Long lived and celebrated wherever it grows, the iconic and majestic ginkgo tree (Ginkgo biloba) is our focus this fall.  It is an easily recognized tree — the leaves resemble fishtails or fans and can be found in parks, street plantings and in public arboretums and gardens. Through the Ginkgo Watch 2020 program, we invite you to participate in monitoring the color changes of our historic and state champion, the Painter ginkgo (planted between 1840 and 1860).  

fish tail leaves


This is a phenology study. 

What is phenology?  Phenology is the science of appearance. The word phenology comes from the Greek words phaino (to show or appear) and logos (to study). Scientists who study phenology are interested in the timing of specific biological events such as flowering time and leaf color change in relation to changes in season and climate. Seasonal and climatic changes are some of the non-living components of the environment that impact the living. Seasonal changes can include variations in day length, temperature, and rain or snowfall.  For an extended definition of phenology, go to Project Bud Burst.

This is what we will be doing from October 15 to November 15. We are looking at when the ginkgo leaves begin to turn, what color stage they will be in and when the drop will occur.  Ginkgos have a tendency to drop all of their leaves at once making it easy for us to study.  Join us and become a citizen scientist.  More information about the ginkgo after “How?” section.


Throughout Ginkgo Watch 2020, we will be monitoring the Painter Ginkgo which is located by Lachford Hall. Here’s how you can help —

  1. Bookmark this page so you can have easy access to the reporting portals.
  2. Visit the Painter Ginkgo on a regular basis once a week. Pick out the color that best matches the entire tree by submitting your observations here.
  3. Photograph the Painter Ginkgo and submit the photo to camera icon. The address to use for the Painter Ginkgo picture is: 515 Painter Road, Media Pa, 19063.  
  4. If you know of a ginkgo near you and you want to document it, you can submit the data for that tree by using the same camera icon. Know many trees?  Submit as many as you want, just be sure you return often to update the information. 
  5. The data from #3 and #4 will populate a map which can be viewed here:


Want the map on your handheld? https://tinyurl.com/ginkgoleaves2020

Why the Ginkgo?

Ginkgos are often called ‘living fossils’ because they date back 150 million years in the fossil record. This long history means that Ginkgos can yield important data about the way the earth has changed over that time period. We can track data collected from fossils and living trees around the world to learn more about climate change and shifting weather patterns.


Or watch this video produced by the same people at the Smithsonian.

What makes the Painter Ginkgo so special? This ginkgo is an important part of the story of how this settlement (now Tyler Arboretum) developed from a working farm to a public arboretum. The Painter brothers planted this tree sometime between 1840 and 1860 — one among a thousand other trees they planted. At the time, ginkgos were a relatively new discovery from plant explorations to China. The tree was first encountered by European plant hunters in 1690. It was brought to Europe and cultivation began around 1730 to 1760. It was finally brought to North America, actually through Philadelphia in 1784.

Our tree was purchased and planted close to Lachford Hall. Since then it has witnessed many changes. Over nearly two centuries, the property transitioned from growing crops and grazing cattle to becoming a cherished community centric arboretum.

ginko porch

According to our staff and volunteers, we estimate final leaf drop to be during the first or second week of November. Of course this is a guess as the leaf color change and leaf drop will be determined by many factors such as moisture, wind, day length, temperature and much more. Over the past few decades we’ve seen the earth’s climate warm and the local weather change and those changes can be stressful for our plants. There have been years when a sudden cold snap in late October causes the ginkgo leaves to drop before they ever change to brilliant gold. No matter what happens this year, Ginkgo Watch 2020 will yield important scientific data that we can use for years to come.

Take a moment to wonder what this beautiful tree might witness going forward, and help us collect data that will enable us to better understand our living world.