thousand canker disease

Death by a Thousand Cankers

We have posted a new article at Planet Experts, Death by a Thousand Cankers, about the tragedy of a new disease of black walnut.  Although not yet in Kentucky, is it present in surrounding states.  The disease is new and began in the western United States, where black walnuts have been introduced as ornamentals.  Since […]

Keep Growing Until We Have to Quit – The Yellow-Poplar Strategy

Trees are generally very conservative in their growth habits. They often go to extremes to avoid rare events such as an early frost or severe drought. This is especially true of shoot growth. Although we think of trees as growing all summer, most trees only grow in height for a few weeks. Flowering dogwood sets […]

Mower damage, old (O) and new (N)

Street tree abuse – Part II

Street tree abuse is our term for management of street trees that results in their death, or in severe damage that shortens their lives. We have previously shown examples of this throughout the Lexington area. Now, we show an egregious example of street tree abuse while it is happening.The scene is the Legacy Trail, a […]

Bur oak with lightning scar and lost crown

Lightning and Trees

Lightning and Trees seem to go together. Many fires in the Western US are started by lightning strikes on trees. Here in the Bluegrass and Nashville Basin, we find fire scars on a very large number of trees. Lightning rarely kills our trees, but it is an important factor in their lives. Lightning-struck trees lose […]

Street Tree

Street tree abuse – Part 1

Street tree abuse is all too common in many cities. Here, a tree was planted to high, leaving its roots exposed on the surface. This would not be a serious problem – it is better to plant too high than too low – if it weren’t for subsequent damage by mowers. Every exposed root of […]


What, if anything, is a species? Part 1

Two trees grow next to each other in a woods in the Bluegrass region of Central Kentucky.  Can you identify them?   Are these two different species or one?  Post your answers in the comments below or on Facebook, then tune in for a discussion of these pictures tomorrow.  Over the next couple of weeks, […]

Canopy shyness

Canopy shyness

Canopy shyness is the tendency of trees to reduce competition between adjacent trees by maintaining a space between branches. It is easy to see in tropical forest canopies. which tend to be flatter than temperate canopies. Looking up into a tropical forest canopy (in this case a lowland forest in Peninsular Malaysia), you can see […]

Ginkgo tree killed by stem damage

Killing ginkgo trees

Killing ginkgo trees is not easy. The most ancient tree species on earth, it seems to have outlived most of its pests and pathogens.  The main cause of death for urban ginkgo trees is damage from mowers and string trimmers, and soil compaction. A ginkgo in Bell Place Park, in Lexington, KY, is on the […]

Second flush of growth

Tree are Popping

We think of summer as the “growing season” and we are used to our garden plants growing all summer. For most trees, though, growth takes place mostly in the early spring. Most trees in temperate regions produce a single flush of growth – the bud opens, and leaves that were formed the previous year expand […]

water drops on a leaf

Water droplets on leaves

Look at the two leaves below. The oak leaf has flat, rather dull drops. The redbud leaf has round, shiny drops.  If you look around at leaves after a rain, you will see some leaves with round, shiny raindrops like the redbud, while other leaves will have flat drops like the oak, or will shed […]

Winter Sex: The Puzzling Case of Witchhazel

This is part of our ongoing series on tree sex.  Witchhazel is one of the most beautiful shrubs or small trees in forests throughout the temperate zone.  It is easy to overlook in the summer, mixed in with lots of other shrubs and trees along creek banks and moist lower slopes of forests.It is in […]