Tom Kimmerer, PhD
@tomkimmerer.bsky.social
I am a forest scientist, botanist, tree physiologist writing about relationships between trees and humans including climate change. A Fulbright Scholar, Author of Venerable Trees and books in progress. Read about trees here: https://ourtrees.substack.com.
Farewell pennies. I have fond memories of pennies in threes. At my elementary school, lunch was free but a 1/2 pint of milk was 3¢. And is it really lunch without milk? My classmates and I carried a few extra pennies in our pockets so that kids who lacked pennies could get their milk too.
November 14, 2025 at 4:38 PM
Farewell pennies. I have fond memories of pennies in threes. At my elementary school, lunch was free but a 1/2 pint of milk was 3¢. And is it really lunch without milk? My classmates and I carried a few extra pennies in our pockets so that kids who lacked pennies could get their milk too.
I love fresh pawpaw, but my kids did not. For them, I made pawpaw cake, which they loved.
October 22, 2025 at 2:06 PM
I love fresh pawpaw, but my kids did not. For them, I made pawpaw cake, which they loved.
Yesterday brought us 5.19" of rain, putting it in the top 10 rain days. This did not come in a storm, but in a steady soaking rain. Increased rainfall and heavier rain events is a result of climate change in the Bluegrass.
Last night we had a spectacular dense bird migration (yellow on the map).
Last night we had a spectacular dense bird migration (yellow on the map).
October 8, 2025 at 3:17 PM
Yesterday brought us 5.19" of rain, putting it in the top 10 rain days. This did not come in a storm, but in a steady soaking rain. Increased rainfall and heavier rain events is a result of climate change in the Bluegrass.
Last night we had a spectacular dense bird migration (yellow on the map).
Last night we had a spectacular dense bird migration (yellow on the map).
I have always been grateful for rainy days like today. A steady rain brings calm and focus to my thinking and writing. I also enjoy (mostly) working or walking out in the rain.
Here are views from my porch in Borneo (top) and Kentucky (bottom) on nice rainy days.
Do you enjoy rainy days?
Here are views from my porch in Borneo (top) and Kentucky (bottom) on nice rainy days.
Do you enjoy rainy days?
October 7, 2025 at 4:00 PM
I have always been grateful for rainy days like today. A steady rain brings calm and focus to my thinking and writing. I also enjoy (mostly) working or walking out in the rain.
Here are views from my porch in Borneo (top) and Kentucky (bottom) on nice rainy days.
Do you enjoy rainy days?
Here are views from my porch in Borneo (top) and Kentucky (bottom) on nice rainy days.
Do you enjoy rainy days?
Three ginkgo stories coming this weekend at Our Trees.
October 3, 2025 at 4:49 PM
Three ginkgo stories coming this weekend at Our Trees.
Trees are beginning to show their colors, but just as dramatic are our oldfields, producing shades of gold to delight our senses. Follow our Autumn color adventures at Our Trees. ourtrees.substack.com/p/autumn-col...
September 6, 2025 at 5:57 PM
Trees are beginning to show their colors, but just as dramatic are our oldfields, producing shades of gold to delight our senses. Follow our Autumn color adventures at Our Trees. ourtrees.substack.com/p/autumn-col...
I wish I could be in upstate South Carolina today for the Blue Oak Pawpaw Festival. Don't you? www.blueoakhortsc.com/scpawpawfest
August 30, 2025 at 3:15 PM
I wish I could be in upstate South Carolina today for the Blue Oak Pawpaw Festival. Don't you? www.blueoakhortsc.com/scpawpawfest
With the arrival of cool weather, we see early signs of the autumn transition of leaves. It's especially noticeable around accumulated wounds of summer, with yellow patches expanding around old wounds, and yellow to red spots beginning to show in other areas. Chinkapin oak, Quercus muehlenbergii.
August 23, 2025 at 2:11 PM
With the arrival of cool weather, we see early signs of the autumn transition of leaves. It's especially noticeable around accumulated wounds of summer, with yellow patches expanding around old wounds, and yellow to red spots beginning to show in other areas. Chinkapin oak, Quercus muehlenbergii.
This is really offensive. There are worse corporate names, but not many.
July 15, 2025 at 7:36 PM
This is really offensive. There are worse corporate names, but not many.
In our Tree Story about pawpaw, we discussed how difficult it is to manage fresh fruit. The brewery industry has discovered the benefits of frozen pawpaw fruit, and there are not many pawpaw brews available. Have you tried any?
ourtrees.substack.com/p/tree-stori...
ourtrees.substack.com/p/tree-stori...
July 11, 2025 at 2:07 PM
In our Tree Story about pawpaw, we discussed how difficult it is to manage fresh fruit. The brewery industry has discovered the benefits of frozen pawpaw fruit, and there are not many pawpaw brews available. Have you tried any?
ourtrees.substack.com/p/tree-stori...
ourtrees.substack.com/p/tree-stori...
I have seen several stories about how poor most news headlines are, suggesting a lack of effort. I don’t know, is there something wrong with this one?
July 10, 2025 at 2:48 PM
I have seen several stories about how poor most news headlines are, suggesting a lack of effort. I don’t know, is there something wrong with this one?
It's a fine day to be an old tree, like this bur oak near Nashville, TN. Not too hot, plenty of soil moisture, slightly cloudy, a perfect day for a tree. Perhaps for us as well.
July 10, 2025 at 12:34 PM
It's a fine day to be an old tree, like this bur oak near Nashville, TN. Not too hot, plenty of soil moisture, slightly cloudy, a perfect day for a tree. Perhaps for us as well.
We discussed The Summer Flush of growth and climate change. I mentioned that this can happen in entire stands of trees. This hackberry stand (Celtis occidentalis) in an urban park is producing a summer flush across all the tree crowns. Have you seen this?
ourtrees.substack.com/p/the-summer...
ourtrees.substack.com/p/the-summer...
July 9, 2025 at 2:43 PM
We discussed The Summer Flush of growth and climate change. I mentioned that this can happen in entire stands of trees. This hackberry stand (Celtis occidentalis) in an urban park is producing a summer flush across all the tree crowns. Have you seen this?
ourtrees.substack.com/p/the-summer...
ourtrees.substack.com/p/the-summer...
We are beginning to see a phenomenon that used to be rare in our forests, but now is an annual occurrence: recurrent flushing, with new foliage that is often pale. More on this coming this afternoon.
July 8, 2025 at 1:47 PM
We are beginning to see a phenomenon that used to be rare in our forests, but now is an annual occurrence: recurrent flushing, with new foliage that is often pale. More on this coming this afternoon.
One advantage of a rainy summer such as this one is that rain-spattered leaves shining in the afternoon light are very interesting. From left: Osage-orange, Shumard oak; sweetgum, baldcypress; all found in the Kentucky Bluegrass.
July 7, 2025 at 10:33 PM
One advantage of a rainy summer such as this one is that rain-spattered leaves shining in the afternoon light are very interesting. From left: Osage-orange, Shumard oak; sweetgum, baldcypress; all found in the Kentucky Bluegrass.
The major goal of my career is to enrich our understanding of the lives of tree. Here is the most important sketch of a tree ever made. It is Charles Darwin's first attempt to create a tree of life. He drew this in 1837, 22 years before Origin of Species was published. He wrote "I think" at the top.
July 6, 2025 at 2:03 PM
The major goal of my career is to enrich our understanding of the lives of tree. Here is the most important sketch of a tree ever made. It is Charles Darwin's first attempt to create a tree of life. He drew this in 1837, 22 years before Origin of Species was published. He wrote "I think" at the top.
My city, Lexington, KY, grew in the middle of the Bluegrass woodland pastrure ecosystem, including its ancient trees. Wandering around the city leads constantly to encounters with huge presettlement trees. This beautiful bur oak stands in a parking lot in a busy strip mall.
July 5, 2025 at 6:59 PM
My city, Lexington, KY, grew in the middle of the Bluegrass woodland pastrure ecosystem, including its ancient trees. Wandering around the city leads constantly to encounters with huge presettlement trees. This beautiful bur oak stands in a parking lot in a busy strip mall.
Imagine that there was a US administration whose department heads were competing to see how many people they could kill. It would look just like this one. Rubio and Musk are in the lead, causing thousands of deaths by shutting down USAID. Kennedy is trying to catch up. Trump keeps the leader board.
July 3, 2025 at 3:08 PM
Imagine that there was a US administration whose department heads were competing to see how many people they could kill. It would look just like this one. Rubio and Musk are in the lead, causing thousands of deaths by shutting down USAID. Kennedy is trying to catch up. Trump keeps the leader board.
These are the young fruits of a very important tree. When they are mature later this summer, they will look very different. What do you think they are?*
*Not bananas!
*Not bananas!
June 27, 2025 at 12:22 PM
These are the young fruits of a very important tree. When they are mature later this summer, they will look very different. What do you think they are?*
*Not bananas!
*Not bananas!
I have spent most of my life among the largest and oldest organisms on Earth. One gift of this work is a sense of optimism. With the election of Zohran Mamdani in New York (where I am from), perhaps we can finally begin to restore civil society after the disease of neoliberalism. Let's go!
June 25, 2025 at 12:17 PM
I have spent most of my life among the largest and oldest organisms on Earth. One gift of this work is a sense of optimism. With the election of Zohran Mamdani in New York (where I am from), perhaps we can finally begin to restore civil society after the disease of neoliberalism. Let's go!
In times of trouble and strife, perhaps it is worth listening to Rachel Carson:
“Those who contemplate the beauty of the earth find reserves of strength that will endure as long as life lasts. There is something infinitely healing in the repeated refrains of nature.” Rachel Carson
“Those who contemplate the beauty of the earth find reserves of strength that will endure as long as life lasts. There is something infinitely healing in the repeated refrains of nature.” Rachel Carson
June 24, 2025 at 4:52 PM
In times of trouble and strife, perhaps it is worth listening to Rachel Carson:
“Those who contemplate the beauty of the earth find reserves of strength that will endure as long as life lasts. There is something infinitely healing in the repeated refrains of nature.” Rachel Carson
“Those who contemplate the beauty of the earth find reserves of strength that will endure as long as life lasts. There is something infinitely healing in the repeated refrains of nature.” Rachel Carson
I was going to post more about stress in trees, but I think we've all had enough stress for this weekend. Here instead is a more sooting view of a tree standing alone in a pasture.
June 22, 2025 at 4:40 PM
I was going to post more about stress in trees, but I think we've all had enough stress for this weekend. Here instead is a more sooting view of a tree standing alone in a pasture.
On Juneteenth, let's celebrate Vivien Thomas, a pioneering heart surgeon. A genius surgeon, though lacking a medical degree, he developed new surgeries on animals that were then used on people. I was a young surgical technician at Hopkins and knew who he was, though I never worked with him.
June 19, 2025 at 1:28 PM
On Juneteenth, let's celebrate Vivien Thomas, a pioneering heart surgeon. A genius surgeon, though lacking a medical degree, he developed new surgeries on animals that were then used on people. I was a young surgical technician at Hopkins and knew who he was, though I never worked with him.
The clouds of white dots around lights along the Mississippi River are mayflies emerging from the river. They are keystone organisms, critical to fish and wildlife along the river. But people complain about the nuisance they cause and want them gone. If they go, the life of the river goes as well.
June 18, 2025 at 12:30 PM
The clouds of white dots around lights along the Mississippi River are mayflies emerging from the river. They are keystone organisms, critical to fish and wildlife along the river. But people complain about the nuisance they cause and want them gone. If they go, the life of the river goes as well.