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.