The annual Growing Gardeners Conference offered a wide variety of interesting topics to learn about this year. Here are some notes from a few of the presentations.

What Does Climate Change Mean for Gardeners? Keynote speaker Philip W. Mote

Philip Mote (@pwmote) discussed climate change and its impacts on gardeners and gardening in the Pacific Northwest. Philip is the director of the Oregon Climate Change Research Institute (OCCRI) and a professor in the College of Earth, Ocean, and Atmospheric Sciences. OCCRI is a network of over 150 researchers at Oregon State University (OSU), the University of Oregon, Portland State University, Southern Oregon University, and affiliated federal and state labs. All are doing important research focused on Climate Change in Oregon and the Northwest. Here is a link to the website:

-Humans ARE changing the climate.

-Over the past 200 years CO2 levels have increase dramatically, all due to burning fossil fuels. We would have to reduce emissions by 80% by 2100 to stabilize greenhouse gases.

-Unfortunately, CO2 acts as fertilizer for invasive weeds. 

-Oregon was one of the first states to set greenhouse gas reduction goals but will miss its 2020 target.

-Overall temperatures in the NW have increased by 2 degrees F.

-In Oregon 2015 was recorded as being the warmest year on record, breaking the previously warmest year of 1934. 2016, 2015 and 2014 all recorded record high temperatures as well.  2018 looks to be moving in the same direction!

-The last freeze of spring is becoming earlier and the first frost of fall is later.

-As we move into the future hardiness zones will inevitably shift if as a planet we don’t reduce emissions and stabilize greenhouse gasses.

Organic Pesticides for Home Gardeners presented by Kaci Buhl

Kaci gave an excellent, fun, engaging presentation that provided everyone the opportunity to learn more about the wide variety of organic pesticides available for home gardeners. 

-Pros & cons of glyphosate were discussed. It is widely suggested that glyphosate is a probable carcinogen; but recent studies have shown that cancer risks are no higher when used at the standard recommended levels of application.  Roundup is now available in some new formulations such as Roundup for Lawns that do not contain glyphosate.

- Use of Vinegar/Soap formulations for organic weed control. Many variations are widely circulated online. These recipes often offer unclear dosages and have unclear effectiveness. Some recipes utilize salts which can have negative effects on soil fertility. 

- Just because something is labeled “natural” or "organic" does not mean it is completely safe. For example: mint oil, sulfur, copper sulfate, botulism, tigers(!)

-Sulfur is the most widely used organic pesticide

- Even though a pesticide may be OMRI approved, it must be used as its label dictates. The label is still the law! Some organics can be harmful to pollinators, aquatic invertebrates, or terrestrial arthropods. Don’t forget to recommend wearing protective clothing & goggles when speaking with the public.

-Kaci spent some time demonstrating how to navigate the extremely useful website PICOL (Pesticide Information Center Online) to search for currently registered products that meet OMRI standards for organic production.  This Northwest database was created and developed by WSU and is an excellent resource for locating up to date information about organic pesticides. Follow this link to check it out! Pesticide Information Center Online

-Carbon dioxide (CO2) given off by dry ice is currently being researched and looks promising to be a safe and humane method of euthanasia for use with rodents. These products have not been evaluated for organic production yet. Stay tuned!

- Spinosad is a newer "organic" pesticide derived by bacteria that may be tried on some pest species resistant to other pesticides. 

-An entertaining website that illustrates how familiar (benign) things can become alarming and cause misplaced fears when presented in an exaggerated, sensational manner:



Slime Time- Slug & Snail ID, Biology & Management presented by Rory McDonnell  

Rory McDonnell gave a truly delightful presentation on a common, not so delightful pest we have all come across in our gardens. 

-Novel slug repellents are continually being researched. Studies have shown that slugs are very attracted to the odor of cucumbers, thus work is being done to chemically recreate that smell for use as bait. Clove oil is also being studied and has proven effective, but is expensive and correct percentages need to be determined as it can damage plant roots when used at high strength. Nemaslug Nematode is widely used in Europe, but is still not available in the US. As with all research for pesticides, care must be taken to not kill our native slug species.

-Slugs can move through spaces as small as 2mm

-Slugs and snails can vector pathogens such as E. Coli

Giant african snails can carry rat Lungworm

Giant african snails can carry rat Lungworm

-Rat Lungworm is a parasitic nematode with a complicated life cycle, part of which requires living inside snails and slugs. Human infection by this parasite is considered an emerging infectious disease. The range and incidence of the disease are expanding throughout the tropics and subtropics, including in the Hawaiian Islands, but it is also expected to move to the US.  Rory was interviewed for this (somewhat horrifying) article in a 2017 New Yorker issue.  




To learn more about Pacific Northwest slug identification, damage, management and research visit these online resources- 

Click here to go to the Slug Portal website. 

Pacific NW Nursery IPM Slug & Snail page.

Click here for the ODA Slug & Snail Guide.

You can also follow Rory on twitter @roryjmcdonnell