About Gail Langellotto

I'm a Professor in the Department of Horticulture at Oregon State University, where I also coordinate the statewide Master Gardener Program.

Isabella Messer has been a member of the Garden Ecology Lab for more than two years, where she primarily assists with the garden pollinators study, but will is also developing her own research project. Her independent research project will look at bee visitation to some of the plants we are studying in controlled research trials, when these same plants are in a mixed garden setting. Controlled research trials are important, because they let us document the attractiveness of plants to bees, in a setting where study plants are not competing with other plants for pollinators. Controlled research trials are also valuable, because they let  researchers have better control over environmental conditions, such as irrigation. Isabella is going to see whether and how bee visits on plants in a garden context is different than what Aaron is documenting in his controlled research trials. This will be one of the first, if not the first time, that we will have direct and contemporaneous measures of bee visits on focal plants in each situation: in a research field, and in a garden.

In addition to her work in the lab, Isabella is also a member of the ‘Research Retinue’: a group of Oregon State University undergraduates, who review and discuss papers on the PolliNation Podcast.

In this episode, the retinue discusses two papers that look at the impact of a common herbicide (glyphosate) on bees, via indirect impacts of glyphosate on the microbiome (bacterial community) that can be found in honey bee guts.

The paper that they discuss is linked, below:


In case you missed the webinar on our garden bee research, I’ve embedded the video, below. The entire webinar is about an hour.

And, make sure to mark your calendars for Monday, October 22nd at 11am PST. Aaron Anderson will be presenting a FIRST LOOK webinar on his research on native plant-pollinator associations. Visit the hypertexted link, above, to register for this FREE webinar.

Aaron was sharing some of his latest data with me, just this past week. His data, collected at replicated field plots in Aurora, Oregon, echoes what we’ve seen in home garden sites around Oregon: for native bees, Douglas Aster was a top performer.

Lauren Bennett, a Master’s student at OSU, is doing her capstone project on pollinators She has a short survey (10-15 minutes) on pollinators and pollinator plants.

If you could spare a few moments of your time, we would appreciate your participation in this study. More information this study can be accessed, by following the link, below.


FYI ~ this study was deemed ‘quality improvement / assessment’ and not ‘scholarly and journalistic’ by the OSU IRB. Thus, we do not need or have IRB oversight for this study.


In 2017 and 2018, Aaron and Lucas took weekly counts of bees on their native plant plots. Aaron has summarized the data for 2017 (below) according to bee morpho-type. The morphotype categories are the same general categories that have been used by other researchers: bumblebee, honey bee, green bee, small bee, and big bee. These major bee categories are fairly easy to distinguish from one another in the field. Although, Aaron and I talked quite a bit about whether or not we should combine big bees and small bees into a new category: other bees. When does a small bee become a big bee? We had a general sense that a large Megachile rotundata would be a big bee, and a small Ceratina sp. would be a small bee. But, what about a smaller Megachile species? Is that big bee or a small bee? There is no clear answer.

Aaron and Lucas kept records of big bees vs small bees, as best as they could, but in the end, we might collapse all of that data into an ‘other bee’ category.Aaron recently surveyed gardeners, to ask their opinion on the aesthetics of his study plants. A quick look at the results suggests that gardeners and bees might be attracted to different flowering plants. While Gilia capitata was the most visited plant in Aaron’s study plots, it was ranked 6th most attractive (out of 27 plants) by gardeners. The story gets worse for Madia elegans (2nd with bees, 20th with gardeners), Aster subspicatus (3rd with bees, 14th with gardeners), and Solidago candensis (4th with bees, 23rd with gardeners).

Could it be that bees and gardeners are truly attracted to different types of flowering plants? Or could it be that if gardeners knew about the benefits of these Willamette Valley natives, that they might see a new kind of beauty in these plants?


We are so lucky that Lincoln Best has been in Oregon, supporting the work of the Oregon Bee Atlas. Linc was kind enough to take a look at Aaron’s bees, before going back to Canada. Aaron is currently taking a bit of time off, following his wedding this past weekend (Congratulations Aaron and Maura!). In everyone’s absence, I’m chomping at the bit to see what bees were identified from Aaron’s study of Willamette Valley native plants. So ~ for your reading pleasure, here is a preliminary list of bees collected from Aaron’s plant plots.

Aaron and Lucas in the native plant study site. You can see the 1m by 1 m plot in the foreground by Aaron, a second one near Lucas, and a few more in the distance.

A few things to note about this list:

  1. I give no mention of abundance of each bee species. Some specimens were caught many, many times off of a flowering plant species. Others were rare, and only caught once.
  2. This list is not all-inclusive. It’s Labor Day. I’m working. I got excited about the bees, and wanted to share. But, I am not carefully going through every small label.
  3. Some bees were only found on one or two flowering plant species ~ even though Aaron’s plots are all in the same 3 acre field (1X1m plots, with each plot separated from every other plot by 6 m).
  4. Yellow-faced bumblebees were collected off of most plants ~ so I am not listing them, below. I also did not look at the honey-bee plant associations.
  5. Linc dissected male genitalia (yes ~ that is how you need to ID some bees to species), and found FOUR Bombus calignosus (all associated with lavender)~ a vulnerable species on the IUCN Red List.
  6. We also have Bombus fervidus, another species on the IUCN Red List (Vulnerable) on lavender, Salvia, and Gilia.

I’ll leave it to Aaron to make a rigorous accounting of bee-flower associations. But for now . . . on this holiday weekend, I was too excited to not take a peek and share initial findings with all o fyou.

Nepeta (non-native comparitor)

Oregano (non-native comparitor)

Salvia (non-native comparitor)

Lavender (non-native comparitor)

Phacelia (native)

Clarkia (native)

Goldenrod (native)

California Poppy (native)

Doug Aster (native)

Oregon Iris (native)

Gilia capitata (native)

Oregon Sunshine

Madia (native)

Sidalcia (native)

Yarrow (native)

Pearly Everlasting (native)

If you are interested in hearing more about our research, please consider sitting in on one of the upcoming webinars we are presenting, as part of the Advanced Training Series for Master Gardeners, organized by OSU Extension Faculty Member, Brooke Edmunds. Gail will be speaking on August 30th, about garden bees. Aaron will be speaking on October 22 on his native plant research. There is also a presentation in November by Melodie Putnam (not in our lab group ~ but a great speaker) on plant galls.

Webinars qualify for Master Gardener continuing education units in Oregon. The webinars are free, but you must pre-register. After the presentations, all webinar recordings are posted on Brooke’s YouTube channel.

More details, and link to the registration page, can be found, below.

Thursday 8/30 at 11am PT

The latest research on bees in the garden: an update from the OSU Garden Ecology Lab.

Speaker: Dr. Gail Langellotto (OSU)


Monday 10/22 at 11am PT

‘First Look’: OSU Research on Native Plants in the PNW Garden

Speaker: Aaron Anderson (OSU graduate student)


Monday 11/19 at 11am PT

The Weird and Wonderful World of Plant Galls

Melodie Putnam (OSU Plant Clinic)


Missed a webinar? 

Catch up with the 2018 series here: https://tinyurl.com/yczwxjvr (opens in YouTube)

It has been a busy summer in the Garden Ecology Lab!

  • Mykl Nelson successfully defended his thesis on urban garden soils, and graduated with a M.S. in Horticulture this past June.
  • Gail, Aaron, and Mykl all shared their research results with Master Gardeners, at the recent Growing Gardeners conference.
  • Aaron continues his fieldwork, documenting the attractiveness of several Willamette Valley native plants to pollinators. You can find his full list of plants here.
  • Aaron launched the survey part of his research, to document the attractiveness of these same plants to gardeners. If you would like to participate, you can find our recruitment letter, here.
  • Gail and Isabella continue to sample insects on a monthly basis, from 24 Portland area gardens. Our July sample has been pushed to the week of July 30th, because Gail was invited to serve as a panelist on a USDA grant panel. Sampling takes four long days ~ made all the more difficult by Portland’s heat wave. But, sampling during the heat wave will be interesting. Do garden habitats become even more important to bees, when the heat dries up forage in natural and wild habitats? We shall see.
  • Bees from our 2017 sampling effort have been pinned, labelled, and sent to the American Museum of Natural History for expert identification. Thank you to the Oregon Master Gardener Association for a $500 grant to help pay for the expert bee identification.

Today, I’m packing field supplies and clothes for the July 30-August 2nd garden bee sampling effort. It seemed like a good time to provide an update on our garden soils work. I wrote this article for the Hardy Plant Society of Oregon quarterly magazine. I thought that others who are interested in garden ecology might be interested in seeing an update on this work. We are currently working on a manuscript of Mykl’s research, for submission to the journal Urban Ecosystems. In the meantime, some of the highlights can be found below.


Despite the popularity of urban agriculture, we know virtually nothing about urban agricultural soils, including residential vegetable gardens. We thus studied urban garden soils to get a sense of the characteristics of residential-scale, urban agricultural soils in western Oregon. Last year, we took soil samples from 27 vegetable gardens in Corvallis and Portland, and tested for differences between garden sites based upon bed-type (e.g. raised beds versus in-ground beds). All gardens were managed by certified Extension Master Gardeners.

If you have taken a Master Gardener soils class, perhaps you have heard the soil management mantra ‘just add organic matter!’. This mantra comes from the idea that adding more organic matter (OM) can improve soil tilth and nutrition. However, this mantra was derived from research in large-scale farming systems, where farmers often struggle to raise their soil OM by even 1%, across tens or hundreds of acres of crop production.

We found that nearly every garden that we sampled had an excess of OM (Table 1). Soil management guidelines suggest that farmers should aim for 3-6% soil OM. Across all of our garden study sites, vegetable garden soils were on average 13% OM, by volume. Raised beds were significantly over-enriched in organic matter (15% OM, on average), compared to in-ground beds (10% OM, on average). To put it another way, Master Gardener-tended vegetable gardens were over-enriched in OM by 2-5 times the recommended level!

This excess in organic matter likely contributed to excessive levels of other soil parameters. For example, most garden study sites were above recommended levels for electrical conductivity (a measure of soil ‘salts’). All gardens were above recommended levels for sulfur (S), phosphorus (P), calcium (Ca), and magnesium (Mg) (Table 1). Only nitrogen (N), potassium (K), and boron (B) were generally within recommended levels (Table 1).

Table 1. Percent of garden study sites that were within, above, and below recommended ranges for various soil parameters. OM: organic matter. EC: electrical conductivity. N: nitrogen. S: sulfur. P: phosphorus. K: potassium. Ca: calcium. Mg: magnesium. B: boron.

Soil Parameter Percent of Garden Study Sites
Within Recommended Range Above Recommended range Below Recommended Range
OM 6% 94% 0%
EC 18% 82% 0%
N 70% 30% 0%
S 0% 100% 0%
P 0% 100% 0%
K 73% 24% 3%
Ca 0% 100% 0%
Mg 0% 100% 0%
B 42% 3% 55%

The excessive organic matter in residential-scale garden soils makes sense, when considered in the context of garden size. In small garden plots, gardeners can easily over-apply products which have been recommended for successful, large-scale, agricultural production. It is easy to imagine that the over-abundance of organic matter in soils results from large amounts of compost added to a relatively small area.

Our results point to the importance of conducting periodic soil tests in garden soils. Instead of ‘just adding organic matter’, gardeners need to understand where they are starting from, before adding amendments and fertilizers to their soil. Apply focused applications of specific nutrients (such as boron or nitrogen) to correct nutrient deficiencies, as needed, while avoiding additions of nutrients that are at relatively high levels. For example, nitrogen is extremely mobile in soils, while phosphorus tends to build up over time. Adding focused applications of synthetic (15-0-0) or organic nitrogen (in the form of feather meal) can help meet crop needs without providing excessive amounts of phosphorus, over time. Gardeners who annually apply organic matter to their soils, without the benefit of a soil test, may be unintentionally adding too much phosphorus to their soils. Soils with excessive micronutrients may hinder plant growth. Soils with excessive phosphorus might contribute to water quality issues in their watershed. Excessive phosphorus also harms or kill beneficial mycorrhizal fungi.

Our paper on the potential for bee movements between gardens and urban/peri-urban agriculture has been published in a special issue on Agroecology in the City, in the journal Sustainability.

Langellotto, G.A.; Melathopoulos, A.; Messer, I.; Anderson, A.; McClintock, N.; Costner, L. Garden Pollinators and the Potential for Ecosystem Service Flow to Urban and Peri-Urban Agriculture.Sustainability 2018, 10, 2047.

In this paper, we estimated how far the bees we collected from our Garden Pollinators Study could move between gardens and pollination-dependent cropland. We found that when pollination-dependent crops (commercial-scale or residential-scale) are nearby, 30–50% of the garden bee community could potentially provide pollination services to adjacent crops.

But, we currently know so little about bee movements in complex landscapes ~ if and how bees move across roads or through gardens embedded in housing developments. This question will be a focus of our future work.

Some of the bees collected from our 2017 Garden Pollinators study.
Western Columbine
California poppy
Oregon Iris












Over the past year, I have have given many presentations that highlighted the high bee activity at ‘site 51’; a garden that is fairly small (0.1 acre) and in a heavily developed area of East Portland. Despite its size and location, ‘site 51’ had the second highest number of bees from our 2017 collections. I suspect bee diversity will also be high at site 51.

This garden is managed by someone who is an avid Xerces Society member. He gardens specifically for pollinators, and it shows! His garden is a true testament to the idea that ‘if you plant it, they will come’.

So what plants are in this garden? Our preliminary plant list (from a brief 2017 survey) can be found below. I will add Latin names, when I have a moment. For now, I hope that the common name list might introduce you to a new plant or two that might work well in your own garden.

Several of the plants in this garden are native to the Willamette Valley, and are included in Aaron Anderson’s study of native plants. The photos in this post are from Aaron’s field research.





  • Iris
  • Nodding onion
  • Yarrow
  • Fescue
  • Milkweed
  • Woodland strawberry
  • Goldenrod
  • Phacelia
  • Borage
  • Douglas Aster
  • Lupine
  • Daisy
  • Mallow
  • Dogwood
  • California poppy
  • Columbine
  • Meadow foam
  • Yellow eyed grass
  • Cinquefoil
  • Blue eyed grass
  • Currant
  • Crabapple
  • Blue elderberry
  • Anise hyssop
  • Coreopsis
  • Spirea
  • Mock orange
  • Serviceberry
  • Trillium
  • Coneflower
  • Snowberry
  • Oregon grape
  • Shore pine
  • Maple
  • Pearly everlasting
  • Globe thistle