Here’s the narrated lecture for the Biotic Plant Problems session. This was developed for the 2016 Lane County Master Gardener’s Plant Diagnostic Specialist training and is a complement to the Abiotic training session.
Slides and resources from my presentation to the OSU Extension Multnomah County Master Gardeners. Covered an overview of climate change and how that can affect the phenology of garden plants as well as changing pest pressures.
Citizen Science on Plant Phenology:
Follow-up on audience questions (if I missed one, just click ‘leave a reply’ above)
Is there a list of ash tree alternatives? Choose anything but ash (Fraxinus sp.) to avoid loss to Emerald Ash Borers. Good general source of information: http://www.emeraldashborer.info Local training from OSU Extension on potential invasive insects affecting trees: http://pestdetector.forestry.oregonstate.edu/programs/registration-and-online-course
What to spray to treat Azalea Lace Bug? http://insect.pnwhandbooks.org/hort/landscape/hosts-and-pests/azalea-rhododendron-azalea-and-rhododendron-lace-bug Robin Rosetta with the OSU Extension Nursery IPM program has indicated that the nymphs are emerging. This stage in the life cycle is especially vulnerable to contact insecticides (this is different from the systemic insecticide that the questioner mentioned). Labeled insecticidal soaps and neem-based products may be a good choice. Good coverage of the underside of leaves will be necessary.
Recent change in USDA Hardiness zones-does that indicate global warming? “Climate changes are usually based on trends in overall average temperatures recorded over 50-100 years. Because the USDA PHZM represents 30-year averages of what are essentially extreme weather events (the coldest temperature of the year), changes in zones are not reliable evidence of whether there has been global warming.” From: http://planthardiness.ars.usda.gov/PHZMWeb/AboutWhatsNew.aspx