Tom Kimmerer, PhD

This is how we make beautiful cities.

Joshua trees are uncommon, with a limited range, and threatened by climate change. Read what scientists are doing to stabilize the species.

This old bur oak, Quercus macrocarpa, on the University of Kentucky campus is one of my favorites for its fine form. It predates the existence of the university by several hundred years. Unfortunately, that building behind the tree was filling with people and the parking lot was jammed.

Autumn is arriving and trees are preparing for the cold. This is not a simple response of trees to changing weather, but a complex series of physiologic events in trees that begins in early spring. Have a look at Our Trees.

Wendell is no longer physically with us, but his writings and his influence on our society will continue. The threats to our planet are severe, but, inspired by Wendell, we will push back and care for our Earth.

At Our Trees, we are discussing pawpaw, which has become very popular in recent years. Are you a pawpaw fan? Read the story and take the quiz.

It’s the anniversary of my major career change that connected me to trees for life. Read about it at Our Trees.

Here is an exciting postdoc opportunity.

This is a wonderful opportunity!

Climate, Lightning, and Trees Lightning is a major cause of death of large trees and the climate crisis is increasing lightning frequency. Read more about what lightning does to trees at Our Trees.

In a seminar when I was a grad student, the lecturer said "When digging for potatoes, it is not so important to dig like hell as it is to dig where the potatoes are." That has been the guiding principle of my work in science ever since. It is written on the first page of each of my notebooks.

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.

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.

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.

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.

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.

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.

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!

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.

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.

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.

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.

On a warm, breezy morning before the rains come, we like to hang the kids out to dry.

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.

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.

Here is some late evening Bluesky for you, along with a blue ash tree and a moon. Enjoy!

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.

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

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.

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.

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.

A true story of the cobra under my desk.

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.

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.

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.

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.

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?

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.