Tom Kimmerer, PhD
@tomkimmerer.bsky.social
I am a tree scientist and botanist writing about relationships between trees and humans including climate change. A Fulbright Scholar, Author of Venerable Trees and more books in progress. Read about trees here: https://ourtrees.substack.com.
This amazing basswood, Tilia americana, came up in a discussion, and I thought you might enjoy it. Despite its setting, this is not a planted tree and greatly predates this cemetery. I hope you enjoy it.
Tom Kimmerer (@tomkimmerer)
Yesterday’s basswood leaf prompted a comment from Alder Burns regarding this amazing species, American basswood, Tilia americana. Basswood is a species of linden. Here is a picture of the tree that ga...
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Looking closely at a tree can be quite rewarding. The white flower of this flowering dogwood is not really a flower, but a complex inflorescence containing dozens of tiny green flowers. The tree does this not to trick us, but to attract pollinators to its tiny flowers. Have a look.
Tom Kimmerer (@tomkimmerer)
Trees can be tricky at times. Look, for example, at the beautiful white flower of flowering dogwood, Cornus florida. In common parlance, it is a flower. But in the reproductive life of this tree, the ...
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Here is a brief story about the cover of my first book Venerable Trees and why the blue ash tree on the cover is significant.
Tom Kimmerer (@tomkimmerer)
This is the cover of my first book, Venerable Trees. The book designer did a wonderful job, selecting this picture from several dozen that I provided. This is a large blue ash, Fraxinus quadrangulata...
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I visited my local bison herd this morning. It is good to remind ourselves that bison are not strictly western animals. They were the dominant herbivore of the Bluegrass and created our woodland pasture ecosystem. More at Our Trees.
Tom Kimmerer (@tomkimmerer)
I took advantage of today’s fine weather to visit my local bison. You may think of bison as western animals, but they were first seen by European settlers in what is now downtown Washington DC and onc...
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One of the most beautiful small trees in our flora is staghorn sumac. It grows in dense clusters in woodland edges and bears beautiful and useful red fruit from late summer through winter.
Sumac
Staghorn sumac is a beautiful small tree that forms dense thickets in woodland edges. The fruit makes delicious drinks and a popular spice.
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Midwest Native Plant Conference · Beavercreek, OH · July 31–Aug 2. @tomkimmerer.bsky.social keynoting on venerable trees. Conference sold out — but public is invited to the plant sale Sat Aug 1, 10am–5:30pm. midwestnativeplants.org -C
Midwest Native Plant Conference – Native Plant Event in Ohio
July 31–Aug 2, 2026 · Bergamo Center, Beavercreek, OH. Keynotes on native trees + shrubs. Public Native Plant & Artisan Sale Sat Aug 1, 10am–5:30pm.
midwestnativeplants.org
On my morning walks, I often see trees, especially black walnuts, covered in mistletoe, Phoradendron leucarpum. Mistletoe is abundant in the Bluegrass on many trees, especially black walnut.
Tom Kimmerer (@tomkimmerer)
On my morning wanderings, I often see black walnuts covered in mistletoe, Phoradendron leucarpum. It is common on walnuts and other hardwoods, especially in the Bluegrass. Mistletoe leaves are green a...
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Professor Joyce Onyenedum is a skilled botanist, a professor at NYU, and a great storyteller. If you are looking for more well-told stories about plants, you want to visit her YouTube channel. Check her out!
Professor Joyce Onyenedum
Welcome! This channel is dedicated to sharing my love of plants with anyone who will listen. My name is Dr. Joyce G. Onyenedum, and I am a Botany Professor at New York University in New York City. ...
youtube.com
Our wet summer is allowing many trees wo produce late flushes of growth, often with pale leaves. This is quite unusual in chinkapin oak, a slow-growing tree. Here is a huge chinkapin oak in a woodland pasture in the Bluegrass, and a second flush of growth with pale leaves.
Tom Kimmerer (@tomkimmerer)
In my part of the world, The Bluegrass, this is an extraordinary summer to be a tree. I don’t recall a summer with such frequent rain, and the trees take advantage of wet summers like this produce flu...
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This is the oldest known painting of a tree. It is on a rock wall in Serra di Capivara National Park in Brazil. The painting is at least 20,000 years old. Learn more at Our Trees.
Tom Kimmerer (@tomkimmerer)
Given the long and essential relationship between trees and hominins (humans and their ancestors), and the wide use of trees in art, here is a surprise: cave paintings and rock art is ancient but gene...
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Encouraging news came this week of a reinvigorated program to restore blight-resistant American chestnut. If successful, this would be the biggest news for our eastern forests since the chestnuts were wiped out before 1950. This is reason for optimism.
Tom Kimmerer (@tomkimmerer)
The Return of American Chestnut? American chestnuts have been a part of my life since I was a kid. We would buy fresh roasted chestnuts from street vendors in Baltimore. I didn’t know it but by the t...
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The Trump regime wants to destroy American science. One big step to maintain our strong science just happened, as Dr. Neil Shubin became President of the US National Academy of Sciences. Shubin is an important paleontologist and an equally important interpreter of science for the lay public.
Tom Kimmerer (@tomkimmerer)
The Trump regime is working hard to destroy American science, corrupt our science institutions, steal our natural resources, and drag medicine back by a century or more. The good news is that American...
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On a warm, breezy morning before the rains come, we like to hang the kids out to dry.
Tom Kimmerer (@tomkimmerer)
It will rain for much of this week, but for now the warm breeze is allowing us to hang the kids out to dry. Photo by Tom Kimmerer
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The Indonesian volcano Gunung Merapi is seen just after midnight on July 4 2026, in celebration of the natural world, instead of our political world.
Tom Kimmerer (@tomkimmerer)
Last night, at the stroke of midnight on the 4th of July, my favorite volcano,* Gunung Merapi in Java, Indonesia, decided to celebrate with a huge lava flow, shown live all over the world. I think o...
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Here is a magnificent kingnut, Carya laciniosa. Kingnut was the original English name, but it was later called shellbark hickory. The original name is far more appropriate. This is an exceptionally large and elegant specimen in a woodland pasture, with a blue ash behind it.
Tom Kimmerer (@tomkimmerer)
Let’s have a look at another uncommon tree. Kingnut, Carya laciniosa, is an uncommon tree in the midwest, especially on limestone. It is a spectacular tree that is large in all its aspects. The tree i...
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Here is some late evening Bluesky for you, along with a blue ash tree and a moon. Enjoy!
Tom Kimmerer (@tomkimmerer)
A blue ash tree at night. Blue ash, Fraxinus quadrangulata, is common on limestone uplands throughout the midwest, especially in the Bluegrass. The tree is named for the blue dye that can be extracted...
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If you were making beer in Kentucky in 1779, you did not have access to the ingredients we use now. Instead, settlers used honeylocust and persimmon fruit. I have made beer according to the recipe in the linked story and it was quite good. Check out the story at Our Trees.
Tom Kimmerer (@tomkimmerer)
Making beer in 1779 In the early days of colonial settlement of Kentucky, two precious beverages were coffee and beer. Coffee was an important trade item brought by traders coming across the mountain...
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For your enjoyment, here is an ancient bur oak, Quercus macrocarpa, under a full moon on the University of Kentucky campus. Photo by Tom Kimmerer
Tom Kimmerer (@tomkimmerer)
An ancient bur oak, Quercus macrocarpa, under a full moon on the University of Kentucky campus.
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Late season flushes of growth in trees, leading to pale yellow-green foliage, used to be an uncommon late summer phenomenon. Now, it is happening every year, a result of climate change. Read about it at Our Trees.
Climate Change and the Summer Flush in Trees
Trees sometimes produce a second flush of growth, which is often pale compared with the first flush. This used to be a rare phenomenon but now occurs every year, probably due to climate change.
open.substack.com
The summer solstice is not just a calendar entry. It is a signal to all the trees in temperate zones in the north to begin preparation to survive the winter cold. Yes, today, the growing season ends for most trees. Have a look at the trees you walk by. Most of them have probably already set buds.
Tom Kimmerer (@tomkimmerer)
Today is the summer solstice. Perhaps it is just a date on your calendar, but it is a signal occasion to temperate trees: the growing season has ended. From now until next spring, most trees are doing...
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Here is the current global warming stripe for the US. We are making progress toward renewable energy, but the fossil fuel oligarchy and its minions in the trump regime are doing everything they can to slow the adoption of renewables. They will fail, but every day of delay makes the crisis worse.
This is Gunung Merapi (Fire Mountain) near Yogyakarta, Indonesia from a live camera tonight. The Special Region of Yogyakarta is one of the most fascinating, beautiful places on Earth. I taught at Universitas Gadjah Madah and had the pleasure of climbing Gunung Merapi. I hope it settles down soon.
The fruit flies in my kitchen always remind me of the great biologist Tom Morgan, who grew up down the street from where I live. Read about him here.
Tom Kimmerer (@tomkimmerer)
This morning, my kitchen was filled with fruit flies, Drosophila melanogaster. This is not surprising as I keep a lot of tropical fruit on hand. Fruit flies always remind me of science. As an underg...
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Sassafras is an important tree both for its stunning beauty and for its long history in cuisine and medicine. Have a look at Our Trees.
Tom Kimmerer (@tomkimmerer)
Sassafras, Sassafras albidum, is a tree that is deeply embedded in our culture not only for its beauty but for its long-term medicinal and culinary uses. Is there any tree more spectacular than sassa...
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Baldcypress is a glorious tree in southeastern wetlands, the longest-lived eastern tree and one of the largest. It is increasingly common in urban landscapes. Do you know this tree? Take a look at Our Trees.
Tom Kimmerer (@tomkimmerer)
We have been discussing trees that have close relationships with humans. Here is one with an increasingly close association with our landscapes. Baldcypress, Taxodium distichum, is a huge, unusual tre...
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I have seen many stories on Substack and elswhere claiming that almonds are a good choice for our health. This is true, but there are better choices for our planet, and the best choice is pecans.
Pecans or Almonds? The choice is clear
Both are nutritious, but pecans are a better choice for our planet
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Here is another tree with a history tied to us. Catalpa is a gorgeous tree, but its native range is tiny. Due to a 19th century craze in planting this tree for railroad ties, it is now everywhere. It made lousy railroad ties, but it sure is nice to have in our landscapes. Read more at Our Trees.
Tom Kimmerer (@tomkimmerer)
Catalpa is another tree that has benefited from its relationships with humans. Originally native to very small areas in the southern US, several enthusiasts began mailing seeds to anyone who wanted t...
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Osage-orange, or hedge-apple, is a tree very familiar to those of us in the Bluegrass, where it was widely planted for natural fencing and hedges. Do you find this tree where you live?
Tom Kimmerer (@tomkimmerer)
Here is another tree whose abundance and distribution is due to its close relationship with us. Osage-orange, Maclura pomifera, is certainly one such tree. Once found in a small area of Texas and adja...
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Black locust is a very successful tree in our human-dominated world. It is spectacular in flower and produces exceptionally fine honey. Learn more about this amazing tree at Our Trees.
Tom Kimmerer (@tomkimmerer)
Black locust, Robinia pseudoacacia, is one of the most successful species in our modern landscape. Increased disturbance - forest clearing, farming, surface mining - favors this amazing tree. It seeds...
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