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

Are we going to see another “Heat Dome” this year? 
Hope not!…but be prepared!  Check out the resources below.

Brown leaves on a plant due to injury caused by a heatwave.
2021 Heatwave Damage – Kym Pokorny, Oregon State University

***Great Publication/book to add to your library: Abiotic Disorders of Landscape Plants; A Diagnostic Guide, Publication #3420, (University of California ANR) ISBN 1-879906-58-9.  Learn the difference between sunburn injury, sunscald injury, thermal/high temperature injury and high light injury.

Brown crinkled leaves of a blackberry plant and discolored, withered blackberries, all damage due to heatwave.
2021 Heatwave damage on blackberries
Bernadine Strik, Oregon State University

What Can We Learn from the ‘Pacific Northwest Heat Dome’ of 2021? (Nicole Bell, WSU)

June 2021 heat impacts on trees explained. (Glen Ahrens, OSU)

What is a ‘heat dome’. (NOAA)

How to care for heat-damaged plants. (Heather Stoven, OSU via Kym Pokorny, OSU)

Tips for gardening in extreme heat. (Erica Chernoh, OSU via Kym Pokorny, OSU)

Heat wave in the garden: how to identify and prevent heat stress in plants. (Nicole Sanchez, OSU)

Environmental injury: Sunscald and Sunburn on Trees

Rhododendron -Sunburn. PNW Disease Handbook

Rhododendron -Leaf Scorch. PNW Disease Handbook

Brown leaf scorch on leaves of Rhododendron plant.
Leaf scorch on Rhododendron
Jay Pscheidt, Oregon State University

The Myth of Hot-Weather Watering “Watering plants on a hot sunny day will scorch their leaves”, (Dr. Linda Chalker-Scott, WSU)

And/or search online:

1. Add “site:edu” to the search word or phrase, but omit the quotes.

2. If you search for sunburn, try “sunburn +plants site:edu” (omit the quote marks).  (Doing so will help limit the number of references to sunburned people!)

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

Mycorrhizae! Myco-what?? (Jim Downer,

Measuring the weather in your garden. (Linda Chalker-Scott,

Japanese Beetle information:

Illustration of Japanese Beetle with a red circle and a slash over the illustration.
Image: Oregon Department of Agriculture

Japanese Beetle Eradication project (Oregon Department of Agriculture)- Maps, look-a- likes, response plan, pesticide info, etc.

Japanese Beetle PDX website:

Effective Management Remains Elusive for Beetle That Eats Almost Anything. (David Coyle,

Popup yard sprinklers spraying water on grass with ornamental flowers in the back ground.
Photo: Lynn Ketchum, Oregon State University

Publications and videos of ‘Gardening Lawn, and Landscape’ resources from OSU.

Peer Reviewed, free download publications from WSU:

Manage Water by Adjusting Lawn Sprinkler Run Time: Instructions for the Columbia Basin of Washington State. (Andrew McGuire, WSU)

Growing Rhubarb in Home Gardens. (Linda Chalker-Scott, WSU

Environmental Injury: Sunscald and Sunburn on Trees. (Marianne Ophardt & Rita Hummel, WSU)

Winter Burn on Evergreens. (Marianne Ophardt & Rita Hummel, WSU)

Protecting Water Resources: Planting and Caring for Home Wetlands and Other Riparian Areas. (Linda Chalker-Scott, WSU)

The Efficacy and Environmental Consequences of Kelp-Based Garden Products. (Linda Chalker-Scott, WSU)

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

Western bumble bee on yellow flower
Western Bumblebee Photo: Stephen Ausmus, Agriculture Research Service, USDA

The ABCs of plants for Bees! (Abi Saeed,

Surfing the “green wave.”  Is it spring yet where you are? How can you tell? (Pam Knox,

An Introduction to growing under lights. (By Miri Talabac, UMD)

VIDEOS from NPIC (National Pesticide Information Center, OSU)

Bacillus thuringiensis:


What does it mean when food is organic?:

Dorsal view of Giant Asian Hornet
Giant Asian Hornet, Oregon Department of Agriculture

How to make irresistible traps for Asian giant hornets using sex.  “Traps placed near nests in China attracted thousands of males.” (Erin Garcia de Jesús,

Insects on a Plane: How Eusocial Ants, Bees, and Wasps Deal With Viruses. (Melissa Mayer,

Mosquito on skin.
Mosquito, National Pesticide Information Center, OSU

Mosquitoes may be attracted to certain colours. (Cassandra Edmunds,

Hidden Diversity: When One Wasp Species is Actually 16. (Entomology today)

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

A Note from Margaret:  Please considering joining us for our twice-monthly Zoom meetings; the first and third Mondays, from 1-3 pm!

Tri-county Master Gardener STUDY GROUP

  • The MG Study Group is a self-organizing collection of seasoned and new MGs (and everything in between) who love to learn!
  • We serve all three counties via our Zoom meetings: Clackamas, Multnomah & Washington.
  • We meet twice a month to develop our skills in identifying and understanding insects, spiders, and plant diseases and disorders, etc.
  • Meetings are based on group participation.
  • All interested OSU MGs and interns are welcome. (We are not open to the general public)
  • Attendance is not required; join us when we can!
  • On first Mondays we generally conduct an informal show-and-tell session, where MGs share samples of insects, spiders, plants for identification and/or diagnosis by the group. This is a great deal of fun and no advance work is required except for collecting a sample. (If you don’t have a sample-no problem! Join us anyway).
  • The third Monday is a more formal session based on a Study Guide you receive about a week ahead.  Study Guides are developed voluntarily by attendees about subjects that are of interest to them and to share with the group.  Upcoming Study Guide session topics for 2022Bullies in the Garden-Invasive and Overly Enthusiastic Plants, Summer Heat Woes, Downy Mildew, Pruning, Blackberries, Best Garden Practices, and a Group Diagnostic practice.
Moss in lawn. Brain McDonald, OSU

VIDEO:  Managing Moss in Lawns. (Alex Kowalewski, OSU via youtube)

PUBLICATION: Managing Moss in Lawns in Western Oregon. (Brooke Edmunds, Alec Kowalewski, OSU) (View or download a pdf.)

Practical Lawn Care for Western Oregon. (Doug Vonderberg, Alec Kowalewski, OSU)

Great information about dogs and lawns: Dog Spots! No, not dalmatians but dead spots in the lawn. With the low rainfall and lack of irrigation pet owners may be seeing dog injury to their lawns. Urine damage can be mistaken for symptoms of several patch-type diseases. Samples of the dead grass placed in a plastic bag will release ammonia, which can be detected by smell. Other chemical injury such as fertilizer spills or salt spills can cause similar symptoms but do not release an ammonia odor. Female dogs are usually more damaging as they urinate on the ground, in the same spot and tend to empty their bladders more completely than males. And FYI, yes, this is research-based info!” (PNW Plant Disease Management on Facebook) More information:

Spruce cones could scrub carbon emissions as effectively as costly chemicals.  A new material to capture carbon dioxide comes from a surprising green source: spruce cones.” (Prachi Patel,

The world’s most unwanted plants help trees make more fruit. (Angela Nicoletti, Florida International University

Big leaf maple trees. Patrick Breen, OSU

Video & article: First-of-its-kind estimate of the total number of tree species. (Purdue University)

The Gardens of Chernobyl 30 years after the disaster. (Jim Downer,

Unearthly Plant Photos by Tom Leighton Highlight Nighttime Chemical Processes. (Anna Marks,

Western Monarch Butterfly. Lynn Ketchum. OSU

Western monarch populations grew over 100-fold in 2021. Why?  The beloved butterflies had fallen to critical levels in recent years. Experts weigh in on what might be causing their remarkable return.” (Alissa

More on this topic: How Little We Know About Monarchs… (Kathy Keatley Garvey, University of California)

Discovery of ancient plant fossils in Washington points to paleobotanic mystery. (University of Kansas)

Just for fun!  Idaho Potato Commission Releases French Fry Scented Perfume. (

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

Critters digging up your lawn and garden?  Here are some resources on voles, moles and gophers:

Pruning saw (upper left), a long‑handled pruning shears (center), and hand shears (bottom).
Pruning tools – OSU

Moles, voles and gophers dig the garden. (Dana Sanchez, OSU)

Meadow Voles and Pocket Gophers: Management in Lawns, Gardens, and Croplands. (Gunn et al,

People and Plants-“…a look at the German botanist Adam Lonicer.” (Sylvia Thompson-Hacker,

VIDEO: Pruning Fruit Trees. (OSU Clackamas County MG, Clackamas County TV via Youtube)

In a New Study, Spring Forest Bees Get Their Due. (Leslie Mertz, Ph.D,

Back-Seat Driver: The Parasite That Makes Bees Drop Off Its Babies. (Page Embry, Entomologytoday)

Do Pollinators Prefer Dense Flower Patches? Sometimes Yes, Sometimes No. (Andrew Porterfield,

Moss in lawn – OSU

VIDEO: Managing Moss in Lawns. (Alec Kowalewski, OSU)

Where Giant Honey Bees Rest Their Wings During Annual Migration. (Ed Ricciuti,

This Insect Has The Only Mechanical Gears Ever Found in Nature.  “The small hopping insect Issus coleoptratus uses toothed gears on its joints to precisely synchronize the kicks of its hind legs as it jumps forward.” (Joseph Stromberg,

VIDEO: Watch roots from different plants compete for prime real estate underground.  Mathematical modeling and greenhouse studies show complex interactions keep roots productive. (Elizabeth Pennisi,

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

Floribunda Rose ‘Mardi Gras, Oregon State University

Plant lists that shouldn’t exist. (Linda Chalker-Scott, WSU;

The contrarian rosarian–debunking rose mythology. (Jim Downer, U of CA;

Why insects are more sensitive than they seem. (Zaria Gorvett, BBC)

NEW PUBLICATION: A PNWBBA Guide to Habitat Management for Bumble Bees in the Pacific Northwest. (Downloadable PDF) (Rich Hatfield, Kurt Merg, and Joel Sauder, Xerces Society)

NEW PUBLICATION: The Pacific Northwest Bumble Bee Atlas: Summary and Species Accounts-A collaboration between the Xerces Society, Idaho Department of Fish and Game, and Washington Department of Fish and Wildlife. (Downloadable PDF) (Rich Hatfield, Leona Svancara, Leif Richardson, Joel Sauder, and Ann Potter; Xerces Society)

Honey bee in flight in front of honeycomb.
Honey bee. Photo: Lynn Ketchum © Oregon State University

Genetic Analysis Reveals the Origins of the World’s Most Common Honeybee Species.  “The western honeybee hailed from western Asia seven million years ago, ending the contentious debate over where these buzzy critters originated.” (Rasha Aridi,

Myth Busting for Extension Educators: Reviewing the Literature on Pruning Woody Plants.
(Linda Chalker-Scott, WSU & Jim Downer, U of CA; Journal of the NACAA)

Prevalence of Different Horticultural Taxa of Ivy (Hedera spp., Araliaceae) in Invading Populations. “‘English’ ivy (Hedera spp.) is a complex of invasive plant pests that are separated into several distinct taxa. To better understand the invasion by ivy of Pacific Northwest native forests, we investigated the taxonomic identity of 58 selected invasive populations in the Pacific Northwest.” (Midori M. Clarke, Sarah Reichard, Clement W. Hamilton; via

Dorsal view (above) Giant Hornet, with wings spread
Giant Hornet – Oregon Department of Agriculture

Symptoms and Signs for Plant Problem Diagnosis – An Illustrated Glossary.  A great resource for diagnosticians! (Janna Beckerman and Tom Creswell, Department of Botany and Plant Pathology, Purdue University)

“Your Christmas tree may be adorned with lights and glitter. But 25,000 insects, mites, and spiders are sound asleep inside the tree.” (University of Bergen via

Why Giant Hornets Rub Their Abdomens on Beehives Before Attack. (Paige Embry,


Basics of Tree Identification-Twigs (Mo_Plant_Daddy_ via

Basics of Tree Identifcaiton-Leaves (Mo_Plant_Daddy via

Binomial Nomenclature: sp. vs. spp. (Mo_Plant_ Daddy via

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

Hemlock trees
Western hemlock trees – OSU

Pruning Established Trees. (Jim Downer,

The Northeast’s Hemlock Trees face extinction.  A tiny fly could save them. (Zoya Teirstein,

Back-Seat Driver: The Parasite That Makes Bees Drop Off Its Babies. (Paige Embry,

VIDEO: Born Pregnant: Aphids Invade with an Onslaught of Clones. (

Honey bee flying in front of honeycomb
Honey bee – OSU

Are the honeybees raised in urban environments beneficial or detrimental?  As a native species.
(Jeanine Farley,

MORE ABOUT BEES…The Truth About Honey Bees.  “Raising nonnatives does not “save the bees”—and may harm them.” (Laura Tangley,

Garden Logic – understanding correlation and causation in our gardens and landscapes (Linda Chalker-Scott, WSU)

Prion-like protein acts as water sensor in seeds. (Jyoti Madhusoodanan, PNAS .org)

Pitcher Plant Moths and their Pitcher Plant Homes. (

Jumping spider
Jumping Spider

Spiders on Tiny Treadmills Give Scientists the Side-Eye.  “Jumping spiders see more in their periphery than previously known.” (Maddie Bender,

MORE ON SPIDERS…Spiders are much smarter than you think.  Cognition researchers are discovering surprising capabilities among a group of itsy-bitsy arachnids.” (Betsy Mason,

Beetle Proves It’s Possible To Survive Millions Of Years Without Having Sex. (Rachael Funnell,

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

Rooting around- the differences between taproots and mature roots. (Linda Chalker-Scott, WSU via

Is your Landscape Sustainable? (Jim Downer,

Water, water, everywhere.  Learn an easy trick to determine soil moisture. (Sylvia Thompson-Hacker,

Container pots with vegetables and herbs, growing on a patio.
Container garden. Photo from Flickr by Wendy Cutler

Contain Yourself: Vegetable gardening in containers and small spaces. (John Porter,

How do we know which invasive plant pests will be the next big threats? (Rosyln Noar, et al,

Signs and symptoms of plant disease: Is it fungal, viral or bacterial? (Jim Isleib, Michigan State University Extension

Diagnosing Sick Plants. (Sarah D. William, et al, Ohio State U)

20 Questions on Plant Diagnosis. (Joy Bogg, et al, Ohio State U)

Wasps are valuable for ecosystems, economy and human health (just like bees.) (UCL)

Bumble bee on purple clover blossom.
Bumble bee on clover blossom. Photo: Lynn Ketchum, Oregon State University

Bumble bees damage plant leaves and accelerate flower production when pollen is scarce. (Foteini G. Pashalidou et al, via

Ancient Wollemi Pines Resurgent.   “Ten years after its discovery, a vanishingly rare tree from the Cretaceous Period is a scientific darling and may soon become a commercial success too.” (Stephen McLoughlin & Viva Vajda,

Plants Grown in Containers Course: Online (FREE and at your own pace course.) (NCSU)

The DNA of lettuce unraveled: in 6000 years from weed to beloved vegetable. (Wageningen Plant Research)

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

An Unusual Tree Company- Bartlett Tree Experts.  “In addition to providing tree services, this company also maintains the Bartlett Tree Research Laboratories and Arboretum. The latter includes over 300 acres of tree collections and ongoing research trials.  Here’s a sampling of the tree research…” (Linda Chalker-Scott,

Field bindweed, Oregon State University

Bidding goodbye to the dreaded Bindweed-The white, trumpet-shaped flowers called bindweed that seem to bloom everywhere can be one of the most frustrating weeds for home gardeners.” (Andy Hulting, OSU)

Millipede Swarms Once Stopped Japanese Trains in Their Tracks.  “A team of scientists say they have figured out the cicada-like life cycles of the many-legged arthropods.” (Veronique Greenwood,

Leave Your Lawn Alone! (Linda Chalker-Scott, WSU)

My Soil is Crap-Part II. (Jim Downer,

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

Revised publication: How to Control Slugs in Your Garden.  Practical tips on how to deal with slugs in your garden, given in both English and Spanish. (EM 9155-Neil Bell, Amy J. Dreves, OSU)

“Can we just quit with the vinegar-epsom salts weed-killer nonsense?  It doesn’t matter how safe it sounds if it doesn’t work.”n(Ohio State University Extension)

Soil bacteria could improve crop yields, via fungi (Michael J. Hass, Cornell University)

Rose leaves with viruses. Leaves are speckled with pale yellow spots.
Rose virus. Photo: Jay Pscheidt, OSU

NEW SECTION IN THE PNW HANDBOOK: Plant Viruses: Dead or Alive? (Jay Pschdeidt, OSU)

Dirty Dozen? Not so fast… Each year, the Environmental Working Group (EWG) issues a list of foods – the so-called ‘Dirty Dozen’ – which it considers to have the highest pesticide residues.  (Cornell University)

This robot uses AI to pollinate greenhouse tomatoes. (

Handful of soil.
Soil. Photo: OSU

My soil is crap. Or is it? (Jim Downer, Garden

Bizarre ‘worm tornado’ in New Jersey has scientists baffled. (Mindy Weisberger,

The AAS (All-America Selections) judges pick their favorite plants. (All-America selections.org_

To mulch or not to mulch? It shouldn’t even be a question. (Linda Chalker-Scott, WSU)

Understanding mysteries of plant diseases: Diagnosis and Detection (Part 2 of 3 in this blog series)- Something is wrong? (Jim Dower, Garden

Strawberry plant with ripe strawberries.
Strawberries. Photo: Bernadine Strik, OSU

Watch the Video! -The Uncommon Berry Patch.  A presentation that covers some less-commonly grown berries for the home garden as well as some native fruits found in western Oregon. (Neil Bell, Dr. Bernadine Strik, OSU)