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.
Artists often struggle to represent trees accurately in their work. Fortunately, Leonardo da Vinci showed us how to represent trees. See what he taught us at Our Trees.
Tom Kimmerer (@tomkimmerer)
Artists often struggle to represent trees in a way that looks real. Fortunately, Leonardo da Vinci explained how to represent trees in a way that is true to their nature. He noted, in a series of sket...
substack.com
November 11, 2025 at 10:43 PM
Artists often struggle to represent trees accurately in their work. Fortunately, Leonardo da Vinci showed us how to represent trees. See what he taught us at Our Trees.
Choosing a tree for our homes is one of the joys of the holidays. Here is some guidance about our choices.
Trees for the Holidays
Fetching our Christmas tree was one of the delights of my childhood.
open.substack.com
November 11, 2025 at 8:19 PM
Choosing a tree for our homes is one of the joys of the holidays. Here is some guidance about our choices.
Last night, I watched one of the best nature videos I have ever seen, from Cornell Lab of Ornithology. I have been in love with hornbills since I lived in Indonesia and Malaysia and saw them every time I went out in the jungle.
You really owe it to yourself to watch this.
You really owe it to yourself to watch this.
Islands of the Hornbills
YouTube video by Cornell Lab of Ornithology
www.youtube.com
November 9, 2025 at 4:11 PM
Last night, I watched one of the best nature videos I have ever seen, from Cornell Lab of Ornithology. I have been in love with hornbills since I lived in Indonesia and Malaysia and saw them every time I went out in the jungle.
You really owe it to yourself to watch this.
You really owe it to yourself to watch this.
When I introduce pine nuts, I get three reactions: Oh, I love them; I heard of them but haven't tried them; or what's a pine nut? Find out more at Our Trees.
Tom Kimmerer (@tomkimmerer)
Pine nuts are among the tastiest and most expensive of all nuts. Except that they are seeds not nuts. Pine nuts have an unusual flavor and texture, most people either like them a lot or not at all. Th...
substack.com
November 7, 2025 at 6:32 PM
When I introduce pine nuts, I get three reactions: Oh, I love them; I heard of them but haven't tried them; or what's a pine nut? Find out more at Our Trees.
Our discussion about hazelnuts yesterday reminds me of the very peculiar mutant hazel known as Harry Lauder's Walking Stick. The story at Our Trees tells us why.
Tom Kimmerer (@tomkimmerer)
As a tree biologist, I find odd trees fascinating, especially trees that are shaped differently from others. Sometimes this is due to single-gene mutations. Weeping willows, for example, simply have a...
substack.com
November 6, 2025 at 4:23 PM
Our discussion about hazelnuts yesterday reminds me of the very peculiar mutant hazel known as Harry Lauder's Walking Stick. The story at Our Trees tells us why.
Black walnuts are a North American tree that produces the most delicious nuts of all our tres. Getting the nutmeat out of the fruit is infuriatingly difficult, but there are easier ways to obtain them. More at Our Trees.
Tom Kimmerer (@tomkimmerer)
Black walnut trees, Jugulans nigra, are abundant in much of North America. They are large, distinct trees highly valued for their wood. They bear some of the most delicious but infuriating nuts of an...
substack.com
November 5, 2025 at 3:50 PM
Black walnuts are a North American tree that produces the most delicious nuts of all our tres. Getting the nutmeat out of the fruit is infuriatingly difficult, but there are easier ways to obtain them. More at Our Trees.
Hazelnuts, like pecans, are a great choice for nuts compared with almonds. Grown mostly in the Willamette Valley of Oregon, they are a sustainable crop that uses little irrigation water. And they are delicious. This holiday season, put pecans and hazelnuts on your table and in your kitchen.
Tom Kimmerer (@tomkimmerer)
Hazelnuts are worthy complements to pecans. Today 99%(!) of US hazelnuts are grown in 8 counties of the Willamette Valley in Oregon. The valley provides perfect growing condions, with good soil and ad...
substack.com
November 4, 2025 at 3:20 PM
Hazelnuts, like pecans, are a great choice for nuts compared with almonds. Grown mostly in the Willamette Valley of Oregon, they are a sustainable crop that uses little irrigation water. And they are delicious. This holiday season, put pecans and hazelnuts on your table and in your kitchen.
Consumer choice can play a substantial role in mitigating the climate and biodiversity crises. One important decision is to choose pecans over almonds. Read more at Our Trees.
Tom Kimmerer (@tomkimmerer)
The simultaneous crises of climate change and biodiversity loss have to be addressed at the national and international level, but consumer choice can shift markets in a positive direction. Let’s consi...
substack.com
November 3, 2025 at 5:09 PM
Consumer choice can play a substantial role in mitigating the climate and biodiversity crises. One important decision is to choose pecans over almonds. Read more at Our Trees.
Frankincense and myrrh feature prominently in many religious occassions, including the visit of the Three Wise Men to the Baby Jesus. Read about these amazing tree products at Our Trees.
Tom Kimmerer (@tomkimmerer)
The Three Wise Men brought frankincense and myrrh across vast distances to celebrate the birth of Christ. They also brought gold, which was less valuable.
The dry season in Sudan has begun, so the yo...
substack.com
November 2, 2025 at 8:14 PM
Frankincense and myrrh feature prominently in many religious occassions, including the visit of the Three Wise Men to the Baby Jesus. Read about these amazing tree products at Our Trees.
During the festive period, we use an amazing variety of tree products, ranging from Christmas trees to frankincense. At Our Trees, we will be discussing many of these materials. One that we use a lot of without knowing it is gum arabic, harvested from wild trees and used in a lot of prepared foods.
Tom Kimmerer (@tomkimmerer)
The last two months of the year are filled with festivities. As part of our celebrations, we use a tremendous number of tree products. Some are obvious - Christmas trees, frankincense, cinnamon. Other...
substack.com
November 1, 2025 at 4:51 PM
During the festive period, we use an amazing variety of tree products, ranging from Christmas trees to frankincense. At Our Trees, we will be discussing many of these materials. One that we use a lot of without knowing it is gum arabic, harvested from wild trees and used in a lot of prepared foods.
A beautiful red fir, Abies magnifica, is on a truck making its way from Nevada to Washington to become the US Capitol Christmas Tree, the people's tree at the Capitol, not the white house tree which is not accessible to the public. Learn about its origin and journey at Our Trees.
Tom Kimmerer (@tomkimmerer)
High in the thin cold air of the eastern Sierra Nevada is a band of red fir, Abies magnifica. This year, a beautiful 53 ft. red fir in the Carson Ranger District in Nevada was selected as the US Capit...
substack.com
October 30, 2025 at 5:27 PM
A beautiful red fir, Abies magnifica, is on a truck making its way from Nevada to Washington to become the US Capitol Christmas Tree, the people's tree at the Capitol, not the white house tree which is not accessible to the public. Learn about its origin and journey at Our Trees.
Here is a love story set in the jungles of Southeast Asia. I hope you enjoy it.
Tom Kimmerer (@tomkimmerer)
Here is a love story set in the jungles of Asia. There are a couple of very good videos at the end. This is longer than usual. Please let us know if you like it.
substack.com
October 29, 2025 at 5:52 PM
Here is a love story set in the jungles of Southeast Asia. I hope you enjoy it.
One of my readers asked me whether, in addition to explaining the science of trees, I also hug them. Yes, I do.
Tom Kimmerer (@tomkimmerer)
One of my loyal readers sent me a note asking if I hug trees. They said “you write interesting stories about trees and the science of trees, but you don’t say much about your personal relationship wi...
substack.com
October 28, 2025 at 4:59 PM
One of my readers asked me whether, in addition to explaining the science of trees, I also hug them. Yes, I do.
Are you going to bring some poop-twig into your home this winter? Before you say “of course not,” answer this: will you bring some mistletoe into your home? Mistletoe means poop-twig! Find out more in our Sunday Tree story.
Sunday Tree: Mistletoe
Mistletoes are parasitic shrubs that grow in the branches of trees
open.substack.com
October 27, 2025 at 2:20 PM
Are you going to bring some poop-twig into your home this winter? Before you say “of course not,” answer this: will you bring some mistletoe into your home? Mistletoe means poop-twig! Find out more in our Sunday Tree story.
As the leaves disappear from our trees, we can suddenly notice an abundance of what look like green shrubs growing in many trees. These are mistletoes, plants with an important role in our Christmas celebrations, but a far more important ecological role in forests all over the world.
Tom Kimmerer (@tomkimmerer)
As the leaves disappear from our trees, we can suddenly notice an abundance of what look like green shrubs growing in many trees. They are very abundant in the Bluegrass where I live. These are mistle...
substack.com
October 26, 2025 at 10:06 PM
As the leaves disappear from our trees, we can suddenly notice an abundance of what look like green shrubs growing in many trees. These are mistletoes, plants with an important role in our Christmas celebrations, but a far more important ecological role in forests all over the world.
What do mistletoe and gibbons have in common? Both are featured in the coming week on Our Trees, mistletoe on Sunday, gibbons on Tuesday. Please join us then!
Tom Kimmerer (@tomkimmerer)
Our Trees will feature mistletoe on Sunday and gibbons on Tuesday.
Sunday Tree is about an important holiday plant, mistletoe. Mistletoe is common in the south, but we only notice it when the leaves ...
substack.com
October 25, 2025 at 5:29 PM
What do mistletoe and gibbons have in common? Both are featured in the coming week on Our Trees, mistletoe on Sunday, gibbons on Tuesday. Please join us then!
Our pleasure in food and drink can be greatly enhanced by memories of the places where we first encountered them. Drinking Boh Tea at my desk after a long day of writing evokes memories of my time in the Malaysian jungles, and I can hear hornbills and gibbons as I sip my tea. More at Our Trees.
Tom Kimmerer (@tomkimmerer)
On a long writing day, I’m enjoying my afternoon tea. Coffee and tea are often as significant for their memories and associations as for their flavor.
Boh Tea is grown in the Cameron Highlands of Mal...
substack.com
October 23, 2025 at 7:58 PM
Our pleasure in food and drink can be greatly enhanced by memories of the places where we first encountered them. Drinking Boh Tea at my desk after a long day of writing evokes memories of my time in the Malaysian jungles, and I can hear hornbills and gibbons as I sip my tea. More at Our Trees.
Autumn colors are very late in the Bluegrass because of many warm nights. This white oak should look like this now, but it is barely turning. It will not reach this stage until November. What are trees doing where you are?
Tom Kimmerer (@tomkimmerer)
We are about two weeks behind on our fall leaf transition in the Bluegrass because of unusually warm nights. The white oak, Quercus alba, in the photo will not reach this colorful stage until November...
substack.com
October 22, 2025 at 8:36 PM
Autumn colors are very late in the Bluegrass because of many warm nights. This white oak should look like this now, but it is barely turning. It will not reach this stage until November. What are trees doing where you are?
Here are notebooks I have kept in the last 2 years. I have 40+ years of notebooks in storage. Some are writing notebooks, and others are field notebooks. Keeping good notes is valuable in many fields. Notebooks are essential to writers and to field workers who collect data. More at Our Trees.
Tom Kimmerer (@tomkimmerer)
Many writers comment on the value of their notebooks, notably @Paul W. B. Marsden and @Kate Howlett recently. Some of us have a complex relationship with our notebooks. The picture shows the last two ...
substack.com
October 21, 2025 at 5:51 PM
Here are notebooks I have kept in the last 2 years. I have 40+ years of notebooks in storage. Some are writing notebooks, and others are field notebooks. Keeping good notes is valuable in many fields. Notebooks are essential to writers and to field workers who collect data. More at Our Trees.
Here is a splendid opportunity for a doctoral student in ecology in a very strong lab.
Please pass along, I’m recruiting PhD students to join our Macroecology Lab @uofa-eeb.bsky.social We study phys ecology, macroecology, biodiversity - spanning scaling, trait-based ecology, theory, comparative biology & ecoinformatics. Several avenues for funding. Please reach out if interested🧪🌐🌾
October 21, 2025 at 7:29 AM
Here is a splendid opportunity for a doctoral student in ecology in a very strong lab.
We are entering a season of celebration. This time of year, we will use an astonishing number of trees as decoration, food, drink, and fragrances. Join us at Our Trees as we begin our exploration of these trees.
Tom Kimmerer (@tomkimmerer)
As autumn fades, we enter a season of celebration. The traditions of this time of year call for use of many tree products. Some are familiar, like Christmas trees, coffee, chocolate. There is a great ...
substack.com
October 20, 2025 at 2:54 PM
We are entering a season of celebration. This time of year, we will use an astonishing number of trees as decoration, food, drink, and fragrances. Join us at Our Trees as we begin our exploration of these trees.
Our Sunday Tree story is about trees that may hide among other trees. Here are two very similar trees, and we usually overlook one of them.
Sunday Tree: Hidden Trees
Some trees are so similar to others that they escape our notice. Here is one.
ourtrees.substack.com
October 19, 2025 at 4:45 PM
Our Sunday Tree story is about trees that may hide among other trees. Here are two very similar trees, and we usually overlook one of them.
Autumn colors are very late in the woodland pastures of the Bluegrass. Most trees are still green, with a bit of flagging like this. This is a direct result of climate change causing warm autumn temperatures, especially at night. What are trees doing where you are? More at Our Trees.
Tom Kimmerer (@tomkimmerer)
The woodland pastures of the Bluegrass have barely begun showing color except for a bit of flagging like this. This is very late, and we can attribute it to high temperatures, especially night tempera...
substack.com
October 18, 2025 at 4:41 PM
Autumn colors are very late in the woodland pastures of the Bluegrass. Most trees are still green, with a bit of flagging like this. This is a direct result of climate change causing warm autumn temperatures, especially at night. What are trees doing where you are? More at Our Trees.
The elegant patterns in autumn leaves are due to expansion of compartments caused by insect, disease, and mechanical damage to leaves during the growing season. We don't notice these patterns until autumn, when compartments rapidly expand. Read more at Our Trees.
Tom Kimmerer (@tomkimmerer)
Trees do not heal wounds and have no mechanism for doing so. Instead, injuries to trees are walled off, a process called compartmentalization. For leaves, the many insults to leaves by insects, pathog...
substack.com
October 17, 2025 at 1:52 PM
The elegant patterns in autumn leaves are due to expansion of compartments caused by insect, disease, and mechanical damage to leaves during the growing season. We don't notice these patterns until autumn, when compartments rapidly expand. Read more at Our Trees.
Here is a brief story about why scientific (Latin) names are very important. Read it at Our Trees.
Tom Kimmerer (@tomkimmerer)
Three botanists sat down for a cup of tea together.
The first said “My sycamore is bearing lots of fruit this year. I made a big pudding and froze the rest.”
The second, puzzled, said “My sycamore i...
substack.com
October 16, 2025 at 2:06 PM
Here is a brief story about why scientific (Latin) names are very important. Read it at Our Trees.