Natter’s Notes
Jean R. Natter, OSU Master Gardener

Ants! They’re players in perhaps one of the oldest good-news-bad-news stories ever.

The good news is that ants are valued for their beneficial activities. They add large quantities of spent plant and animal remains into the soil as they cultivate and aerate the soil. They also create channels for water and roots. They’re predators, too, and are members of nature’s clean-up crew, carting away debris that includes stray crumbs and dead insects.

The bad news is that ants sometimes get carried away. If they aerate the soil in and around a rootball excessively, water passes through the soil too rapidly to soak in, the plant wilts, and may die. Then, too, people take a dismal view of their uninvited excursions indoors when they trail across the floor, headed for wayward crumbs or the pet’s dish.

The preferred method to “get rid” of ants is to use a commercially formulated ant bait. The ants feed on the bait, then carry some back to the nest to share with the family. 

It’s critical to understand the meaning of “I want to get rid of ants; permanently” And they want it now! For the pest control professional, it’s we’ll stop them now, then we’ll return when they do.”

Here’s where Master Gardeners have a stellar opportunity to share a “teachable moment” during which they help a client, neighbor, or friend, understand the true outcome of managing house-invading ants. To be blunt, one can only stop the influx temporarily, until the next time. 

Too often, people will only spray the visible ants in hopes of stopping the invaders. Unfortunately, applying that spray wastes time, money, and effort. It only affects the visible ants, a mere 10 percent, or less, of the nest’s population.

Whenever people report they have “sugar ants,” it’s likely they have odorous house ants, Tapinoma sessile. They’re just an 1/8-inch, and dark brown to shiny black. A quick and-dirty method to quickly verify their ID is to squash one or two. Then, they emit a distinctive, unpleasant odor which has been variously described as rotten coconut or petroleum-like.

Fig 1. Odorous house ant, Tapinoma sessile, feeding at a liquid commercial ant bait such as Terro. Whitish objects are ant pupae, the life stage between larva and adult.
Fig 1. Odorous house ant, Tapinoma sessile, feeding at a liquid commercial ant bait such as Terro. The whitish objects are ant pupae, the life stage between larva and adult. (

Effective baits for odorous house ants include Terro (a borate-based liquid) and Combat (a gel with fipronil). I keep a 2-oz bottle of Terro on hand because odorous house ants are very persistent little fellows; they will return, repeatedly through the year. Common events that tend to trigger an invasion at my place include after heavy rains; following a serious cold spell; and during summer’s heat. Sometimes, I wonder if they’re just in the mood.

After bait is set out, monitor activity. Add fresh bait as long as the ants stream in. It may take weeks until the foragers stop feeding. If they’re still going strong after 3 weeks, try another bait, this time with a different active ingredient, perhaps hydramethylnon or indoxacarb.

Frankly, everyone must discard their fantasies about eradicating ants. The more accurate strategy, although it may be far less satisfying, is to make a plan to limit the indoor invaders.

Odorous house ants, Tapinoma sessile, are probably the most common house-invading ants across the country. They’re small, dark brown or black ants, 1/16- to 1/8-inch long, with the usual 3 body parts of an insect – head, thorax, and abdomen. The characters which define them as ants are a petiole (a narrow connection between the thorax and abdomen) and two elbowed antennae. The characteristic which differentiates them from other ants is that their single petiolar node is very small and hidden by the abdomen. Then, too, when they’re crushed, they smell bad. Some people say the rather penetrating odor is similar to petroleum or rotted coconut.

Illustration of odorous house ant, Tapinoma sessile; lateral view. A key identification character is the small petiolar node hidden by the anterior portion of the abdomen.

Fig 2. Odorous house ant, Tapinoma sessile; lateral view. A key identification character is the small petiolar node hidden by the anterior portion of the abdomen. (

An odorous ant colony is relatively small, to about 10,000 individuals, with multiple queens. Nests are usually outdoors just below the soil surface, underneath pavers, wood piles, or other debris. But nests may also be indoors, in a wall void or near warmth-emitting sources.

Odorous house ant populations enlarge by one of two methods: mating of winged reproductives or via budding of the colony. Budding occurs when a hundred or so workers transport several of the colony’s queens to a new site. With time, a series of closely related, cooperative colonies forms — a supercolony. No wonder we can’t eradicate ants!

Managing ants requires a multi-pronged approach.

1. Sanitation (clean up regularly), and store perishable foodstuffs in tight, rigid containers.

2. Caulk and seal cracks in the foundation or gaps where utilities enter structures.

3. Manage honeydew-producing insects on landscape plants: mealybugs, whiteflies, as well as both soft and cottony scales.

4. Use commercially-formulated ant baits, refreshing the bait as needed until the foragers stop coming, perhaps as long as 3 weeks.

5. Keep a supply of effective bait on hand to use the next time the ants return!

Ant baits act slowly because the foragers share with other ants within the colony. If a bait is ineffective after several weeks, switch to one with a different active ingredient.

Commercial baits are formulated such that the foragers will survive long enough after feeding that they have sufficient time to carry bait home to colony members. (Editor’s note: Recall that Master Gardeners do not suggest home remedies.) When it comes to odorous house ants, have bait at hand so that you can rapidly respond to their subsequent invasions.


Identification and habits of Key Ant Pests in the Pacific Northwest (

– “5 Most Common Ants in the Home”-– Ants:

– Odorous House Ant Identification Resources  –

– “Don’t Let Ants Come Over Uninvited: Pavement Ants and Odorous House Ants” –   Both ants are similar, about 1/8-inch long and a brown-black color. The main difference is that odorous ants have one petiolar node whereas pavement ants have 2. (See Figure 2, above.)

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

Cupped hands holding soil.
Photo Oregon State University

Some domesticated plants ignore beneficial soil microbes.  “Domestication yielded bigger crops often at the expense of plant microbiomes.” (Holly Ober, U of CA Riverside)

Your new word for the day: thigmomorphogenesis:  “… thigmo-” which means touch, “-morpho-” which means appearance, and “-genesis” which means beginning. String them all together and you get the phenomenon seen when plants respond to mechanical stimulation by changing their growth pattern and hence the way they look.” (Dr. Linda Chalker-Scott, The

Blooms and Borders: How Daffodils Reveal Historic Building Foundations (Sherry Teal, Southern Ramble)

Researchers Turn Spinach Leaves Into Beating Heart Tissues. “These living leaves could eventually become patches for the human heart.” (Jason Daley,

Many plants have extrafloral nectaries helpful to beneficials. (Russel F. Mixell, U of Florida)

Plants, Pollen and Allergies.Plant allergies are complex. Chief among allergies are allergies to pollen but not everyone reacts to pollen or the same pollen. Some people may also react to touching a plant or odors given off by a plant that have nothing to do with pollen. A medical allergist may be needed to help identify which specific allergens one needs to avoid.” (Missouri Botanical Garden)

Base of large, mature tree, with many exposed tree roots, above the soil level.
Photo Oregon State University

A root’s life. “Roots are the unsung heroes of plants! But unfortunately your every day hard working root gets little respect from gardeners.” (Jim Downer,

The life and death of one of America’s most mysterious trees. “A majestic ponderosa pine, standing tall in what is widely thought to have been the “center of the world” for the Ancestral Puebloan people, may have more mundane origins than previously believed…” (Daniel Stolte, University of Arizona)

Planting Prognostication: Understanding last frost and planting dates.  “Except for areas of the US that are more tropical like southern Florida or Hawaii, most gardener’s planting schedules are set around winter weather and the possibility of frost or freeze.  And even for gardeners in those more tropical areas, planting sometimes needs to be planned to schedule around the extreme heat of summer.  Understanding these planting times can really lead to success or failure, especially for vegetable gardens, tender annuals, tropicals, and non-dormant perennials.” (John Porter,

Revised publication: Growing Blackberries in Your Home Garden. (Bernadine Stik, Cassie Bouska & Emily Dixon, OSU; EC 1303)

Revised publication: Growing Raspberries in your Home Garden.(Bernadine Strik, Cassie Bouska, & Emily Dixon, OSU; EC 1306)

Revised publication: Growing Strawberries in Your Home Garden.(Bernadine Strik, OSU; EC 1307)

Cover of Pantry Pest Guide

New publication: PANTRY PEST GUIDE- Common Insect Culprits in Homes and Kitchens of the Pacific Northwest. (PNW Extension Publication 729)

WSU publication: GROWING ROSES IN WASHINGTON STATE- COMMON DISEASE AND INSECT PROBLEMS. (Marianne Ophardt & Sheila Gray, WSU, PNW Extension Publication 733)

New publication:  The Care and Maintenance of Wood Shingle and Shake Roofs. (J. Morrell, J. Cappellazzi and J.W. Pscheidt, PNW Extension Publication 733)

Hand holding small orange flower with green foliage and sunlight in the background.
Image: Pixabay

The glory of gardening: hands in the dirt, head in the sun, heart with nature. To nurture a garden is to feed not just on the body, but the soul.

Alfred Austin

Caring and Commitment to our Community

We hope this finds you taking good care, finding time to nurture a garden, or discovering respite in spring delights like cherry blossoms, busy mason bees, and bursting tulips.  In the midst of these uncertain times, one thing we know for sure is that metro area Master Gardeners are a committed and caring group who serve their community in so many ways. 

Image: Pixabay

Although Master Gardener in-person activities are suspended, due to the pandemic, Master Gardeners are still contributing to their community.  We know of Master Gardeners growing vegetable starts for their neighbors, sewing masks, buying flowers to add cheer to those in senior centers, funding the purchase of vegetable starts for agencies serving those experiencing food insecurity, growing extra vegetables and fruits to donate to area food banks, and reaching out to fellow volunteers to check on their well-being.  Master Gardeners are also serving as dedicated front-line essential workers, working from home, managing home schooling, caring for family members, and lending a helping hand to neighbors.  Such care and efforts are not surprising, but are confirmation of a valuable and committed community! 

Metro Master Gardener Program Goes Online!

With the goal to keep our Master Gardener community connected and engaged, the metro Master Gardener program has moved online.  Every Friday at 1pm we are presenting a horticulture-focused webinar for Master Gardeners and the gardening public. 

Upcoming webinars in May…

Freshly harvested beets and carrots, still speckled with soil, lying on wood counter top.
Image: Pixabay
  • 1PM, Friday, May 8th, Fundamentals of Lawn Care, with Weston Miller, OSU Extension
  • 1PM, Friday, May 15th, Practical Garden Food Safety: best practices for the edible garden, with Sara Runkel, OSU Extension
  • 1PM, Friday, May 22nd, TBA

Metro Master Gardener online webinars count as continuing garden education credit.

To register for upcoming webinars, watch for a weekly email sent from Marcia McIntyre that has a link to the Zoom registration page.  Links to the webinars will also be posted on our Facebook and Twitter accounts.

Webinar Recordings
Do you have a schedule conflict with an upcoming webinar?  Don’t despair.  We are posting recordings of our webinars a few days following the presentation.

Check out past webinars here:

Master Gardener Hangout!

Brown leather boots sitting on lawn, planted with white daisy plants.
Image: Pixabay

Are you looking to connect with other Master Gardeners in an informal, online setting.  Join our Friday, Master Gardener Hangouts.  This is a forum to talk all things gardening. 

Past Master Gardener Hangouts have been fun, with mini tours of gardens, as participants took their laptops and phones out into their gardens – shared favorite vegetable varieties – asked each other questions – just enjoyed a chance to connect with fellow gardeners! 

You can connect via phone or internet. Look for an email from Marcia McIntyre, that will be sent on Friday afternoons as that week’s webinar is ending,with a link to join the ‘Master Gardener Hangout’.

Master Gardener In-person Activities Suspended

As announced in March, due to the evolving COVID19 situation, all Master Gardener volunteer activities are cancelled or postponed until further notice. This includes all Master Gardener clinics (phone, Farmers Markets, and special events), classes, workshops, demonstration gardens, Speakers Guild presentations, fundraisers, and in-person meetings/lectures/speakers.  In addition, our Spring Recertification event scheduled for Saturday, May 16, is cancelled.

OSU Extension Service is working to make communities safe.  As OSU provides more guidance, we will provide updates. 

Orange OSU Master Gardener icon.

With the cancellation of volunteer activities, and knowing the many challenges people are facing, we are waiving volunteer requirements for 2020.  We ask metro area Master Gardeners to report any volunteer hours served this year and their continuing education hours, by September 30, 2020.

We encourage Master Gardeners to take advantage of the many online continuing education opportunities.  Updates will be sent via email and/or posted in this monthly newsletter.

Thanks for Sharing Your Expertise!

Plant in small pot with a hand written piece of paper that says 'Thank you'.
Image: Pixabay

The dedication and generosity of the Master Gardener community is always an inspiration.  This generosity was apparent as we made a swift pivot to offer garden education opportunities online.  We are incredibly grateful to Dennis Brown, Eric Butler, and Claudia Groth for so quickly stepping up to share their expertise and knowledge as we kicked off our webinar series.  Thank you all, for your kind generosity!

OSU Online Insect Agroecology Course

Bee gathering pollen on cherry blossoms.
Image: Pixabay

Last month Dr. Gail Langellotto, professor, Oregon State University, and Statewide Master Gardener Program Coordinator gave access to a valuable continuing education opportunity for OSU Master Gardeners.

Gail made recordings of her Entomology/Horticulture (Insect Agroecology) University course available for Master Gardeners to view.  The class delves into ecological theory, and considers how this theory applies to the design and management of sustainable agroecosystems.  She shared the first two lectures in April: ‘The Importance of Insect Diversity’ and ‘Bottom Up Regulation of Herbivores (Plant Nutrition)’

You can view the remaining course lectures at the link below.

Oregon State University – ENT/HORT 444/544 (Insect Agroecology)

Time spent viewing the lectures counts as continuing education hours for perennial Master Gardeners.

More Continuing Ed Opportunities from OSU Extension and our Partners

Below are some great continuing education opportunities offered by OSU Extension programs and partner organizations. Be sure to read weekly metro MG program emails for opportunities that arise during each month.

Sunlight streaming through tree trunks in forest.
Image: Pixabay

Tree School Goes Online – FREE!
You still have time to take part in this 15-part series from Clackamas Extension Service Forestry and the Partnership for Forestry Education. Recordings are posted following classes.

Master Gardener Advanced Training Webinars
Next up: Winter Squash Research at OSU, with
Dr. Alex Stone and Lane Selman

Metro area Master Gardener – Native Bee Survey Training
with Andony Melathopoulos, OSU

Tuesday, May 5, 1pm to 4pm

Metro (regional government) Garden Design for Wildlife
Wednesday, May 13, 3pm to 4:30pm
Register here. A subsequent webinar on the same topic will be offered in Spanish upon request

May Garden Checklist

Our May garden checklist encourages you to weed, weed, weed, plant perennials and check your soil temp!