By Margaret Bayne, OSU Extension Service Staff-retired, OSU Master

Asian giant hornet being held between a thumb and forefinger.
Asian giant hornet. Photo: Washington Department of Agriculture

Beneficial wasp found in Asian giant hornet hunt. (Calvin Bratt, Lynden Tribune)

WATCH!- A Zoom presentation with Dr. Linda Chalker-Scott on Arboricultural Myths. (State of Missouri)

New Study Illuminates Dung Beetles’ Attraction to Death. (By Ed Ricciuti, Entomology Today)

The Dirt on Rock Dust. (Dr. Linda Chalker-Scott, Garden Professors blog)

VIDEO: Introduction to Lichen: Growth Forms, Reproduction, and Value. (Microcosmic via youtube)

Silencing the alarm- An enzyme in the saliva of certain insects prevents their food plants from warning neighboring plants of an attack. (Sara LaJeunesse Penn State News)

Why seasonal climate forecasts aren’t always accurate. (Pam Knox, The Garden Professors)

Paleontologists discover new insect group after solving 150-year-old mystery. (Simon Fraser University,

VIDEO:  Bypass vs. anvil pruners. (Oklahoma Gardening via Youtube)

Cambridge moonflower: Wait over for ‘UK’s first’ bloom. (BBC)

Monarch butterfly.
Monarch butterfly. Photo: Oregon State University

Monarch Winter 2020–21 Population Numbers Released. (Susan Day, University of Wisconsin-Madison Arboretum)

WATCH: I Cannot Tell a Lie But Cherry Trees Do Die. (Jay Pschdeit, OSU via Youtube)

Scientists discover attacking fungi that show promise against emerald ash borer. (University of Minnesota, via Phys Org)

Compost in Seed Starting Mix: Recipe for Success…. or Failure? (John Porter, The Garden Professors)

To Fruit or Not to Fruit – The Story of Mast Seeding (Awkward Botany)

January warm spells, March freezes: How plants manage the shift from winter to spring (Richard B. Primack, Boston University via The Conversation)

Red rose bloom.

The contrarian rosarian–debunking rose mythology. (Jim Downer, The Garden Professors)

Catnip repels insects. Scientists may have finally found out how.  The plant triggers a receptor that, in other animals, senses pain and itch. (Erin Garcia de Jesus, Science News)

Cold Comfort  (How Bees survive cold temperatures) (Jon Zawislak, U of Arkansas Extension)

Parasitic plants conspire to keep hosts alive-Mistletoe sends treemail.(Jules Berstein, UC Riverside)

By Margaret Bayne, OSU Extension Service Staff-retired, OSU Master

Doug fir beetle
Doug fir beetle. Photo: LSU Agriculture Center

Pheromone treatment puts up the “No Vacancy” sign for Douglas-Fir Beetles. (Darrell Ross,

Amazing root drawings! (Wageningen University-Image Collection)

Watch the video:  Scientists are discovering new species in the ancient canopies of Canada’s tallest trees.  “On BC’s coast, giant trees have been fed by rain for over 700 years and are home to an incredible micro-world.” (Wild Canadian Weather,

Rhododendrons as thermometers. Did you know that some rhododendrons can act as a living thermometer, showing you just how cold it is by the curl of their leaves?” (Melissa Reckner,

The Mystery of Mistletoe’s Missing Genes.  Mistletoes have all but shut down the powerhouses of their cells. Scientists are still trying to understand the plants’ unorthodox survival strategy.” (Christie Wilcox,

Microscopic wrinkles in leaves ward off insects.  “Researchers identify a new insect-defense mechanism.” (Monique Brouillette,

Beepocalypse myth handbook: Assessing claims of pollinator collapse. (Jon Entine,

7 vegetable seed packets, fanned out on wood table.
Seed packets. Photo: OSU

Learn the terms on seed packets to make the right selection. (Kym Pokorny, OSU; via Nichole Sanchez, OSU)

Houseplant Hubub: The rage about variegation. (John Porter,

Gardening with Native Plants book inspires perennial passions (Linda Chalker-Scott). (WSU)

Insects in flight-11 incredible species in SLOW MOTION-Watch!  “Takeoff and flight sequences of insects spanning 5 different taxonomic orders captured at 3,200 fps!” (Ant Lab, via Youtube)

The bumble bees of the Oregon Bee Atlas.  Watch the video! (Lincoln Best, via Youtube)

Stickiness is a weapon some plants use to fend off hungry insects. (Eric Lopresti, the

Natural wonder: Wing ‘clap’ solves mystery of butterfly flight. (Matt McGrath,

Extension foresters note trend in redwood plantings, plan needs assessment. (Alicia Christiansen, OSU Extension)

Adult spotted lanternfly, sitting on a thumb
Adult spotted lanternfly. Photo: University of Maryland

Five things to know about: Spotted Lanternfly – Oregon IPM Center.  See the video. (Christ Hedstrom, OSU via Youtube)

Natter’s Notes

Jean R. Natter, OSU Extension Service Master Gardener

Once again, the annual Gardeners’ Itch is surging. That’s in spite of the mid-February snow storm that likely afforded one last browse through catalogs, or possibly created a faint cloud of apprehension as you wondered why you bought so many seeds.

Start your project with new containers or thoroughly wash used ones. Just about anything will do as long as it’s at least two inches deep and has drainholes. Plastic containers are a good choice as they slow moisture loss. Consider multi-celled propagation trays; 6-packs you’ve saved from previous years; individual small pots; or use 4- or 5-inch pots as community pans, each one with a different kind of seed.

If you’ll use individual peat pellets, pre-soak well prior to seeding. Then set them side-by-side, one pellet touching the next, thereby increasing moisture retention a bit. After the seeds sprout and begin to develop roots, the pellets will dry rapidly. You might consider a multi-cell tray with individual units the perfect size to hold just one pellet.

The method using individual peat pots is similar. Pre-soak the pots, fill with seeding mix, plant the seeds, then water to settle the mix. But when you transplant to the garden, strip off the peat pot to allow the roots unhindered access to the garden soil.

Fill your containers with a sterile, fine textured growing medium. Do it the easy way with a commercially-packaged seed-starting mix because they’re formulated to drain well in shallow pots. A bonus: The mix is sterile, that is, as long as you don’t set the filled pots on the ground.

Instead of scooping potting mix to fill the pots, use a professional trick to ensure the media remains light and airy, two qualities which guarantee good-sized air spaces that, in turn, allow excellent drainage.

To do so:

a. Set your containers in a group, the sides touching each other.

b. Slightly moisten the media: Add hot water and toss gently to combine, until the media is barely moist throughout.

c. Pour the barely moist media into the containers.

d. Level off excess media with the side of your hand. 

e. Pick up each container and gently tap it onto a hard surface 3 times from a height of 4 inches.

f. Lightly tamp the surface of the media in each container, just enough to level the surface.  (An excellent “tamping tool” is the bottom of another container that matches the available surface area.)

Sow your seeds on the surface of the mix.  Drop one or two seeds onto the surface of each of the smallest units.  If you’re using 4-inch pots, sparsely sprinkle about 20 seeds over the surface. With still larger containers such as a nursery flat, first create shallow rows, then seed. 

Cover the seeds with moist media, the depth to match the diameter of the seed.  Large seeds – such as beans, corn, radish, and squash – are best sown directly into the garden but, for these, wait until the soil is warm enough for rapid germination. Corn and basil planted early will fail.

Water each container thoroughly by setting it in water. Remove when the surface glistens with moisture, allow to drain, and set in a bright, moderately warm place. Alternately, group the pots in a nursery flat and use a gentle spray, moving it back and forth, to thoroughly moisten the media.

Create a mini-greenhouse, of sorts, for your seeds by slipping its pot into a clear container of some sort.  Match the “greenhouse” to the size of your project.  Use what you have at hand, perhaps a clear plastic bag which rests on bamboo sticks to allow head room; or clear plastic storage boxes such as those for shoes and sweaters.

Set the ‘greenhouse’ in a warm but not sunny place. If needed, lift the cover briefly to vent excess moisture that accumulates on the insider.

Spindly seedlings result due to inadequate light at a window, (Client image; March 2017)

Seedlings require bright light! As soon as the seeds sprout, the main challenge is to provide enough light to develop sturdy seedlings.  Sunny windowsills rarely provide adequate bright light for seedlings.

Some folks use a commercial light stand but you can substitute a 2-tube fluorescent fixture suspended 2 inches above a workbench holding the plants. Suspend the fixture on chain so that you can adjust the height as the plants grow. My old-school strategy of one cool white and one warm white tube works well. The plantlets will thrive with 16 hours of light a day.

Seedlings will also benefit from a slightly lower temperature at this stage. On average, daytime temps of 65 to 70°F and nighttime temps of 55 to 60°F are adequate. Then, too, if seedling roots dry out, they die! Watering from the bottom is a gentle method, but dump the excess within 20 minutes.

Seedlings also require fertilizer! Begin fertilizing when the cotyledons ( seedling leaves) are flat out. Use fertilizer-enriched water at half-strength for every other irrigation. And always transplant seedlings, either to a larger pot or to the garden, when the first set of true leaves expand.

Always transplant seedlings when the first set of true leaves expand. But recall that you’ll need to harden off the seedlings prior to planting outdoors. Hardening off means to prepare tender, indoor-grown plants for a harsher life outdoors. (See “Sustainable Gardening.”)

And finally, be aware of the potentially unhappy side of gardening: Herbicide carryover in manure compost. And that’s true whatever the source, free or commercial. I recently responded to an Ask Extension inquiry from a gardener whose vegetables were affected during 2020. (See resource list for online links.)


One of the most delightful things about a garden is the anticipation it provides.

W.E. Johns

These are hope filled times as we eagerly anticipate better days ahead. Gardening certainly gives us solace during such challenging times, and until we are able to resume in-person volunteer activities, the OSU Master Gardener program has a rich variety of continuing education opportunities to engage a wide-array of interests. We hope you will partake and enjoy!


Our state-wide ‘Elevated Skills’ Master Gardener training has launched, but you still have time to take advantage of this wide range of skills building classes which aim to enrich and support Master Gardeners.  This focused training, being taught by OSU Extension staff, has been created to inspire current OSU Master Gardeners (including the class of 2020).

‘OSU Landscape Plant Database’, ‘Superpower Your Education Garden’, ‘Community Science and the Master Gardener Program’, and ‘iNaturalist for Master Gardener Volunteers’ are just a few of the many offerings created to empower and elevate Master Gardeners as community educators. See the entire course line-up, and register HERE.

Note: The metro area MG program is using a different online tool for our MG Helpline clinic and is not using the ECCO tool being highlighted in the “Learning How to Use the Extension Client Contact Online (ECCO) Tool in Plant Clinic” course.

Level Up

OSU Master Gardeners and the gardening public can ‘Level Up’ in a new series for experienced gardeners, with presentations by OSU horticulture experts. Take your gardening knowledge to a new level with timely topics from gardening in a changing climate to techniques to extend your season.

Sessions are filling fast, so if you are interested in the class, be sure to sign-up when the class opens for registration. It will be a rolling registration for the classes throughout the year.

This month’s presentation Tuesday, February 9, 3pm, which focuses on ‘Multifunctional Hedgerows’ has filled – however the presentation will be live streamed on the OSU Master Gardener Facebook page and a recording of the presentation will be posted on the Level Up Series website a few days after the presentation.

Preview and register for the Level Up Series classes, and view recordings of past presentations HERE.

The Culture of Gardening

Come spring, Master Gardeners can participate in ‘The Culture of Gardening’. Explore what gardening means to different people and groups, and how to grow and use plants from a variety of cultures. This new series of blog posts and talks will debut in late spring 2021, with a keynote address by horticulturist Abra Lee on the history of African American gardens and gardeners. The series kicks off on May 18th. Details to come.

Grow Your Own Microgreens – Grow Along

Many Master Gardeners delighted in taking part in the Grow Your Own Microgreens – Grow Along Workshop, at the beginning of the year. During these ‘physically distant’ times it was great to connect with fellow gardeners online and to concentrate on a project that nurtured our gardener’s spirits and added a nutritious boost to our plates.

For those who missed growing along for the first session or had such great fun and want others to share in the adventure, Grow Your Own Microgreens – Grow Along Workshop will reprise February 15 through March 1.

See the details and register HERE. This 15 day workshop is free and everyone is welcome. Please share with fellow gardeners or someone who is wanting to grow something for the first time. Grab some friends to sign-up together and share the excitement as your greens sprout and grow. This is a great first time gardening project for families with kiddos too!

Grow this! Master Gardener Challenge

Food Hero and Master Gardeners are collaborating on the 2021 Grow This! Oregon Garden Challenge. The second year of the Grow This! Oregon Garden Challenge, is much bigger than last year’s Challenge! This year we are looking to sign up 8,000 gardeners to grow vegetable and flowers and need your help!

We need your help to grow along and share your expert advice with these gardeners. Please consider signing up to participate as a Grow This! Champion. Your growing tips, comments, challenges and stories will be shared on our social media platforms and in monthly update emails to beginning gardeners as a way to build a growing community across the state.

Master Gardener volunteers are invited to participate, and apply to be a Grow This! Champion. Note: we are looking to include Master Gardeners from across the state and may need to limit participation if demand exceeds seed supply.

A Grow This! Champion:

  1. Must be a current Oregon Master Gardener volunteer (includes class of 2020) or Master Gardeners representing a county demonstration/educational garden.
  2. Will need to apply for the Grow This! Champion program by midnight February 19 (we are looking to include Master Gardeners from across the state and may need to limit participation if demand exceeds the seed supply).
  3. Will receive one crop seed packet and one flower seed packet.
    (Type and variety will be selected at random.) Specifics about obtaining your seeds will be sent by email.
  4. Must agree to give feedback on your growing process and results
    at least once—but as often as you want—during the Challenge.
    Feedback could include suggestions, comments, challenges and
    solutions, stories, photos, drawings or videos that we can share
    with others (with or without your name). These can be emailed to or shared on social media adding the
    following text to any post: @BeAFoodHero and #mastergardener.
    All feedback is WELCOME.
  5. Can count your active time spent on this project as Master Gardener
    ‘Program’ volunteer hours.

Email or or leave a voice message at 541-737-1017.

Learn more about the challenge here:

Mini-college goes online!

Save the date! as the Oregon Master Gardener Association takes it’s annual ‘Mini College’, garden-education focused, conference online, July 16 and 17, 2021. This is an opportunity to learn from a wide-range of horticultural experts from the comfort of home. Registration opens in March. Watch for details when the website goes live at

By Margaret Bayne, OSU Extension Service Staff-retired, OSU Master

Caterpillars mimic leaves or offer rewards for protection by ants.  “Study reveals different forms of interaction between insect groups: some caterpillar species have bodies covered with molecules identical to those of the plants they inhabit and are ‘invisible’ to ants.” (

Clod of soil
Clod of soil. Photo: Rachel Werling

Soil: The dirty secrets of a living landscape. (Gordon Jones, Scott Goode, OSU; EM 9304)

What food and gardens trends are predicted for 2021? (Samantha Murray, US/IFAS)

Move over murder hornets:  There’s a new bug in town- at it’s coming for your lawn. (Sandi Doughton, Seattle Times)

Catching hope: Possible ally in fight against harmful fruit fly discovered in Asian giant hornet trap (Karla Salp,WSDA)

Extremely rare, one-of-a-kind flower found in Maui’s rugged mountains. (Mark Price, Sacramento Bee)

This drone sniffs out odors with a real moth antenna. “Researchers slap a living antenna on a drone to give the machine an insanely keen sense of smell. Ladies and gentlemen, meet the ‘Smellicopter.’” (Matt Simon, Wired)

Trips on salal leaves
Trips on salal. Photo: Jay Pscheidt, OSU

Thrips on Salal.  The following is OSU Plant Pathologist Jay Pscheidt’s response to a client regarding damage on Salal: “We have heard about this in the south west part of the state near the coast. The cause is not azalea lace bug (although the damage is surprisingly similar) but the greenhouse thrips, Heliothrips haemorrhoidalis. As the common name suggests, this pest is predominantly associated with greenhouses in temperate climates as it is supposedly not cold hardy. It can be a significant pest in warmer climates, such as California in the avocado areas and in Florida. It predominantly attacks shrubs or trees. We’ve seen it in greenhouses for years but found it in outside samples from Hoyt Arboretum several years ago. Many years ago, it was causing substantial landscape damage in the Seattle area to viburnum and salal among other shrubs.” (Jay Pscheidt Facebook 1-4-21) PNW Disease Management Handbook:

Meet the World’s Least-Charismatic Orchid. “This newly described species has been dubbed “the ugliest.” (Jessica Leigh Hester, Atlas Obscura)

WSU Extension publications has a wealth of peer reviewed gardening information.  Check out a sampling:

Do Black Walnut Trees Have Allelopathic Effects on Other Plants? (Home Garden Series) (Dr. Linda Chalker-Scott, WSU)

Epsom Salt Use in Home Gardens and Landscapes. (Dr. Linda Chalker- Scott, Rich Guggenheim, WSU)

Gypsum Use in Home Gardens and Landscapes. (Dr. Linda-Chalker-Scott, Rich Guggenheim WSU

Home Pruning: Reasons to Prune Trees and Shrubs (Home Gardening Series.) Tim Kohlhauff, WSU; et al.

Hugelkultur: What is it, and should it be used in home gardens?  “Hügelkultur is an increasingly popular way of using organic material to create mounded home gardens and landscapes.” (Dr. Linda Chalker-Scott, WSU)

Convergens lady beetle
Convergens lady beetle. Photo: OSU

Lady Beetles: Should We Buy Them For Our Gardens? (Home Garden Series.)  “Lady beetles are a popular biocontrol method for aphids in home gardens and landscapes. Many gardeners purchase these insects at nurseries, garden centers, and online.” (Dr. Linda Chalker-Scott, Michael R. Bush, WSU)

Vegetables: Growing Peppers in Home Gardens (Home Garden Series.)   “Looking for a way to spice up your home garden? There are few vegetables more colorful or easier to grow than peppers.” (Michael R. Bush, WSU; et al)

Natter’s Notes

Jean R. Natter, OSU Master Gardener

In case you haven’t been outdoors recently, you need to know weeds are growing in spite of the soggy soil from all the recent abundant, rainfall. So, let’s review a few strategic management strategies for successful weed control in gardens and landscapes. As you may know, the PNW Weed Management Handbook (see resource list) has a thorough overview of the subject.

Annual weeds are classified as warm-season or cool-season plants, with each kind genetically destined to germinate (sprout) in the appropriate season, then survive for a year or somewhat less. The same categories are assigned to perennial weeds but these are considerably more long-lived, persisting for 3 or more years.

As a result, gardeners must be vigilant year-round.  

Several key principles limit weed populations in gardens and landscapes, among them these:

– Kill weeds when they’re young; ten fingers are always at hand.

– Don’t allow weeds to set seed.

– Annual weeds will die when cut just below the crown.  Use a knife, or any one of various hoes – standard garden hoe, diamond hoe, or a scuffle hoe.

– Perennials will re-grow when cut off, even if covered with mulch  Vigorous kinds will make it through a lasagna garden; and may lift landscape fabric and/or polyethylene sheeting. 

– To kill perennial weeds, you must starve the roots; to do so, remove all green growth every week for as long as it takes, very likely several years.

– Herbicides are rarely a “once-and-done” remedy.

Gardeners can make good use of creating a “stale seedbed” before planting a flower or vegetable bed, or even a lawn. The reason?  Hundreds of dormant seeds — termed the “Soil seed bank” – have been deposited in the soil during years and years of poorly managed, or unmanaged, weeds. Whenever soil is disturbed, some of those seeds are brought near the surface where they germinate because they are exposed to light, also appropriate temperatures and moisture.  

Start a stale seedbed a month or so prior to the desired planting date, thereby allowing for a cycle or two removing weed seedlings.  Do everything needed to prepare the planting bed: dig; remove obstructions and weeds; amend the bed; level the soil; then moisten the soil to settle it and allow for germination.  As soon as a good stand of young weeds about inch tall is present, destroy them using your preferred method: hand, hoe, flamer or, if you must, herbicide. 

The earlier a stale seedbed is started, the more germination cycles possible, the fewer weeds will be present to steal water and light from the desired crop.  Next, seed or transplant your veggies or flowers with minimal disruption of the soil, and deal with any seedling weeds promptly.

With perennial weeds, choose among these destructive techniques:

1. Dig it out; repeat as needed.

2. Cut it off; repeat as needed.

3. Herbicides are effective if the right kind is used according to label directions; repeat as needed for re-growth and/or use #1 and #2, above.

Tools to help limit weeds:

– Hands

– Hoes

– Herbicides, organic or synthetic: Contact products kill only top growth (fine for annual and seedling weeds); systemic products translocate (move) into other plant parts, sometimes into roots.

– Mulch, with the understanding that new weeds, in the form of seeds, will continue to arrive via clothing; muddy boots; new plants; birds; hitchhikers on mowers; or may be blown in.

– Flamer

Some trees are known to put up root suckers after they are cut down, among them are such broadleaf trees as ash, aspen, cottonwood, flowering cherry and poplar.  Conifers won’t re-sprout, even if the roots remain in the ground.

To limit root sprouting after a broadleaf tree is removed:

– Cut down the tree as soon as the new leaves have fully expanded in spring. 

(Principle: The tree used most of its reserves for new foliage, thus the stump/roots will put up fewer sprouts than if the tree is removed later in the season.)

– Immediately after the tree is cut off, paint a 2-inch-wide band of the other edge of the cut surface with an herbicide such as triclopyr or 2,4-D, following label directions.

– Remove new shoots as soon as they’re seen:

       – The more often new greenery is removed, the better the chances of decreasing the roots’ reserves; once a week is a good plan.

       – The longer new growth remains, the more reserves it sends to the roots, thereby extending the battle. 

– Be persistent and you will win; pause for a season and you lose.


– Sustainable Gardening (your MG Handbook)

– Weeds and Your Garden:;sequence=1

– PNW Weed Management Handbook: Online at  

– PNW Weed image gallery (from the 2010 Weed Handbook): Organized by common name, each weed with 1 to 3 images: seedling, flower and/or mature.

– Weeds and other unwanted plants (text and images)

By Margaret Bayne, OSU Extension Service Staff-retired, OSU Master Gardener

Open hands with palms holding corn gluten meal.
Corn Gluten Meal. Photo: University of Connecticut

Cornmeal magic – the myth that will not die.  Learn the facts! (Dr. Linda Chalker-Scott, WSU)

The complicated issue of heavy metals in residential soils, part 2: How plant species and environmental variables complicate the issue. (Dr. Linda Chalker-Scott,

Soil Myth Busting for Extension Educators: Reviewing the Literature on Soil Nutrition. (Dr. Linda-Chalker Scott, WSY ; A.J. Downer, U of CA via

Reviewing the literature on tree planting- Landscape Trees. (Dr. Linda Chalker-Scott, WSU & A. J. Downer, U of CA; via

Soil Myth Busting for Extension Educators: Reviewing the literature Soil Structure and Functionality. (Dr. Linda Chalker-Scott, WSU & A. J. Downer, U of CA via

Check out some new and exciting new plants! (National Garden Bureau)

The horrors of mass-produced bee houses. (Note: while a commercial, has useful info and links) (Collin

Blueberry plant with ripening berries.
‘Legacy’ blueberry. Photo: Bernadine Strik, OSU

REVISED PUBLICATION: Growing Blueberries in Your Home Garden. (Bernadine Strik, OSU; et al: EC 1304)

Hummingbird Drone Films Half a Billion Monarch Butterflies Taking Flight. (

Just for fun: Bugs and Organisms look like Monsters Under a Microscope.  Ever wondered what an ant or wasp looked like up close?  Have a look! (

Soil fungi act like a support network for trees. New research is first to show that growth rate of adult trees is linked to fungal networks colonizing their roots. (U of Alberta, via

Pollinators of Butterfly Bush (and Other Questions) (stillca, OSU)

20 Questions on Plant Diagnosis– “This is the third fact sheet in a series of 10 designed to provide an overview of key concepts in plant pathology. Plant pathology is the study of plant disease including the reasons why plants get sick and how to control or manage healthy plants.” (Joe Boggs, Ohio State, et al)

Golden foliage of larch trees in forest of evergreen trees form a smiling face in the midst of the dark green foliage of the evergreen trees.
Larch among Douglas Fir. Photo: Jay Pscheidt, OSU

The Deciduous Conifer Conundrum. (

Natter’s Notes

Jean R. Natter, OSU Master Gardener

Early in 2020, a new pest of mason bee, Cacoxenus indagator, was identified in Washington State for the first time. It’s often referred to as the Houdini Fly because of the unique way it escapes from the mason bee’s nesting cell. It’s also nicknamed the Red Devil due to its large red eyes, or just Devil Fly. It’s presence in Oregon is suspected to but not yet verified.

Fig 1 – houdini fly, BugGuide

The arrival of the Houdini fly is suspected to be an unfortunate example of moving bees without carefully inspecting them and their nests prior to the move. “In New York, the first two records were in 2011, although it may have arrived there earlier. It had presumably come there from Europe, probably someone moving an unclean nest block,” said Josh Vlach, from the Oregon Department of Agriculture during an interview by Andony Melathopolous during PolliNation Podcast #154 (2020).

What damage does the fly cause?

“The flies don’t actually attack the bees; they’re kleptoparasites,” continued Vlach.  “The fly is in the same group as Drosophila fruit flies that fly around a bowl of over-ripe fruit.” They closely resemble their fruit fly cousins – about the same size, with large red eyes, but otherwise a dull brown color. They move rather sluggishly, and are often seen near the entry to a nesting tunnel.

After the mother bee leaves the nesting tunnel, the Houdini fly enters the tube, lays eggs on the pollen ball, then quickly exits. After the nesting cell is closed by the mother mason bee, the fly larvae hatch and eat the pollen ball. As a result, the mason bee larva starves.

Fig 2 – Cacoxenus indagator

 How to recognize an infestation

Telltale signs of these kleptoparasitic flies are sticky clusters of small white maggots in a nest cell. The bee larva is dead or missing. [Note: Kleptoparasite may be spelled with a “c” as in cleptoparasite.] But beware! Another pest, a parasitoid, produces a similar cluster of small white larvae.

Be aware of a look-alike infestation by tiny wasps

Unfortunately, to the untrained eye, the white larvae of Monodontomerus wasps could be mistaken for Houdini fly maggots. These small black wasps – sometimes referred to as ‘Mono’ wasps – are much more active than adult Houdini flies. The adult wasps erratically flit about. They’re parasitoids which lay multiple eggs in a single mason bee larva. However, the end point is the same as with the Houdini flies: Dead mason bees.

Management suggestions for Houdini flies (WSDA Pest Alert)

–  Harvest mason bee cocoons – Open mason bee nesting materials before they emerge in the spring and destroy Houdini fly maggots.

– Control adult mason bee emergence – If you cannot open nesting materials, place your nesting materials in a fine mesh bag and close tightly. As the bees emerge, release the mason bees daily and kill any Houdini flies.

– Only use nesting materials that allow you to open, inspect, and harvest cocoons. Visual inspections can greatly reduce Houdini fly populations. (Ed. note: Kill the larvae on sight.]

– Before purchasing mason bees, ask the provider how they harvested and whether they inspected the cocoons for Houdini fly.

Only purchase pest-free mason bee cocoons.

A few final words

– WSDA suggests: “Please do not unnecessarily move bee blocks or boxes around.”

– If you’re having sizeable losses of healthy mason bee cocoons, seriously consider modifying your materials, methods, and procedures.

– A viable alternative to using clustered artificial housing for native bees is a healthy environment with modest-sized patches of suitable flowering plants that provide a year-round succession of bloom

– Perhaps the best habitats for native bees are patches of bare soil, along with naturally-occurring tubes, among them spent plant stems and old holes from boring beetles, all in a pesticide-free location.


– PolliNation transcript #154 – An interview with Josh Vlach, ODA. (

– “Parasitoids and Cleptos”- [Caution: “. . .artificial bee nests and hotels may be preferentially used by introduced bee species and native wasps, rather than native bees]

– Video: Houdini fly, a kleptoparasite of Osmia –

– Video: Life cycle of Montodontomerus wasp – 

– “How to Manage the Blue Orchard Bee”- An overview.

– “Orchard Mason Bee” (10-Minute University) — Orchard Mason Bees (

 – Pest Alert WSDA//  Houdini fly found in Washington; images and 2 videos:

Video: How does Cacoxenus escape?; Video:Devil fly on nesting tubes. “The accompanying fauna of Osmia cornuta and Osmiarufa” – Pests of Osmia in Europe, with images –

Snowdrop flowers emerging out of snow.

Every gardener knows under the cloak of winter lies a miracle – a seed waiting to sprout, a bulb opening to light, a bud straining to unfurl. And the anticipation nurtures our dream.

Barbara Winkler

Learning and growing in the new year…

As we start the new year with much hope and anticipation, we are excited to share the upcoming OSU Extension Service Master Gardener Program offerings for 2021.


Long stairway ascending through natural greenway.

Current OSU Master Gardeners (including the class of 2020) have the opportunity to be inspired with the ‘Elevated Skills’ training, taught by OSU Extension staff. A wide-range of topics aim to enrich and support Master Gardeners. ‘Garden plant ID with the OSU Landscape Plant Database’, ‘Superpower Your Education Garden’, ‘Community Science and the Master Gardener Program’ are just a few of of the many offerings to inspire and elevate Master Gardeners as community educators. Registration details to come.

Level Up

Slow motion video of Dahlia flower blooming.

OSU Master Gardeners and the gardening public can get ready to ‘Level Up’ in a new series for experienced gardeners, with presentations by OSU horticulture experts. Take your gardening knowledge to a new level with timely topics from gardening in a changing climate to techniques to extend your season.

This monthly webinar series kicks off Tuesday, January 12, 3pm, focusing on ‘Understanding Seed Characteristics’. Register in advance and level up!

The Culture of Gardening

Hands harvesting greens.
Photo credit: University of Maine

Come spring, Master Gardeners can participate in ‘The Culture of Gardening’. Explore what gardening means to different people and groups, and how to grow and use plants from a variety of cultures. This new series of blog posts and talks will debut in late spring 2021, with a keynote address by horticulturist Abra Lee on the history of African American gardens and gardeners. The series kicks off on May 18th. Details to come.

Get ready, to get growing!

Invitation to Dr. Martin Luther King Jr. Day Celebration

What does the legacy of Dr. Martin Luther King, Jr. mean to you? As a Master Gardener? As a gardener? How can we honor his teachings in our own work?

Dr. Martin Luther King Jr. with overlaid quote "Be a bush if you can't be a tree. If you can't be a highway, just be a trail. If you can't be a sun, be a star. For it isn't by size that you win or fail. Be the best of whatever you are."

Join us for a moderated online Zoom discussion January 18th, 7pm. See registration link below.

As part of the University-wide 39th Annual Dr. Martin Luther King, Jr. Celebration, OSU Extension Master Gardener volunteers and staff are invited ahead of time to read, view and reflect upon materials and prompts of inclusion and identity as gardeners and Master Gardeners. These include:  

Listen to and reflect upon the YouTube interview of Abra Lee, by Annie Guilfoyle and Noel Kingsbury of Garden Masterclass. View here.

Read and reflect upon the article posted on the Oregon Humanities Website about farming as a form of homecoming for the African American community in Portland. Read here.

Watch the presentation: Steady & Focused:  Efforts to Promote Racial Justice in Oregon’s Master Gardener Program. This talk was given earlier this year at Cornell University’s Ag In-Service Day and at the National Extension Master Gardener Conference by OSU Extension Master Gardener leadership Gail Langelotto and LeAnn Locher. Watch here.

Use Google Image Search to search for the terms, below. What do you notice about the images that are returned with these search terms? What does it say about who is or can be a gardener or Master Gardener?

• Gardener
• Master Gardener

Attend the keynote address for OSU’s 39th Annual Martin Luther King Jr. Celebration, delivered by Dr. Angela Davis, January 18, 9:30am to 10:30am. The event is free and open to the public. Register here.

Register here for the moderated January 18th, 7pm, online Zoom discussion, with fellow OSU Master Gardeners and staff.

Our January and February Garden Checklist

No need to be idle in winter. Our garden checklist guides you through forcing some early blooms, winter pruning, covering sensitive plants and planning your spring vegetable garden.