that blocks out some of the noise and business of our urban location. They also provide shelter and forage year-round for a variety of birds, insects (including pollinators), a few small mammals and even a lost cat, who we were able to rehome.”

What is your favorite spot in the garden? “My favorite spot in the garden is under the canopy created by a series of overlapping trees that create a cool, shaded area over the lawn. It’s the perfect spot to sit on a hot day and face out towards the surrounding gardens and see all the activity that is going on with birds, bees, and other insects moving around. The yard is still noisy, but sitting under those trees feels peaceful.”

Pascal and my father, Neil (also a retired Community Horticulturist for Oregon State), talking about plants in Pascal’s urban refuge. I love this photo because you can get a feel for the layered effect that this garden has. The variety of foliage textures makes the space feel welcoming, cozy, and vibrant.

Bob: “A bee’s urban paradise”

I visited Bob, along with a fellow Master Gardener, Cathy, at the Multnomah County Master Gardeners Demonstration Garden. This garden is open to the public, and Bob made is clear that visitors are welcome. Visitors are free to come walk around the garden, which is not limited to pollinator-oriented spaces. Other gardeners focus on food crops, ornamental plantings—there’s even a willow tunnel to walk under. The garden is beautiful, and worth a stroll-through if you’re in the area. It was such a joy to talk with both of them—their passion for both pollinators and gardening was tangible, and his interest in learning more about the bees he was seeing in his plot was inspiring.

Bob and Cathy standing next to their sign at the Multnomah County Demonstration Garden. If you’re in the Portland area, take a visit! It’s open to the public, and they were both wonderful to talk to.

The number of active pollinators here was astounding! Many of my now-favorite bee photos came from my visit to Bob’s garden. Male long-horned and leaf-cutter bees snoozing inside California poppy, Agapostemon (“green bees”) on Gaillardia, and bumble bees abounded during my midday visit. Many of those bees are pictured in our social media campaign, which will be included below.

I asked Bob!

What is the biggest challenge you deal with in your garden? “Unwanted plants. However, we have developed management strategies to deal with them. We plant very densely and layer plants vertically; we also tolerate some ‘weeds’.”

What has been your biggest gardening success? “Over time, Master Gardener colleagues—some of whom initially looked askance at what we were doing—have come to appreciate the aesthetic of our plantings. While some still wouldn’t garden the way we do, they now recognize that there’s a method to our madness.”

Where is your favorite spot in the garden? “I enjoy standing at the intersection of the steppingstone pathways, where I feel engulfed by vegetation.”

Sherry: “A suburban oasis”

Sherry is a long-time supporter of the lab, and follower of our research. One of my favorite parts of her garden is her planting of Douglas aster and goldenrod, which she was inspired to plant based on Dr. Aaron Anderson’s research, a past GEL lab member. The plating overlooks the Willamette River. I included this quote in the social media campaign, but I can’t help from including it here too: “Growing together, both receive more pollinator visits than they would if they were growing alone. It’s a testable hypothesis; it’s a question of science, a question of art, and a question of beauty.” – Robin Wall Kimmerer, from Braiding Sweetgrass.

Something I admire about Sherry’s garden is how she incorporates both native plants, and also plants that are important or special to her. It reminds me of my childhood garden growing up, planted and cared for by my parents, both horticulturists. I remember being surrounded by vegetation on our back patio, which was one of the first places I ever experienced the natural world up close.

I asked Sherry!

What is the biggest challenge you deal with in your garden? “Leaving unwanted and unmulched ground for nesting bees is hard for me. Bare ground goes against my nature!”

Sherry has done a wonderful job of incorporating more patches of bare soil into her garden: these spots are perfect for ground-nesting bees!

What has been your biggest gardening success? “A bee garden starring Douglas aster and goldenrod, two natives that tested well in the Garden Ecology Lab research. I added Allium, Emerus, rose, Persicaria, Phlox, Verbascum, and a Vitex for diversity and to extend bloom time.”

Where is your favorite spot in your garden? “I favor areas where there is a place to pause and reflect: an alcove off the driveway affords a scene of raised beds against a coral-colored wall, a bench surrounded by a circle of Phlomis offers expansive views of the pollinator garden, and a second-story deck gives a bird’s eye view of colorful shrubs and perennials below.”

Sherry standing next to the Phlomis in her June garden. This is one of her favorite spots to pause and admire the work she has put into this space. I can see why!

Social media content lives here, too!

Above: the set of slides included in our first post, which focused on floral resources for bees.

Above: the set of slides for our second post, which covered nesting sites for bees.

Above: the third and final post in our social media campaign, featuring Portland gardeners Pascal, Bob, and Sherry!

Thank you to everyone who has taken the time to tune in over the past month. Take some downtime during our rainy Oregon winter to familiarize yourself with the written guide PDF (downloadable here) and the online interactive iNaturalist guide (click here), so you’re ready for all our Portland bees next spring!

Do you have questions about the guide? I am more than happy to chat with you! Feel free to reach out to me at nicolecsbell@gmail.com.

Gardeners Needed for a Native Plant Survey!

Posted on October 9, 2023 by Jen Hayes

Study: Native Plants & Native Cultivars: Understanding Pollinator Preference for Native Plants and their Cultivated Counterparts in the Pacific Northwest

Thank you for your interest our survey! We are done collecting survey responses at this time. If you previously took the survey and have any questions, please direct them to Gail.Langellotto@oregonstate.edu and/or Jen.Hayes@oregonstate.edu.

Research Study Seeking Gardeners in Lane or Linn Counties

Posted on July 28, 2023 by Gail Langellotto

This note comes from our collaborator at the University of Oregon, Dr. Gwynne Mhuireach. Dr. Mhuireach previously worked with our lab and local gardeners to document soil microbial communities, and the extent to which the act of gardening transfers soil microbes to gardeners’ skin ~ thus affecting the skin microbiome!

At the conclusion of the skin microbiome study, many gardeners asked for more information on how gardening affects the gut microbiome. Dr. Mhuireach received USDA funding to conduct a pilot study, to address this question. Gardeners in Linn and Lane Counties are specifically invited to apply.

The deadline to apply to participate in this NEW study is August 15th.

We are seeking healthy adult gardeners to engage in a research study exploring microbiota of fresh fruits and vegetables from gardens and supermarkets, and their potential to influence the gut microbiome. To be eligible, you must be between the ages of 18–45, be fluent in English, live in Lane or Linn County, and have access to a garden that can provide enough fruits and vegetables for the diet intervention. Participants will receive $50 at the beginning of the study, $50 upon completion, and a $75 allowance to purchase supermarket fruits and vegetables.

Study activities: If you participate, you will be asked to undergo two week-long diet intervention periods during which you will eat the USDA-recommended amount of fruits and vegetables. In one period all of the produce should be sourced from your garden and in the other the same produce should be sourced from a supermarket. You will be also asked to pre-plan your meals for the intervention periods, complete a Lifestyle, Health, & Diet Questionnaire, maintain a Daily Fruit & Vegetable Log, collect samples of all the fruits and vegetables you eat, collect stool (fecal) samples, and collect a tapwater sample. The total duration of participation is 24 days, with an expected average time commitment of 20–30 minutes per day.

Potential risks: Participants will be exposed to microorganisms from garden and supermarket produce, however, this exposure occurs during normal daily life. There is also a risk that privacy or confidentiality could be breached, though precautions will be taken to avoid such breaches.

Benefits: There are no direct benefits to participating in this study.

To see if you are eligible, please use this Qualtrics link (https://oregon.qualtrics.com/jfe/form/SV_9Gn0UOtZEbzWEh8) to take a brief screening survey. More information is available at www.gffstudy.com.

A place setting, on top of soil. In place of a plate is a shovel head full of vegetables. — Organic farm to table healthy eating concept on soil background.

We’re Looking for Ecolawns!

Posted on July 20, 2023 by Gail Langellotto

A group of five people are looking at a series of ecolawn study plots, while a female scientist is talking about ecolawns. — Ecolawn research plots at OSU’s Lewis Brown Turfgrass Research Farm in 2019.
Photo: Brooke Edmunds, Oregon State University

What is an ecolawn?

An ecological lawn, or ecolawn, is a reduced input alternative to a conventional mowed grass lawn. While numerous possibilities for an ecolawn exist, they all include multiple low-growing herbaceous plants that work well together and require less mowing, fertilizer and irrigation. In addition to reducing maintenance and resource utilization, they also provide important habitat for pollinators like bees and butterflies.

Help us find examples!

We are looking for examples of beautiful ecolawns throughout western Oregon. A few requirements:

Includes 3 or more different herbaceous broadleaf plants; additional grasses optional
Mutually compatible and ecologically stable when grown together
Installed for 2+ years (Spring 2021 or earlier)
All or most plants less than 1 foot in height
Looks good all year (and most of your neighbors would agree that it looks good )
Needs little to no water to stay green through dry summer months
Little mowing (once per month to once per year)
Little or no fertilizer and no pesticides following installation

We want to find, understand and share your (or your neighbor’s) ecolawn. Ecolawns are part of a more sustainable future for Oregon. If you have a good example, please email 2-3 photos and contact information to Dr. Phil Allen, Visiting Professor in Horticulture at Oregon State University: allephil@oregonstate.edu

Petal-cutting Bees!

Posted on January 27, 2023 by Mallory Mead

A study of leafcutter bees and a PNW native flower, through the lens of iNaturalist.

The Clarkia Project team: Mallory Mead, Jen Hayes, Sarah Erskine, and Ali Filipovic

If you are a subscriber to our blog, you have likely seen our photos and videos of one of our favorite plant-pollinator interactions: the petals of Farewell-to-Spring (Clarkia amoena) being harvested by leafcutter bees!

After observing this eccentric harvest behavior in the research garden, we got curious about the bees behind the petal-nest craft, and how we could study this interaction further.

Leafcutter bee mid-petal-harvest! Photo by Devon Johnson.

Crescent-shaped petal-cuts left behind by leafcutter bees.

iNaturalist is a popular community-supported biodiversity database that the Garden Ecology Lab has been experimenting with in recent years. Jen realized that the leafcutter bees’ distinct crescent-shaped mark are visible in many iNaturalist observations of Clarkia amoena. She wondered how we could use the already sizeable iNaturalist database of Clarkia amoena observations to study the interaction over a wider geographic and chronological scale than that of the research garden. Jen and Gail agreed to mentor me in producing an undergraduate research thesis on this subject.

The study’s objective is to use iNaturalist’s data on Clarkia amoena to see if there is a difference in leafcutter bee usage of Clarkia amoena petals based on whether the flower is a native versus a cultivar type, and whether the flower is found in an urban or non-urban environment.

In this process we have found that iNaturalist is easy for anyone to contribute to, but the information it provides is limited compared to the wealth of contextual information gained when being in the actual, living presence of a specimen. So, to get a greater feel for the intricacies of this flower, I embarked on what we called “Ground-Truthing Field Trips” to check out some Clarkia amoena populations in the “real world”.

I went out during peak pollinator season, following the coordinates of recently posted iNaturalist observations. Each specimen I visited was incredibly different from the next. I found the delicate blossoms in natural areas, the borders of farmland, restoration sites, and gardens.

Data from these trips will not be published in my thesis because the contexts are not exactly comparable, and my sampling was exploratory rather than precise. Nonetheless, I gained contextual insight and inspiration watching diverse pollinator assemblages in beautiful meadows of pink.

Mallory at a meadow restoration site near Corvallis with *Clarkia amoena* and tarweed (*Madia* elegans).

The field trips have helped us more clearly see through the window of iNaturalist and have informed the methodology we use.

For example, I saw examples of hybridization between two species of Clarkia in a seeded restoration site, and cultivar-hybrid escapees in natural areas. It’s been important to navigate identification of cultivars and hybrids in iNaturalist.

In a restoration prairie seeded with two different Clarkia species, pollinators cross-pollinate them, giving rise to sterile hybrids (Lewis & Raven, 1958). Note the malformed stigma and anthers.

Simultaneously, our field crew recorded petal-cutting behavior on the Clarkia amoena natives and nativars at Jen’s research garden this summer. Below are the three cultivars in the garden, and if you look closely you can see “petal-cuts” which we counted and recorded weekly. We will analyze the difference in leafcutter usage between the cultivars and native type.

This hot pink, stripy *Clarkia* doesn’t look like either the native or cultivars we had planted!

Clarkia amoena is an annual that reseeds itself effectively, so last year’s seeds gave rise to this season’s blooms. To our surprise, however, Clarkia amoena of all different colors started popping up in our research plots this Spring! Last season’s bees had combined pollen from the garden’s varieties bringing rise to all sorts of intermediate forms.

Clarkia amoena is prone to hybridization between members of the species or cultivars in the same proximity. These intraspecific hybrids are fertile. We seek to explore how cultivar genetics may be moving into natural populations.

Through the winter, our team is working with the iNaturalist data to quantify leafcutter bee petal usage. We expect to share our results in June 2023, so stick around to hear about our findings!

Work Cited:

Lewis, H., & Raven, P. H. (1958). Rapid Evolution in Clarkia. Society for the Study of Evolution, 12(3), 319–336.

2022 Field Update: Native plants & native cultivars

Posted on December 26, 2022 by Jen Hayes

This summer we completed our third and final field season surveying pollinator visitation to native plants and native cultivars! We will maintain our experimental garden for one additional season, to finish up some plant measurements and data collection missed in our initial three seasons. This post will serve as a 2022 field update in addition to summarizing some of our preliminary results from our field observations!

Study Plants (2020-2022)

*Discontinued in 2021 due to lack of vigor and availability of replacement plants
**Added in 2021 to replace removed plants
*******Discontinued after 2020 due to taxonomic inconsistencies

Scientific Name	Common Name	Plant Type
Achillea millefolium	Yarrow	Native
Achillea millefolium ‘Calistoga’*	Yarrow	Cultivar
Achillea millefolium ‘Salmon Beauty’	Yarrow	Cultivar
Achillea millefolium ‘Moonshine’**	Yarrow	Cultivar
Aquilegia formosa	Western Red Columbine	Native
Aquilegia x ‘XeraTones’		Cultivar (hybrid)
Camassia leichtlinii	Great Camas	Native
Camassia leichtlinii ‘Caerulea Blue Heaven’	Great Camas	Cultivar
Camassia leichtlinii ‘Sacajawea’	Great Camas	Cultivar
Symphyotrichum subspicatum	Douglas’ Aster	Native
S. subspicatum ‘Sauvie Sky’	Douglas’ Aster	Cultivar
S. subspicatum ‘Sauvie Snow’	Douglas’ Aster	Cultivar
Clarkia amoena	Farewell-to-spring	Native
Clarkia amoena ‘Aurora’	Farewell-to-spring	Cultivar
Clarkia amoena ‘Dwarf White’	Farewell-to-spring	Cultivar
Clarkia amoena ‘Scarlet’**	Farewell-to-spring	Cultivar
Eschscholzia californica	California Poppy	Native
E. californica ‘Mikado’	California Poppy	Cultivar
E. californica ‘White’	California Poppy	Cultivar
E. californica ‘Purple Gleam’**	California Poppy	Cultivar
Nemophila menziesii	Baby Blue Eyes	Native (California)
N. menziesii ‘Penny black’	Baby Black Eyes	Cultivar
N. menziesii ‘Snow White’	Baby Blue Eyes	Cultivar
Sidalcea asprella ssp. virgata*******	Rosy checkermallow	Native
Sidalcea malviflora ‘Purpetta’*******		Cultivar
Sidalcea malviflora ‘Party Girl’*******		Cultivar

We conducted 5-minute visual observations on our study plants over three seasons. During these observations, we recorded all insects that interacted with a plant. These interactions included foraging, resting, basking, mating, etc. We recorded insect IDs to morphological group levels, as many bees are hard to identify to species in the field! We were able to identify common bumble bees, honey bees, butterflies, and a few other insects to the species level, but many were identified to groups for ease (e.g. ‘green bees’, ‘black bees’, ‘leafcutter bees’).

Field Season Stats

Year	# Sample Dates	# Collected Pollinators	# Observed Pollinators
2020	28	2159	6238
2021	33	2471	6225
2022	29	~2000	~4700

Number of sampling dates, total number of collected pollinator specimen (via insect vacuum), and cumulative pollinators observed during 5-minute observations for each of our three field seasons.

Is there a difference in native bee visitation to native plants and their cultivars?

Graphs of cumulative and mean foraging native bees from 5-minute observations conducted over three field seasons. Plant Type (y-axis) is abbreviated with a 6 letter code, e.g. “SYMSUB” = *Symphyotrichum subspicatum* = Douglas’ Aster. Natives have a box around each bar, and cultivars can be identified by an underscore followed by 1-2 letters, e.g., SYMSUB_SN = *Symphyotrichum subspicatum* ‘Sauvie Snow’ = a native cultivar of Douglas’ Aster with white petals.

Our initial graphs show a subtle preference for native types by native bees. Douglas’ Aster, California Poppy, Farewell to Spring, and Columbine (4/7) have higher visitation by native bees when looking at cumulative and mean counts. The difference is marginal for Douglas’ Aster, but trends for the other three plants are strong. The remaining three species (Yarrow, Baby Blue Eyes, Camas) are difficult to assess, based on these figures alone.

Across these seven species, we do see differences in visitation between natives (wild types) and native cultivars. Whether these differences are statistically significant, and whether there is a trend across all plant groups, remains to be seen!!!

Subscribe to the Garden Ecology Blog to receive future updates on native-cultivar research and more news from the lab.

I want to recognize my amazing Bee Team this year, as this field season would not have been possible without them! I am grateful for all of their hard work and their success in managing this project while I was away numerous times this season. They are thoughtful, inquisitive, and resourceful students, all of whom would make amazing lab or field technicians upon their graduation this spring! Nicole is not pictured below, but also deserves recognition for all her contributions to this project. Thank you all

Svea working on her ultraviolet photography

Top 10 Oregon Native Plants for Pollinators: WEEK 10!!

Posted on January 24, 2022 by Jen Hayes

The Garden Ecology Lab’s Pollinator Plant PR Campaign Presents….. Douglas Aster!

The Garden Ecology Lab is releasing a series of plant profiles of the top 10 Oregon native plants for pollinators, based on Aaron Anderson’s 2017-2019 field trials of 23 Oregon native plants. We will feature one plant per week for 10 weeks, this is week 10, which marks the end of our 10-week series! Profiles will include photos, planting information, and will highlight common pollinators of each plant.

Melissodes visits Douglas Aster. Photo by Tyler Spofford.

Plant Facts

Scientific Name: Symphyotrichum subspicatum
Life Cycle: Perennial
Growth Habit: Vigorous spreader, spreads through underground rhizomes
Bloom Duration: July-November
Hardiness Zone: 6-9
Special Traits: Drought tolerant, deer resistant
When to plant: Starts can be planted in the spring or early fall.

Pollinator Facts

Douglas aster provides both nectar and pollen to its insect visitors.
Aaron’s research found three species of long-horned bees (Melissodes robustior, M. lupinus, and M. microstictus) and three species of bees from the family Halictidae (Halictus ligatus, Agapostemon texanus angelicus and A. virescens) to be associated with Douglas aster.
Other common visitors to Douglas aster include syrphid flies and northern checkerspot butterflies! Douglas aster may also be a larval host to 8 different month species¹.

Photo by © mandamasprime, some rights reserved (CC-BY-NC).

Douglas Aster‘s Native Range in Oregon

Douglas aster is native to Northwestern Oregon and most of the coast.

Maps and legend acquired from the Oregon Flora Project, with Imagery Sourced from Google. Copyright 2022© TerraMetrics

Douglas Aster as a pollinator plant

Douglas aster is native to Western North American with a range extending from Alaska to California. It has an impressive ability to spread and a high volume of flowers that buzz with pollinator activity throughout its long bloom season. Hosting a high abundance and diversity of bee visitors, Douglas aster is a pollinator plant superstar. It is particularly valuable as a late-season pollinator plant, able to provide both nectar and pollen to its visitors when these resources may otherwise be scarce in the landscape.

People often have strong reactions towards Douglas Aster – they either love it, or find it to be “weedy” in appearance. We hope that this highlight may help some people change their opinions about it! We in the Garden Ecology Lab love Douglas Aster for its abundant blooms in varying shades of purple and for its great capacity for supporting wildlife. In the late summer, we love watching the diversity of pollinators bouncing from one flower to the next! Some common visitors to Douglas Aster that we see at Oak Creek Center for Urban Horticulture include bumblebees, green bees, long-horned bees, small sweat bees, and butterflies, including the woodland skipper (pictured below) and the occasional grey hairstreak (Strymon melinus).

Here, we see a woodland skipper (Ochlodes sylvanoides) foraging from Douglas Aster!

Infographics developed by LeAnn Locher, Aaron Anderson, and Gail Langellotto.

Did you know?

By mid to late summer, Douglas aster is quite the frenzied pollinator feeding ground, making the Oak Creek team’s sampling effort always a bit of a challenge. These photos are from 2 years after these plants were established, so you can see just how full these young plants can get when grown in favorable conditions!

At Oak Creek, we started all of our Douglas Aster plots with 4x 4″ pots, planted in the spring of 2020. As you can see in the photos below, they easily filled up their 1×1 meter beds! If you’re worried about Douglas Aster taking over your garden, consider starting with a single plant and observe it over the season to see how it reacts to your garden environment. Aggressive spreaders can be used to fill spaces such as borders with forest edges or along fences where low maintenance plants are key. If you want to contain your asters, consider planting some in a large pot or in an area where you can easily control the spread of their underground rhizomes. The purple flowers contrast beautifully with other late season natives, such as goldenrod and Madia.

Jen standing next to her Douglas Aster experimental plots. Photo by Tyler Spofford.

Tyler vacuum sampling bees off of a Douglas Aster plot. Photo by Jen Hayes.

Photos from the field

A yellow-faced Bumblebee visits a Douglas Aster flower
A woodland skipper enjoying some nectar
The baby Douglas Aster plants we introduced into the field in 2020
Douglas Aster still blooming strong on October 3, 2020
The native Douglas Aster has beautiful purple rhizomes!
Douglas Aster cultivars are even more vigorous, look at all these new shoots we removed from a neighboring plot!
Douglas Aster 1 year after planting, with last season’s biomass removed
A sweat bee enjoying some pollen!

Thanks for tuning in to the last posting of our Pollinator Plant PR Campaign! We hope you try growing some of these fantastic pollinators plants.

Top 10 Oregon Native Plants for Pollinators: Week 9

Posted on January 17, 2022 by Mallory Mead

The Garden Ecology Lab’s Pollinator Plant PR Campaign Presents….. California Poppy!

The Garden Ecology Lab is releasing a series of plant profiles of the top 10 Oregon native plants for pollinators, based on Aaron Anderson’s 2017-2019 field trials of 23 Oregon native plants. We will feature one plant per week for 10 weeks, this is week 9! Profiles will include photos, planting information, and will highlight common pollinators of each plant.

Plant Facts

Scientific Name: Eschscholzia californica
Life Cycle: Annual/Perennial
Growth Habit: Clumping, sprawling
Bloom Duration: Early Spring to Late Summer depending on seeding date.
Hardiness Zone: 7-10
Special Traits: Drought-tolerant, deer and rabbit resistant.
When to plant: Seed in Fall for a Spring bloom, or seed in Spring for a mid-summer bloom.

Pollinator Facts

California poppy only provides pollen to its insect visitors, but provides it in an abundance!
Aaron’s study found California poppy to be associated with 4 species of sweat bees: Halictus farinosus, H. tripartitus, Lasioglossum dialictus sp. 5, L. olympiae, and a bumblebee: Bombus vosnesenskii.
Other common visitors to California poppy include butterflies, specifically, acmon blue and mormon metalmark.

Sweat bee leaving a California poppy. Photo by Jen Hayes

California Poppy’s Native Range in Oregon

Oregon's populations of California poppy are primarily found in the Willamette Valley and the Klamath Mountains as well as some parts of the Columbia River Gorge and the Coast Range.

Maps and legend acquired from the Oregon Flora Project, with Imagery Sourced from Google. Copyright 2021© TerraMetrics

California poppy as a pollinator plant

California poppy’s range extends from Washington to northwest Baja California and east towards Arizona and southwest New Mexico. A popular flower for roadside plantings, California poppy survives well in average to poor soil that is well-draining. It survives mild-winters as an herbaceous perennial and reseeds itself readily. California poppy is an all-around easy pollinator plant to grow, and growing it pays off, as it attracts an incredible diversity and abundance of bees with its remarkable volumes of pollen.

Infographics developed by LeAnn Locher, Aaron Anderson, and Gail Langellotto.

Did you know?

California poppy’s petals are responsive to light! In the absence of light (at night and on cloudy days) petals spiral around each other and tighten to a close. In the presence of light, cells in the petals expand in response to the plant growth hormone auxin. This mechanism opens the petals allowing pollinators to access the flower’s pollen — although in the field we watch impatient bumblebees force their way into closed California poppy flowers to get to the pollen anyways.

Petals close tight during the night and remain so on overcast days. Photo by iNaturalist user metacom CC some rights reserved

Poppies in various stages of opening and poppy buds enclosed in pinkish-green calyxes. Photo by iNaturalist user Daniel Das C C some rights reserved

Photos from the field

Sweat bee traversing stamen. Photo by Jen Hayes
The underside of a sweat bee with pollen on its abdomen and hind legs. Photo by Jen Hayes
Photo by iNaturalist user baileylemkau CC Some rights reserved.
Jen’s California poppy research plot. Photo by Jen Hayes

Tune in next week for the next edition of our Pollinator Plant PR Campaign.

Top 10 Oregon Native Plants for Pollinators: Week 8

Posted on January 10, 2022 by Jen Hayes

The Garden Ecology Lab’s Pollinator Plant PR Campaign Presents….. Globe Gilia!

The Garden Ecology Lab is releasing a series of plant profiles of the top 10 Oregon native plants for pollinators, based on Aaron Anderson’s 2017-2019 field trials of 23 Oregon native plants. We will feature one plant per week for 10 weeks, this is week 8! Profiles will include photos, planting information, and will highlight common pollinators of each plant.

Plant Facts

Scientific Name: Gilia capitata
Life Cycle: Annual
Growth Habit: Erect, clusters
Bloom Duration: May – June
Hardiness Zone: 7-10
Light requirements: full sun
Special Traits: Drought tolerant, tolerant to various soil types.
When to plant: Seeds can be sewn directly in the fall, or can be stratified indoors over the winter before planting out in the spring.

Pollinator Facts

Globe Gilia provides both nectar and pollen to its insect visitors.
Gilia was found to be associated with the yellow-faced bumble bee, Bombus vosnesenskii in Aaron’s research.
Globe Gilia is also a larval host for at least one moth species, Adela singulella, but possibly four others as well.
In addition to insect visitors, Gilia is can be an occasional nectar source for hummingbirds¹, which love its tubular flowers!

Globe Gilia‘s Native Range in Oregon

Gilia Complex: Distribution of all Oregon Gilia capitata
Blue Field Gilia: Distribution of Gilia capitata ssp. capitata
Blue Field Gilia: Gilia capitata ssp. capitata. Photo (C) Kier Morse, courtesy of Oregon Flora
Pacific Gilia: Distribution of Gilia capitata ssp. pacifica
Pacific Gilia: Gilia capitata ssp. pacifica. Photo (C) iNaturalist user Wyattd.
Dune Gilia: Distribution of Gilia capitata ssp. chamissonis
Dune Gilia: Gilia capitata ssp. chamissonis, photo (C) iNaturalist user sennesand.

There are three subspecies of Gilia capitata in Oregon: Bluefield Gilia (ssp. capitata), Dune Gilia (ssp. chamissonis), and Pacific Gilia (ssp. pacifica). Dune Gilia and Pacific Gilia are considered to be rare plants in California (rare, threated, or endangered, rank 1B).

Distribution maps acquired from Oregon Flora with imagery from Google. Copyright 2022.

Globe Gilia as a pollinator plant

Globe Gilia may have only been associated with a single bee species in Aaron’s native plant research, but it is truly a powerhouse of an annual plant: it supports a highly diverse and abundant community of native bees! Gilia’s globe of flower heads provide pollinators with plenty of foraging spots to choose from, and the dense mass also allows easy access for both small and large pollinators, by acting as a nice landing pad. From their comfortable perch, butterflies and larger-bodied bees can dip their proboscis (tongue) into the nectar-rich blossoms. Smaller bees may need to crawl in to the individual flowers to access the nectaries.

Gilia is a great annual plant option to include in pollinator mixes and in meadows. It’s an easy to care for plant, requiring minimal water during the growing season. It grows up to three feet in height with lovely lavender – dark purple – blue flower heads, lacy foliage, and surprising blue pollen! The flowers contrast wonderfully with many other mid-summer blooms, such as poppies, Oregon sunshine, asters, and Clarkia.

Infographics developed by LeAnn Locher, Aaron Anderson, and Gail Langellotto.

Abundance Calculations. Bee abundance was calculated using estimated marginal means of bee visitation to each of our study plants from 5-minute observations conducted from Aaron’s 2017-2019 field seasons. Estimated marginal means (EM Means) were assigned to categorical values and averaged across years to yield the following categories: 0% = Very Low =EM mean below 0.49; 25% = Low = EM mean of 0.50 to 0.99; 50% = Moderate = EM mean of 1 to 1.49; 75% = High = EM mean of 1.50 to 1.99; and 100% = Very high = EM mean above 2.0.

Diversity Calculations. Bee diversity was based on the total sum of species collected on each of our study plants from 2017 to 2019. A Chao 2 Estimator was used to estimate total expected species richness for each plant; Chao 2 estimates were then used to create categorical values, as follows: 0% = Very Low = 9.99 or lower; 25% = Low = 10 to 14.99; 50% = Moderate = 15 to 19.99; 75% = High = 20 to 24.99; 100% = Very high = 25 or higher.

Did you know?

When you think about pollen, one color tends to come to mind: yellow. Perhaps you conjure up an image of a bumblebee in a field of clover, weighed down by some giant orange-toned pollen baskets as well. Many of us might stop there, and conclude that pollen must be either yellow or orange, as those are the predominant pollen colors we see in the plant world. The absolutely exciting news is that, like flower colors, pollen also comes in a rainbow of colors. Globe Gilia, for example, has pollen that comes in shades of blue!

A spotlight on pollen colors

As some of you may remember from my (Jen’s) 2021 field update, last summer, a few of us from the Garden Ecology lab had the wonderful opportunity to visit Jasna Guy and Lincoln Best’s exhibit ‘In Time’s Humm’ at the High Desert Museum in Bend. Part of this display was a pollen color study, showing Jasna’s recreations of pollen colors using pastels. We saw pollen in shades of yellows, oranges, red, pink, purple, white, and even green. Color can truly be found anywhere if you look closely enough! Perhaps it should be no surprise then, that even nectar may come in various colors, too… If you’re excited about pollen colors like we are, you might see if your local library has a copy of this book, and you might enjoy looking at pollen colors through the seasons, put together by the North Shropshire Beekeepers’ Association.

Now back to Globe Gilia: Photos from the field

Blue Field Gilia: Gilia capitata ssp. capitata. Photo (C) Kier Morse, courtesy of Oregon Flora
Dune Gilia: Gilia capitata ssp. chamissonis, photo (C) iNaturalist user sennesand.
Pacific Gilia: Gilia capitata ssp. pacifica. Photo (C) iNaturalist user Wyattd.

Tune in next week for the next edition of our Pollinator Plant PR Campaign.

Garden Ecology Lab

Socio-ecological research in urban and suburban garden systems

Tag Archives: research

An Update on Native Plant Studies from The Garden Ecology Lab at Oregon State University

Behind the Scenes of the Portland Bee Guide!

Gardeners Needed for a Native Plant Survey!

Research Study Seeking Gardeners in Lane or Linn Counties

We’re Looking for Ecolawns!

Petal-cutting Bees!

2022 Field Update: Native plants & native cultivars

Study Plants (2020-2022)

Field Season Stats

Is there a difference in native bee visitation to native plants and their cultivars?

Subscribe to the Garden Ecology Blog to receive future updates on native-cultivar research and more news from the lab.

Top 10 Oregon Native Plants for Pollinators: WEEK 10!!

Douglas Aster‘s Native Range in Oregon

Did you know?

Photos from the field

Top 10 Oregon Native Plants for Pollinators: Week 9

California Poppy’s Native Range in Oregon

Did you know?

Photos from the field

Top 10 Oregon Native Plants for Pollinators: Week 8

Globe Gilia‘s Native Range in Oregon

Did you know?

Now back to Globe Gilia: Photos from the field