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

Watch leaves change color in a matter of seconds.  “A new time-lapse video of over 6,000 leaf photos reveals the biology behind fall foliage.  As foliage darkens in the fall, the pigments within the plant matter break down and transform.” (Emily Toomey,

Find out where the fall foliage will be at its peak across the country.(Natalie B. Compton,

How Plants Measure Their CO2 Uptake.  “Plants face a dilemma in dry conditions: they have to seal themselves off to prevent losing too much water but this also limits their uptake of carbon dioxide. A sensory network assures that the plant strikes the right balance.

Watch the four finalist videos in the 2019 YouTube your entomology contest.(

Exposed tree roots.
Exposed tree roots. Michael Hoelzl/ Creative Commons

Great Tree Root articles with links to resources: SelecTree: Right tree right place. (selectree.calpoly)

Tree roots and foundation damage. (The Morton

Trees are not the root of sidewalk problems. (T. Davis Sydnor1, et al; Journal of Arboriculture)

Soil’s Microbial Market Shows the Ruthless Side of Forests.  “In the ‘underground economy’ for soil nutrients, fungi strike hard bargains and punish plants that won’t meet their price.” (Gabriel Popkin,

Daisies that close at night have camouflaged petals to protect them from herbivores. (

Professional credentials and gardening expertise: Entomologists (Colby Moorberg, More info:

Tree and shrub sampling for disease diagnosis.  Watch the video and learn  what makes a good sample for diagnosis.” (NC State U via

A brown rat eating seeds from ground.
Rat, OSU

Tips for keeping rats out of home and garden. (Kym Pokorny, OSU; source: Dana Sanchez, OSU)

Could biological clocks in plants set the time for crop spraying?  “Plants can tell the time, and this affects their responses to certain herbicides used in agriculture according to new research…” (Dr. Antony Dodd, University of Bristol)

See the microscopic wonders of herbs!  “A photographer reveals the intricacies of kitchen herbs. The result is otherworldly.” (Rob Dunn,; photos by Martin Oeggerli)

European honey bee, gathering pollen from flower, with large, light yellow pollen sacks on hind legs.
European Honey bee, University of Florida

Surprise…bees need meat!Ask an entomologist what makes a bee a bee, and you’ll likely get some version of “bees are just wasps that went vegetarian.” New research shows that isn’t true. Bees are actually omnivores, and their meat is microbes.” (Paige Embry,

The journey of pollen.  “Kiel research team deciphers adhesive mechanisms in pollination.” (Kiel University)

Western Red Cedars Dying

Jean R. Natter, OSU Extension Master Gardener

Failing trees have been a persistent topic in MG Clinics and on the online Ask an Expert service during the past 6 or 7 years. Overall, it’s been an issue of continuing higher than normal temperatures combined with less than normal rainfall. Then, too, few homeowners realize that the continuing heat and drought affects their landscape trees in spite of being watered with the lawn sprinklers.

Fig 1 (right): Western red cedar, Thuja plicata, with thinning crowns most likely due to climate changes and continuing drought. (“Why is My Tree Dying? – Western Redcedar (Thuja plicata)” – April 2019;

In order for trees to thrive, they should be irrigated separately from grass, with at least one watering to about 10 inches deep to the soil below the canopy every 3 weeks during our dry season. Indications of a water deficit is revealed by multiple signs and symptoms, among them wilted leaves; leaves with curled and/or dry edges; early fall color; leaf yellowing and early leaf drop.

Foresters have been puzzled by problems with Western Red Cedar (Thuja plicata) which normally do well on moist sites. The most recent thought is that these trees are finally succumbing to stress from many successive years of heat and drought stress.

Several recent Ask an Expert responses have noted “We are getting many reports of western redcedars dying this year, and the consensus seems to be that the combination of extreme heat and drought experienced since around 2013 through last summer is an important factor. Although this summer was mild, it often takes a year or so for a tree to show any signs of distress from drought.”

Another expert, in a response to a different client, said it this way: “Western redcedar are dying in some areas due to a complex of climate stress and other issues, with no clear primary agent of mortality.”

Two Western Red Cedars at the Oregon State University campus

Fig 2 (right): Two healthy Western red cedars (Thuja plicata) on the Oregon State University campus, southeast of Fairbanks Hall. ( OSU Landscape Plants;

In general, the foresters responding through Ask an Expert are including a link to a publication released in April 2019: “Why is My Tree Dying? – Western Redcedar (Thuja plicata)” which, in summary, states:

Top-dieback, branch mortality, crown thinning and whole-tree mortality in all ages of western redcedar has [sic] been observed recently at lower elevations in the Willamette Valley and beyond. Although it is common to see ‘spiked’ or dead tops in older western redcedar, usually there are living lateral branches and a functional crown. No single factor has been identified in these more recent die offs, but a combination of poor or unsustainable growing conditions may be to blame. Redcedar may simply be growing in areas or within microclimates outside of their preferred range or areas that are no longer sustainable for long-term growth under current climate conditions.

Then, too, it suggests that alternate species for red cedar on generally dry sites include incense cedar, sequoia, and big leaf maple; on more moist sites which don’t dry out in the summer, western white pine, maple, alder, ash, or cottonwood.


– Abiotic Disorders of Landscape Plants” (#3420 UCANR); pages 51-59. A copy is in each of the metro MG offices.

“Thuja plicata (Western Red Cedar)” outlines a basic description of this native conifer (50-70 feet, or more) which thrives in sun to part shade on moist soils, with numerous images of a healthy tree.

– “Why is My Tree Dying? – Western Redcedar (Thuja plicata)” – April 2019 –

– “Pruning Drought Stressed Shade Trees” encourages caution to remove as little wood as possible from a stressed tree, in part because it already has limited reserves, with precious little remaining to “spend” on otherwise unneeded wound repair.

old pear tree
starlings announce
harvest time

–  Philip Noble

Our Annual Harvest (of volunteer service hours that is!)

It is that time of year when we are busy harvesting in our gardens, whether herbs, fruit, vegetables, or flowers. For OSU Master Gardener volunteers, it is also time to gather and record your hours of volunteer service and submit your volunteer log sheet, prior to the October 1st deadline.

This year Metro-area Master Gardeners have made tremendous contributions educating and supporting home gardeners, and we want to share the news!

The October 1st deadline allows the metro MG program office enough time to compile and share your significant contributions, with the state Master Gardener program and OSU Extension Service.

Help us get those statistics to the state level by recording and submitting your hours this month!  We will celebrate and share the grand totals at our Fall Recertification Training.  See the article below for reporting details.

Online MG Volunteer Reporting System

We have an updated online volunteer reporting system to ease the process of submitting your volunteer hours and signed 2019-2020 Conditions of Volunteer Service form.

To report using the online system – follow the links sent to you in an email that was sent from Marcia McIntyre on September 5th

The online system prompts you through several questions to record your volunteer hours, provides a special email in which to send your volunteer log sheet, plus the options to send your yearly Conditions of Volunteer Service via mail, email or DocuSign!

You still need to record your volunteer hours onto a Word, Excel or PDF form – but now you can upload those hours via the online system.

NOTE:  You can refer to your CERVIS log to track your hours – but you also need to log all CERVIS hours on your volunteer log sheet.  Most “Program” hours are recorded in CERVIS.  “Partner” events and activities are not recorded in CERVIS (this includes Chapter events, plant sale support, Chapter demonstration/education garden volunteer service).  Be sure to record all your volunteer hours and continuing education hours on your log sheet.

A special thank you to those who have already submitted your hours!  Great going, early birds!

For those of you who are still seeking Recertification/continuing education or volunteer opportunities look for some great opportunities below.

How to Maintain Master Gardener Certification

Need a refresher on how to maintain your Master Gardener certification?  Here you can find the details.  Whether you are a 2019 trainee or a Perennial MG, to continue to serve as a “current” OSU Master Gardener you must submit an annual, signed Conditions of Volunteer Service form, which can be signed via DocuSign (see article above and email received from Marcia McIntyre on September 5th). 

Fun fall Farmers Market volunteer opportunities, sign-up on CERVIS!

3 OSU Master Gardeners at the Rocky Butte Farmers Market, talking to client

Fall is a wonderful time to volunteer at area Farmers Markets, as autumn produce lines the aisles and seasonal home gardening questions abound.

Opportunities to volunteer at a Farmers Market remain for Beaverton, Gresham, Hillsdale, Lake Oswego, Lents, and Tigard.  Grab an open slot on CERVIS

Guide home gardeners through the fall and winter season!

2 Master Gardeners sitting in Master Gardener helpline clinic, look at a large branch with leaves, as a client leans over and points at the branch.

As the days shorten and the temperatures cool, a new host of gardening conundrums perplex the home gardener. You can assist and expand your own knowledge, collaborating with other MGs as you research and advise gardeners.  Sign-up on CERVIS or contact a phone coordinator.

Save the Date!  Saturday, November 9th – FALL RECERTIFICATION! 

Metallic bee (bright green) on orange cone flower

Our annual Master Gardener Fall Recertification Training is scheduled for Saturday, November 9th, 8:00am to 3:45pm, at Clackamas Community College.  This annual event is a daylong continuing education opportunity.  Earn 6 hours of continuing education/recertification credit by attending.

Photo: Oregon State University

Please join us for an engaging day of training that will support you in your role as a garden educator.

‘A Diverse Garden is a Healthy Garden – Diversity, Equity, and Inclusion in your role as an OSU Master Gardener volunteer.’  Presenters: Yolando Sánchez, Jeff Selby, and Koffie Dessou of the City of Portland, Office of Equity and Human Rights

‘How trees grow and why they die!’ Presenter: Glenn Ahrens, OSU Extension Forester, Clackamas, Hood River, and Marion Counties

‘Is the Insect Apocalypse Upon Us?’ Presenter: Gail Langellotto, Statewide Coordinator, OSU Extension Master Gardener Program, Associate Professor of Horticulture, OSU

*Attendance and participation at the November 9th, Fall Recertification Training counts as 6 hours continuing education credit for the 2019-2020 Master Gardener Volunteer Season.  Record your attendance on your 2020 Volunteer Log.

2019 Master Gardener Trainees to Receive OSU MG Badges

2018 Master Gardener gives thumbs up as she proudly wears her OSU Master Gardener badge

Our November 9th, Fall Recertification Training (see details above) also gives us the opportunity to congratulate the new class of Master Gardener interns as they step-up to Perennial Master Gardener status, after completing their volunteer requirements.

2019 Interns are cordially invited to attend the full day of Fall Recertification training, which will count toward your continuing education hour requirement for 2020.  If you are unable to attend Fall Recertification to receive your badge, it will be mail to those not present in December.

Welcome Leah and Catalina!

Leah Sundquist and Catalina Santamaria

We want to introduce you to two new faces at the Clackamas County Extension Office (where our MG program team is located). 

Photo: Leah (left) and Catalina (right).

Leah Sundquist is the new Clackamas Co. Extension Office Manager.  Leah joins the Extension team after a 35-year career in the U.S. Army, where her final years of service included roles as the Chief of Staff and Director of Plans and Operations for the Oregon National Guard in Salem.  When asked about her experience with gardening, Leah shares that she is proud to be nurturing her office ‘welcome gift’ jade plant, the past 3 and a half months, with the plant showing nary a sign of distress.  She is nurturing an olive tree with hopes that, if it survives, she can reward herself by purchasing another one!

Catalina Santamaria joined our Extension team in July, as Office Specialist in the front office.  A portion of Catalina’s time will be supporting the Master Gardener and 4-H program.  We are excited that Catalina is joining our MG team. Catalina will be coordinating the Clackamas County MG office helpline and working alongside the MG team.  Catalina shares that her exposure to gardening started as a young child, as her father grew many plants at home.  She recalls many cyclamen and African violets brightening her childhood home.

Please join us in extending a warm, Master Gardener welcome to both Leah and Catalina! 

September Master Gardener Advanced Training Webinars

Here comes another great Master Gardener Advanced Training Webinar, offered on Tuesday, September 17th, 11am.

cherries on branch of cherry tree

Are Viruses Lurking in Your Backyard Cherries?
Presented by Lauri Lutes (OSU Botany and Plant Pathology PhD student)
Register here:

Join Lauri Lutes, PhD Candidate in OSU’s Department of Botany and Plant Pathology, as she shares what she has learned studying viruses and diseases to which cherries are susceptible in Oregon.  Lauri will share disease prevention and management for cherries in your home garden.  She will also cover how to choose the best tree, common virus symptom identification, and virus vector (insect and nematode) management.

If you are unable to watch the webinar live, check back in a couple of days at the 2019 Advanced Training Webinar page, where a recording of the webinar will be posted.

More Advanced Training Webinars

The OSU Advanced Training Webinars are a great way to stay up-to-date on the latest in horticultural science.   This series features University experts who offer a wealth of research-based information on home gardening topics, which support you in your role as a garden educator.   Check out the great library of webinar recordings.

2019 Advanced Training Webinars

2018 Advanced Training Webinars

2017 Advanced Training Webinars

*MG Advanced Training Webinars count as 1-hour continuing education credit.  You may count any webinar, from any year, that you watch for the first time. List any Advanced Training Webinars that you view on your Volunteer Log Sheet. 

Create Gardens Accessible to All!

raised garden bed with leafy vegetables, a wheel barrel alongside the raised bed. The wheel barrel is filled with plants.

‘Gardening is one of the more therapeutic things a person can do – emotionally, mentally and physically – but for some it seems out of reach. Good design and the practices can make a gardening accessible for everyone.’

Fellow Metro-area, OSU Master Gardener, Corinne Thomas-Kersting, shares some great recommendations for universal garden design in this article ‘Create Gardens Accessible to All’, by OSU Extension Communications Specialist Kym Pokorny.

Gardening Tips for Fall

For your viewing pleasure, we will reprise two great videos with tips for timely gardening activities.

Natter’s Notes

Found in OR: A Native Squash Bee

Jean R. Natter, OSU Master Gardener

female squash bee scopa square jaw, in center of squash flower, legs covered with powdery yellow pollen

This month, let’s talk about a friendly “first record” for Oregon. Instead of a new pest, it’s a native bee previously thought not to be in OR: the squash bee, Peponapis pruinosa, collected for the first time in southern Oregon during 2018.

Fig 1: Female squash bee (above image); numerous pollen grains clinging to the scopa (pollen-collecting hairs) on hind leg of female squash bee; also notice her squared-jaw. (

Thanks for the effective sampling goes to citizen scientists collecting native bees for a survey sponsored by the recently formed Oregon Bee Atlas (OBA). A second sample was acquired later on, again in southern Oregon. 

The Oregon Bee Atlas (OBA) represents the first steps towards gathering and organizing knowledge about our state’s native bees. The OBA’s mission (2018-2021) is to train citizen scientists (committed volunteers) to identify the many native bees known to reside in the state, and to seek new native bee records for the state. After a species checklist has been created, periodic follow-up surveys will be able to determine whether the numbers and health of Oregon bees is improving or declining.

As a result of finding these two bees, the OBA has issued a “squash bee call to action.”

Now that we “have two confirmed samples,” they say, “it would be great to get a map this year of the extent to which these bees have spread through Oregon – even negative results are welcome” In other words, OBA would like its volunteers start looking specifically for squash bees.

This is a project perfect for early risers. Volunteers need to go out early – dawn — before the flowers open, and manually unfurl the flowers.

[Currently, it’s thought likely that squash bees won’t be in the northern part of the Willamette Valley. But who knows? Nature may surprise us.]

The OBA Protocol for locating squash bees:

1. Early in the morning, open mature flowers of the larger flowered Cucurbita species and count the squash bees inside. These are male bees.

2. Only survey zucchini, pumpkin, and other large flowered squashes. Not cucumbers or small flowered plants. 

3. Take photos (clear, focused) of the flowers with squash bees.

4. Record how many squash bees you find in the flowers, collect the bees, then preserve them in rigid containers in your freezer until you contact me ( I‘ll forward your documentation to the OBA.

5. OBA also requests you record the date and time of the collection; your name; the address; latitude; longitude; the flower (pumpkin; squash, etc.); and the number of squash bees in each.

Female honey bee, Apis mellifera, common in landscapes and gardens country-wide.

Differentiating between squash bees and the more common honey bees will be easy. The two bees are about the same size, but the abdomens of squash bees (Fig. 1) are marked with well-defined white bands whereas honey bee abdomens aren’t. (Fig.2)

Fig 2: Female honey bee (above image), Apis mellifera, common in landscapes and gardens country-wide. (


Video: “Journey of the Squash Bees” (UC Davis)

Video: “Squash Bee Natural History” (UC Davis)

“The Bees in Your Backyard” (Wilson & Carril; Princeton University Press; 2016; pages 224-225.)

Images of squash bees, Peponapis pruinosa. (

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

Femail samurai wasp lays egg in mass of Brown Marmorated Stick Bug - Photo credit: Chris Hedstrom - Oregon Department of Agriculture

Researchers determine ideal areas and timing for biological control of invasive stink bug.  (Chris Branam, OSU; source:David Lowenstein, OSU)

Image: Female samurai wasp lays egg in mass of BMSB- Chris Hedstrom-ODA.jpg

Linden (Tilia cordata) associated bumble bee mortality: Metabolomic analysis of nectar and bee muscle study. (Clair Lande, et al;

Tobacco plant ‘stickiness’ aids helpful insects, plant health. While not a crop we have here in Oregon, it is an interesting read. (Mick Kulikowski, NC State U)

Carbon dioxide and oxygen exchange at the soil-atmosphere boundary as affected by various mulch materials. “Mulching is a common soil management technique used in agricultural, nursery, and landscape settings. Despite multiple benefits, such as reducing weeds and evaporation, some mulches can also hinder gas exchange across the soil-atmosphere interface, and thus may have negative impacts on plant growth.(KhurramShahzad, et al;

How spiders increase plant diversity. If healthy ecosystems are what we desire, we must embrace predators. There is no way around it. Because of their meat-based diets, predators can have serious effects on plant diversity. Generally speaking, as plant diversity increases, so does the biodiversity of that region.” (

The world faces ‘pollinator collapse’? How and why the media get the science wrong time and again.”  Interesting piece on a controversial subject. (Jon Entine,

Using flowers, leaves, twigs, and seeds, Canadian artist Raku Inoue creates intricate portraits of insects. Beautiful photos. (Daniel Stone,

Killer wasps invade central Oregon.  “…these wasps infest wherever cicadas have settled, because the females need them for their larvae.” (

Surprising genetic diversity in old growth trees.  “Many trees are often superbly capable of adapting to local conditions. Recently, a team of researchers from the University of British Columbia have provided some insights into the genetic mechanisms that may underpin such adaptive potential.” (

Do ladybugs help your garden grow? Depends on the surroundings. (Krishna Ramanujan, Cornell U)

The surprising history and science of Poison Ivy and its relatives.  “Do you think of poison ivy as a scurrilous weed to be avoided at all costs? Think again! There was a time when the daring and curious found promise in poison ivy and its rash-inducing relatives.”   (Jane E. Boyd & Joseph Rucker,

Dead cedar tree

Western Oregon conifers continue to show damage due to drought. (Kym Pokorny, OSU; Source: Dave Shaw, OSU)

Image: Dead Cedar tree, Dave Shaw, OSU

Can a dead tree help a neighboring tree?Trees are commonly regarded as distinct entities, but the roots of many species fuse to form natural root grafts allowing the exchange of water, carbon, mineral nutrients, and microorganisms between individuals.” (M.K.-F. Bader & S. Leuzinger, Iscience)

Managing plant pests with soaps. “A topic frequently discussed by home gardeners and professionals is the use of soap products to control plant pests. Limited and conflicting information on this topic has resulted in confusion and misuse of products. This document describes some of the different types of soaps and recommendations for proper, legal, and safe use of these products to manage pests.” (Matthew A. Borden and Adam G. Dale, UFL)

Ants that defend plants receive sugar and protein. (Peter Moon, agencia)

Viral disease progress of blueberry shock video. Watch it! (Jay Pscheidt, OSU)

NASA has announced the first fruit they’ll grow on the ISS, And it’s hot. “Researchers are hoping to send up Española chili pepper plants (Capsicum annuum), which could make peppers the very first fruit to be grown in space by US astronauts.” (Jacinta Bowler,

‘Moon trees’ might just be one of the most epic Apollo legacies we’ve heard of.  “On 31 January 1971, the Apollo 14 mission launched from Earth and spent nine days in space. Along with the necessary space gear, scientific equipment, and two golf balls, the Kitty Hawk command module was also housing 500 seeds. You might be surprised to know that those seeds live on today, despite enduring space radiation, and a decontamination mishap.” (Jacinta Bowler,

The windscreen phenomenon: anecdata is not scientific evidence. “The windscreen phenomenon refers to people’s perception that there are fewer insects being splattered on their windscreen than they used to see. It is one of the most common anecdotes presented as evidence of global insect decline in the Insectageddon stories. But anecdotes are not scientific evidence. Anecdotes describe local conditions, not globally-relevant facts.” (Manu Saunders,

Bright, blue hydrangea bloom. Photo credit: Chris Branam, OSU

Guide to pruning Hydrangeas-differences you need to know. (Raymond Bosmans, Professor Emeritus, UMD)

Image: Blue Hydrangea, Chris Branam, OSU

How Dracula orchids lure flies for pollination.With over 28,000 species of orchid, it seems like there’s an orchid for every niche. The Dracula orchid’s niche is mimicking a mushroom.” (Alun Salt,

Cockroaches are rapidly evolving to become “almost impossible” to kill.  “The rise of the superbug cockroach is upon us. A new study has found that German cockroaches (Blattella germanica) are rapidly evolving to become resistant to many widely used bug sprays and insecticides, as well as chemicals they’ve never been directly exposed to, making them near-impossible to eliminate and one step closer to taking over the world.” (Tom Hale,

Long term problems with Tree Gators?  Read what an expert has to say.(Dr. Linda Chalker-Scott, WSU)

A legendary Ozark chestnut tree, thought extinct, is rediscovered.   “The chinquapin was supposed to have been wiped out by blight. Now one determined Missouri naturalist is hand-pollinating trees in secret groves to bring it back.” (Robert Langellier,

Insect repellent fact sheets.  The term “insect repellent” doesn’t accurately reflect how these materials work. They don’t actually repel insects, but rather block the receptors that mosquitoes, gnats, punkies, no-see-ums and other insects use to detect appropriate hosts for them to bite.” (UNH Extension)

Using coffee ground in gardens and landscapes. (Dr. Linda Chalker-Scott, WSU)

10+ bad*ss trees that refused to die even at the harshest conditions. Amazing photos. (

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

July/August 2019

European earwig. Robin Rosetta, OSU

WSU scientists unmask the humble earwig as an apple-protecting predator. (Seth Truscott,, WSU)

Native forest plants rebound when invasive shrubs are removed.  While this relates to the east coast, it is very informative. (Jeff Mulhollem, Penn State U)

Watering space plants is hard, but NASA has a plan. (Ellen Airhart,

Decoding the mathematical secrets of plants’ stunning leaf patterns.  “A Japanese shrub’s unique foliage arrangement leads botanists to rethink plant growth models.” (Maddie Burakoff,

Twice as many plants have gone extinct than birds, mammals, and amphibians combined (Erik Stokstad,

Find out what causes the little white spheres on spinach leaves? (Becky Sideman, U of New Hampshire)

Learn what can be a cause of misshapen strawberries. (

How to tell the difference between bees, wasps, & flies…watch the video! (Dr. Gail Langellotto-Rhodaback, OSU via youtube)

Hydrangea. OSU

How are hydrangea flower colors determined? (Dr. Linda Chalker-Scott, FS309E, WSU)

Photosynthesis at work…cool video! (BBC via youtube)

Why calcium deficiency is not the cause of blossom-end rot in tomato and pepper fruit – a reappraisal. (Max C. Saure,

Flowers can hear buzzing bees—and it makes their nectar sweeter. (Michelle Z. Donahu,

‘X’ marks the spot: The possible benefits of nectar guides to bees and plants. (Anne S. Leonard  & Daniel R. Papaj, British Ecological Society)

Learn about natural insecticides. (Todd Murray: & Catherine Daniels; WSU, OSU, U of ID, PNW publication 649)

White tailed deer. US Forest Service

Learn from an expert about managing wildlife conflicts in your home and garden. (Dana Sanchez, OSU, PNW 719)

Paper wasps capable of behavior that resembles logical reasoning.  “A new study provides the first evidence of transitive inference, the ability to use known relationships to infer unknown relationships, in a nonvertebrate animal: the lowly paper wasp.” (U of Michigan, via


Natter’s Notes

Summer’s Challenges

Jean R. Natter, OSU Master Gardener

Ah, summer.  Thoughts of gentle breezes and abundant harvests. But, wait! Even as I write this, temperatures are soaring. Just how severely plants were damaged by the time you read this will depend upon how rapidly gardeners reacted. Or, better yet, were ahead of the game.

Just how plants are affected by high temperatures depends upon numerous factors, among them the extent and duration of the heat; the relative humidity; windy or not; soil moisture content; also, the kind of plant, its age, site, and general status when the heat hit. Sometimes leaves are only damaged superficially.  Other times, tissues die.

Tissue survival is most likely when the plant is fully hydrated well before the heat hits. After extreme heat arrives, stomates close, inhibiting water uptake by roots. So, whenever a heat wave is predicted, water the night before or early morning, between 2 and 6 AM.

Although sufficient and timely irrigation is important, so is temporary shade. Container-grown plants are especially vulnerable to damage during bright, hot weather. If possible, move them to a shaded site until the heat passes; if that’s impossible, rig temporary shade at least 18 inches overhead.

Avoid wilt

It’s critical to avoid wilting because wilted plants are permanently damaged even if the plant “totally recovers” after it is watered. Vegetables won’t produce the abundant yields gardeners expect.

Wilting is obvious with herbaceous plants, less so with woodies. In all cases, watch for subtle changes in leaf color. Early on, water shortages are signaled by an off-color, a somewhat blue- or gray-green.

Abiotic sunburn rhododendron 2015-07-client.jpg
These rhododendron leaves reveal varying degrees of tissue damage from excessively bright light combined with high temperatures and reflected light. In the yellow zone: the chlorophyll was killed whereas in the brown areas, tissues took the brunt of the damage and are dead. (Client image; 2015-07)

Other effects of excessive heat include the following:

– Leaves droop, a plant’s temporary response to protect tissues from excess sunlight.

– Flower buds shrivel and dry instead of opening.

– Flowers scorch, especially at the petal edges.

– Fruits with insufficient leafy cover, may sunburn, and eventually spoil.

– Pollination fails, such as when immature summer squash doesn’t enlarge and, instead, rots at the blossom end. Or, when tomatoes stop setting fruit, resulting a harvest lull later on.

– Pollination is incomplete, as when summer squash resembles a billy club.

Blossom End Rot in tomatoes

Blossom end rot in tomatoes won’t be recognized by gardeners for a week or two. It’s caused by insufficient transport of calcium to the bottom of the fruit. (No; crushed eggshells in the soil won’t help.)

Early on, you’ll see a slight graying of the skin color on the blossom end. With continued stress, cells die, producing a black area which gradually enlarges and may permeate the entire fruit with a secondary infection (rot). Perhaps most frustrating is, even though damage isn’t visible on the exterior, the internal flesh has rotted. See “Blossom-End Rot of Tomatoes” (FS139;

Abiotic vine maple heat one-sided 2017-08 client.jpg
A thorough history and appropriate images are critical to resolving a diagnosis. If only a few leaves were submitted from this tree with one-sided damage from excessive heat, one would probably assume the tree was dead. (Client image; 2017-08)

General guidelines for water

– Water early in the day so that your plants will meet the rising temperatures well supplied with a fully moist rootball.

– On scorching days, consider adding a second brief supplemental irrigation, perhaps up to half the usual amount, in the early afternoon to “top off” soil moisture.

–  Realize that the output of drip irrigation and soaker lines is in gallons per hour whereas sprinklers, in-ground or not, is gallons per minute.


– “Abiotic Disorders of Landscape Plants” (UC); pages 139 to 155.

– “Diseases of Trees and Shrubs” (Sinclair & Lyon, 2nd edition); pages 492 to 494.

– “How High Heat Affects Vegetables and Other Crop Plants”




PDF Version Summer’s Challenges

“In summer, the song sings itself.” –William Carlos Williams


Summer Volunteer Opportunities Abound!

As summer temperatures rise – so do volunteer opportunities for metro-area Master Gardeners to share proven, successful garden practices with home gardeners.  Upcoming Master Gardener Clinic table volunteer events include the: Cracked Pots Art Show @ Edgefield, Backyard Certification Open Garden Event, Mt. Scott Fuel’s Centennial Celebration, the Clackamas County, Washington County and Oregon State Fairs!

Other rewarding, interactive, garden education volunteer opportunities are available at the Oregon Zoo’s Education Center and Metro’s Blue Lake Discovery Garden.

You can find details for all these educational events on CERVIS.







MG Office Helplines

Two women, and one man give a thumbs up in the Master Gardener office
Mary, Vaughn, and Leah give a thumbs up to volunteering at the MG office helplines.

“I can’t believe all that I’m learning volunteering here!” “It’s great to use the information I learned in class.” “Volunteering at the helpline is my favorite volunteer gig.” “I’m astonished, how much fun this is!”

These are comments shared by both Perennial and Intern Master Gardeners volunteering at the MG office helplines this past month.  Join in the fun!  Schedule a shift this summer!  Research and collaborate with fellow MGs while educating the gardening public.   Sign-up on CERVIS or contact an office coordinator.

Clackamas County, Janet Hohman,
Multnomah County, Janet Hohman,
Washington County, Jenifer Halter,




Summer Farmer’s Markets

Two Master Gardeners standing under a canopy with a banner reading 'Get the Real Dirt Ask a Master Gardener', talking to a man, woman, and child.
Lents Farmers Market

Farmer’s Markets are bustling and Master Gardeners are present at ten area markets to dispense gardening advice.

Schedule a shift via CERVIS for a great summer volunteer experience.  Don’t despair if your favorite market schedule appears full.  Check back often, as schedules change and openings arise throughout the summer – sign-up on the waiting list for a particular shift.  Let a clinic coordinator know if you are willing to serve as a substitute for last minute cancellations at your favorite market.



Beaverton – Gresham – Hillsdale – King – Lake Oswego – Lents – Milwaukie
Oregon City – Sherwood – Tigard


State and County Fair FUN!

2 woman serving at a Master Gardener booth, talking to a man, and showing the man a page in a book. Pointing at a photo in the book.
Clackamas County Fair

If you want a big dose of summer fun, sign-up for an MG Clinic table at one of the county fairs or the Oregon State Fair.  Give sage (OSU proven), garden advice to fair visitors and take a bit of time, before and after your shift, to grab some shaved ice and check out the fair competitions whether it is honey products, the biggest homegrown fruits and veggies, or the best home brew or chocolate layer cake!  Sign-up on CERVIS to grab a shift now!  Fair admission passes provided to all fair volunteers.

Clackamas County Fair, August 13 – 17 (Tuesday – Saturday). Master Gardeners are in a prime location at the Clackamas County Fair with our clinic table right by the entertainment stage, lovely display garden and plant sale. Join-in!   Sign-up on CERVIS or contact coordinator Jane Collier:, 503-266-1191.

10-Minute University at the Clackamas County Fair!
Informative 10-Minute University presentations will take place daily at the Clackamas County Fair at 11:00am in the Floral Department, near our Master Gardener booth.  Come on down, sit a spell, and be inspired!

11:00 am – Wednesday, August 13: Designing a Fall Container.

11:00 am – Thursday, August 14: Seed Saving.

11:00 am – Friday, August 15: Bugs, the Good the Bad, and the Annoying.

Washington County Fair, July 26 – 27 (Friday and Saturday). Master Gardeners will host a Master Gardener Clinic table under the OSU Extension tent at the Washington Co. Fair.  Answer home gardening questions and learn about all the other great OSU Extension Service programs that take place in Washington County.  Sign up on CERVIS

Fun for families too!  In addition to the MG Clinic table, Master Gardeners will be hosting two tables filled with educational resources and activities for families and children, with a focus on pollinators and pollinator-friendly plants.  To volunteer for the family activity tables contact Annie Raich at

Oregon State Fair, August 30 – 31. For the ultimate fair experience, take a quick jaunt to Salem for the Oregon State Fair.  Master Gardeners from around the state host the OSU Extension Master Gardener Clinic.  Our Metro MG program hosts the MG table on Friday, August 30th and Saturday, August 31st.  Don’t miss this festive state celebration! Sign-up on CERVIS

New Hands-on Workshops!

Pruning workshop. Photo courtesy of Angela DeHaven

We have added two new Hands-on Workshops.  First up, a Pruning Practicum at the Learning Gardens Laboratory, followed by a Plant Identification workshop at the Hopkins Demonstration Forest.  For details and to register go to CERVIS.

  • Thursday, July 18th, Pruning Practicum at the Learning Gardens Laboratory, with pruning expert Monica Maggio
  • Saturday, August 17th, Plant Identification, with OSU Forestry Graduate student, Jen Gorski











Community Open House!
OSU’s North Willamette Research and Extension Center

When: Wednesday, July 31, 4:00pm to 7:00pm
NWREC, 15210 NE Miley Rd, Aurora

Woman and man tasting blueberries.
Blueberry tasting at NWREC Open House

Enjoy a beautiful summer evening at the OSU North Willamette Research and Extension Center’s (NWREC) annual Community Open House, Wednesday, July 31, 4:00 pm to 7:00 pm.   NWREC is OSU’s field research center that serves agriculture in the Willamette Valley.  Research at NWREC focuses on berries, tree fruits, Christmas trees, vegetables, specialty seed crops, and small-scale farming.

The Open House will feature Extension faculty and staff sharing informational displays, demonstrations, and explaining their work.  Be sure to stop by the berry-tasting booth to sample recently developed berry varieties.  There will be fun for all ages, including a hay wagon tour, and the ever-popular tractor driving.  Of course, Master Gardeners will be hosting a clinic table answering home gardening questions, along with a garden related activity for visiting children.  OSU Family Food Educators will share resources and expertise for proper food preservation, along with a wide array of tasty preserved food to sample.

Grab a bite to eat at a fundraising barbecue, hosted by Canby, Future Farmers of America parents and students.  They will be serving up delicious grilled fare, plus fresh berry pie!  Farm fresh vegetables will also be for sale.

Join in this fun community event and learn about the valuable agricultural research done at the NWREC.




Log Your Volunteer Hours

Thank you for your passion, energy and volunteer service educating the gardening public.  We want to be sure to have a record of all your efforts.  Here is the link you need, to download the form, to log your volunteer hours.  Even hours recorded on CERVIS need to also be recorded on your individual Volunteer Log Sheet.  Log sheets are due by October 1, 2019.

MG Nuts and Bolts

Need a refresher on how to maintain your OSU Extension Master Gardener certification?  All the nuts and bolts can be found here!

Hands-on Workshops!

Woman talking to students in field.
Hands-on Workshop with Jen Aron

Our hands-on Workshops have had Master Gardeners digging-in with their hands in the soil, practicing pruning cuts, sowing seeds, propagating plants and soaking up a wealth of practical and successful gardening techniques.  This all thanks to our dedicated team of Hands-on Workshop instructors.

Thank you to our fantastic group of Hands-on Workshop instructors who generously shared their knowledge!

  • Jen Aron
  • Margaret Bayne
  • Jane Collier
  • Claudia Groth, with the generous assistance of Rich Becker, Marilyn Frankel, and Linda Goldser
  • Sandy Japely
  • Monica Maggio
  • Luke Maurer
  • Multnomah Co. Chapter Propagation Team – Sally Campbell, Gloria Bennett, Judy Battles, Linda Goldser, Marilyn Frankel, and Heidi Nichols
  • Washington Co. Chapter Propagation Team – Helen Dorbolo, Marian Ewell, Jan Guziec, Jim Kronenberg, Jacki Lindquist, Sally McCulloch, Jacque Myers, Ardis Schroeder, and Marilynn Turner

Best wishes and thanks, Elizabeth Price!

Woman kneeling next to rootball of plant. Others looking on.
Elizabeth Price

The metro-area Master Gardeners are losing a dedicated garden educator as Elizabeth Price packs-up and moves to Central Oregon.  Elizabeth has served the metro-area Master Gardener Study Group (formerly the Interest Group), as a team leader, coordinator, and curator for over 7 years.

Elizabeth created a learning environment that encouraged and fostered continuing education among Master Gardeners who attended the MG Study Group.  She generously shared her extensive knowledge with fellow Master Gardeners, leading Study Group sessions and special Study Group field trips.  Elizabeth would research topics extensively.  She would capture detailed images of subjects and curate highlights from the Study Group ‘Show and Tell’ sessions to share with Study Group participants and metro-area Master Gardeners.

We are grateful to Elizabeth for her selfless generosity educating and championing Master Gardeners as garden educators.  We send our best wishes to Elizabeth and her husband as they make their move to Central Oregon.  We have no doubt, with this move, that a certain Central Oregon Master Gardener program will be gaining a treasured volunteer!  Thank you Elizabeth!




Save the Date!  Saturday, November 9th – Fall Recertification!

Our annual Master Gardener Fall Recertification Training is scheduled for Saturday, November 9th, 8:00am to 3:30pm, at Clackamas Community College.  This annual event is a daylong continuing education opportunity.  Earn 6 hours of continuing education/recertification credit by attending.  Guest presenters will be announced in our September metro-area Master Gardener newsletter.

2019 Master Gardener Trainees to Receive OSU MG Badges

Woman smiling and showing her OSU Master Gardener badge.
Amanda proudly displaying her OSU Master Gardener badge.

Our November 9th, Fall Recertification event also gives us the opportunity to congratulate the new class of Master Gardener Interns as they step-up to Perennial status after completing their volunteer requirements.

We will present 2019 Interns with their OSU Extension Service Master Gardener badges and a big shout-out for successfully completing the program.  2019 Interns are cordially invited to attend the full day of training – which will count toward your continuing education/recertification hours for 2020.


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

June 2019

Is the Insect Apocalypse Upon Us?  Learn the facts from an Entomologist from OSU. (Gail Langellotto-Rhodaback, OSU)

Scientific literacy for the citizen scientist- Learn what “research-based’ means.  Great info for MGs! (Dr. Linda Chalker-Scott & Catherine H. Daniels, WSU)

Black walnut – Oregon State University

Do Black Walnut trees have alleopathic effects on other plants? (Dr. Linda Chalker-Scott, WSU)

Trees with “crown shyness” mysteriously avoid touching each other. (Kelly Richman-Abdou,

Urban trees grow fast and die young.A US study raises questions over the long-term benefits of current city greening schemes.” (Mark Bruer,

Do additives help the soil? Scientist suggests nature knows what’s best. (University of British Columbia Okanagan campus via sciencedaily)

How do I relocate insects and spiders? (joeballenger2005,

How the bumble bee got its stripes (bands.) A new study … has identified the gene responsible for the color switch between the red and black color forms of the bumble bee, Bombus melanopygus.” (Pennsylvania State University via

13 must see trees around the world.  Watch a slideshow of these magnificent trees.(Sidney Stevens,

The hunger gaps: how flowering times affect farmland bees. “Planting wildflower strips is a common strategy for providing pollinators with more food on farmland. These can provide plenty of pollen and nectar for bees to feed on, but most of this food supply is limited to the late spring and early summer when there is already plenty to eat.” (University of Bristol)

Earthworms – Oregon State University

The real reason you see earthworms after rain. (Matthew L. Miller,

Drone reveals ‘extinct’ Hawaiian flower growing on remote cliff. (Russell McLendon,

An endangered Iris with an intriguing pollination syndrome. (

Why plant blindness matters.  “A phenomenon called “plant blindness” means we tend to underappreciate the flora around us. That can have disastrous consequences not only for the environment, but human health.” (Christine Ro,

With flower preferences, bees have a big gap between the sexes.  Female and male bees of the same species frequent different flowers… study finds.” (Rutgers U via

Jill O’Donnell – Michigan State University

Are homemade pesticides even legal?  (Note: OSU Master Gardeners don’t recommend the use of homemade pesticides) (Erin Lizotte, Michigan State U)

Gooey seeds.  “Some seeds can get pretty sticky when water gets involved. Anyone that has ever tried to grow a Chia pet or put chia seeds into water will know what I mean. The seeds of chia (Salvia hispanica) are but one example of seeds that turn gooey with water. The question is, why do they do this? What role does sticky mucilage play in the reproductive cycle of plants around the globe?”

Salk scientists plan to combat climate change with plants.   “A team of plant scientists at The Salk Institute believes their simple idea of harnessing the power of plants to capture carbon dioxide from the atmosphere and store it in their roots could have a dramatic impact on efforts to combat climate change.” (Mark Sauer & Megan Burke,

The scoop on poop: Manure in the vegetable garden (and potential food safety risks) (John Porter,

New interactive website displays massive butterfly and moth collection.  “A new website launched by the University of Alaska Fairbanks will allow the public to view high-resolution images of thousands of butterflies and moths gathered by renowned collector Kenelm Philip.” (Jeff Richardson, University of Alaska Fairbanks)

A woman spent 14 years photographing the planets oldest tree.  Check out these stunning photographs. (Julija Neje,