Wildfire smoke and bonsai

For those of us on the west coast that aren’t directly in harms way of the many fires, we are still affected by the horrendously bad air and smoke. My heart goes out to those who were more directly affected by the fires and I hope everyone closer to the fires stays safe.

AQI in Portland, and most of western Oregon has been between 300-500 for the past week or so, with elevated levels of NO2, SO2 and CO along with the particulate matter.

Is anyone noticing anything funny with their trees? It seems like a lot of my plants are going dormant, with some of the deciduous even losing leaves. It’s a little early for fall leaf drop, but I’m wondering if the lack of sunlight is causing the plants to shut down early. Transpiration is definitely way down across the board right now, and watering has slowed down a lot (just as things were starting to pick back up for fall).

I’m guessing I’ll need to provide extra protection this winter if nothing else.

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Same here. My deciduous trees either is in fall colors or has dropped their leaves.

I live south of Issaquah,WA

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Definitely seeing slower water usage and some leaves on deciduous trees starting to turn, which is happening to the landscape trees not just my bonsai. What concerns me most is we’re supposed to have an extra wet, cold winter this year so I’m really concerned with disease and root rot.

I saw the same thing and am thinking that is the tree’s response to less light. They have already been primed to go into winter as we approach the fall solstice and the dramatic drop in light was their signal that is time to go the rest of the way. The good news is that it looks like we are going to be getting some rain and the smoke should clear a fair bit this weekend.

I am in Southern California (Orange County) and the air here is horrible. My deciduous conifers (Bald Cypress and Dawn Redwood) seem most affected as they have begun shedding their leaves. My deciduous oak and elm don’t seem affected yet. Climate change is here to stay unless we act!

I’m curious if the plants are seeing much light at all. This is not totally scientific, but my transitions glasses are not really triggering when I go outside, leading me to believe that even the light that is making it through the smoke & haze is not usable for photosynthesis.

During one of the bad days I think I saw a UV index of 0 or 1 on my phone app. Right now it is 2 with a AQI of 166 and visibility of 3 miles. So my guess is that the light that is making it through is not very photosynthetically efficient.

Will acid rain be a concern with the early rainfalls?

Wood ash is typically alkaline so I would assume it might actually raise the pH slightly rather than lower it. Either way, pH changes are never a fun thing to deal with in the container.

Weather over the past month in the San Jose area went from 108 degrees to smokey 90’s back to 100’s and smokey 80-90’s. I’m seeing the same thing with most of my deciduous (including Dawn Redwood) dropping leaves and transpiring less. Interestingly, I have an Coast Live Oak looking tree that has just exploded in the last two weeks–6-10" shoots. Several trees are also sending out a new flush of growth. The sky was clear today, but it sure felt like fall. Interesting times.

And as a side note, when the air was the worst, we had around 50 hummingbirds performing aerial combat around our four feeders…that’s at least 3 times what we normally had. About 30 have stuck around.

I wasn’t planning on a full defoliation in mid-September, but the leaves all died with the wind and smoke cover. The buds look strong and I think they are going to push a new flush of growth :grimacing:

I’ll wait and see and if it does push more growth, I’ll baby it over the winter. The tree is a 3 year old yard donor (silver birch I think), and is super strong so I think it’ll be okay in the long run.


My small Littleleaf Linden does this, third year. Just cut off the (not green) leaves and stems. I left any green parts. Month untill first freeze. Doesnt push until spring.

Also a habit for my small Hazelnut.

It did hit 40F here last week. Tops of my squash plants turned black… I guess summer is officially over!

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I really don’t envy you over the pond at the moment. Fires on one side of the country, hurricanes on the other. May God bring you all through safely…

Rain has cleaned the air in the PNW but I was told that the wildfire smoke is now affecting Europe.
Any problems in the UK?