The Tree Pen Project

Volunteer Opportunities

Venerable Trees, Inc, is looking for volunteers to help establish and monitor tree pens in the Bluegrass. We are looking for a few people to volunteer their time on Saturday mornings in the spring and fall to help with:

  • Putting up fences, either barbed wire on metal posts, or wood plank fences;
  • Inventorying the woody and herbaceous plants inside the pens at the time the fences are put in place;
  • Continued monitoring and inventory of plants that come up in the pens over several years. This will likely take the form of late spring and early fall inventories.

Visit the Volunteer Page to register for our tree pen events. 

Our woodland pastures are disappearing. Age, development, mower damage, and other factors are causing the loss of ancient trees throughout the Bluegrass and Nashville Basin.  As we lose the oldest trees, they are not being replaced by an adequate population of young trees. Woodland pastures were created by the long-interval intermittent grazing of large herbivores, especially bison.  Today, with continuous grazing and mowing, there are few places for the seeds of these trees to germinate, survive, and grow to maturity.

The problem is not that these trees don't produce enough viable seed or fruit - they are quite prolific. In places where mowing and grazing has stopped, the venerable tree species often reproduce in abundance. However, without grazing, these places quickly turn to dense forests, favoring other, shorter-lived species. 

One solution would be to re-introduce long-interval intermittent grazing, allowing cattle into a pasture every few years. This has been done on a small scale at several farms and appears to work. However, it is prohibitively expensive for most farmers, tying up land that they need for grazing.

As an alternative, we are looking at tree pens as a potential way of creating the proper grazing intervals. A tree pen is simply a fenced area, ranging from a quarter acre to an acre, from which livestock are excluded for a period of time.  Many farms have tree pens, either to protect existing large trees or to allow planting of groups of young trees. Most often, given current practices, the trees planted in these pens are not the most desired venerable tree species. 

Venerable Trees, Inc, has received a generous grant from the Josephine Ardery Foundation to allow us to place experimental tree pens on several farms.  We are cooperating with several farms who will provide fencing material.  We will provide volunteer labor and long-term vegetation sampling. There are a number of questions and challenges that we will address:

  • Will natural regeneration from seeds from nearby trees be adequate?
  • Will we need to supplement natural regeneration by planting young trees?
  • Will weeds, especially bush honeysuckle, prevent natural regeneration?
  • How long will it take for trees in the pens to become large enough for the trees to survive if the fence is removed?
  • What other vegetation - grasses, cane, shrubs, forbs - might help the trees to grow, and keep out nonnative species such as honeysuckle? 

Over the next few years, we will address these and other questions related to tree pens and the reproduction of our venerable tree species.  We installed the first tree pen in Jessamine County, and are working to establish up to 20 tree pens throughout the Bluegrass.

Volunteers and Dr. Kimmerer installing fence posts for the tree pen.

Volunteers placing corner posts in the tree pen.

Mary Rigg-Holthaus and Dr. Kimmerer removing invasive species from a tree pen.

Removing invasive species and taking inventories of species in the tree pen is an ongoing task.

Tree pen

Tree pen with extensive bur oak reproduction