The Oldest Tree Species on Earth

The Ginkgo or Maidenhair tree is one of the most beloved and intriguing trees. Beloved for its’ unique fan shaped leaves that turn bright yellow in the fall, intriguing for its position in biological history and cultural importance. In Mandarin Chinese, Ginkgo is scientifically named yinxing, or “silver fruit” tree, although it has had many names over the centuries, my favorite being yazhangshu, or “duck foot” tree. The word “Gingko” that we use in botanical nomenclature is derived from a misspelling of the Japanese transliteration (ginkyo- “silver apricot”) of the Chinese names for the tree, which include yinxing (silver fruit) and baiguo (white nut), both in reference to the medicinally important seeds.

Ancient leaf forms. Heather Coste.

By now, it’s common knowledge that the Gingko is the oldest extant species on earth today, having fossil records dating back 190 million years. Ginkgoes are gymnosperms, which means they produce “naked seeds”, or seeds not enclosed by fruit. The rancid scent loathed by many is produced by butyric acid in a pulpy layer that envelopes the seed, which gives it the false appearance of a true fruit. For a long time, Ginkgoes were grouped with conifers, although they are not true conifers as they don’t produce cones. Recently, they have been classified into their own division, Ginkgophyta, of which they are the only representative of the class, order, family, genus, and species. 

Typically found in warm temperate deciduous and evergreen mixed forests, the Ginkgo could be found communing with numerous other woody species such as Japanese Cedar, Golden Larch, and China Fir, all of which we have located in the arboretum. The populations of Ginkgo have grown and shrunk over the millions of years of its existence; once naturally found all over the globe, it appears that Ginkgo went extinct in North America about 7-10 million years ago and in Europe about 2-2.5 million years ago. Ginkgo populations persisted in Eastern Asia and are now considered native only to China, but it’s popularity and usefulness among humans have spread the species around the world once again. 

Ginkgo fruit and turning foliage. Heather Coste.

Ginkgo cultivars all derive from the species Ginkgo biloba. Genetic testing indicates that all Ginkgoes outside of China were introduced from China, so the genetic diversity of the species is limited. Unlike oaks, which easily hybridize between the hundreds of species in existence and easily give rise to hundreds more species and cultivars, any Gingko cultivar is solely a product of a chance mutation on Ginkgo biloba, most likely from a witch’s broom- a tangled mess of shoots at the end of a branch that can be caused by fungal infection, terminal bud death, mite infestation, or genetic mutation. Many of the dwarf cultivars in the trade come from witch’s brooms caused by genetic mutation, which are the only ones stable enough to propagate vegetatively. Nevertheless, horticulturalists and plant breeders have been able to produce many unique forms of Ginkgo in form, habit, and leaf morphology. 

Ginkgo biloba ‘Procumbens’ Heather Coste. (1974-OP588)

Ginkgo biloba ‘Mariken’, Heather Coste. (2012-0001)

Unlike some of the relict species discussed in the newsletter (like our Cathaya agrophylla, aka “The Great Panda of the Tree World”), the Ginkgo reproduces easily on its own and propagates easily from cuttings, budding, and grafts. Gingko cultivars are produced in the trade by grafting the mutated scion wood onto species rootstock, a process Ginkgo takes to so well you can expect an extremely high success rate, if you can get the scion wood. The slow growing nature of these sports and mutations limits the amount of scion wood in the trade, creating high demand for all the newest and trendiest cultivars. 

At the arboretum we have a small collection of Gingkoes comprised of 6 larger specimens planted within the last 70 years (mere infants compared to the 1,400-year-old tree in China), and 8 dwarf specimens that can be found in the Conifer Garden, some in unique growing conditions. As you get to know our Ginkgo collection, you will understand how this beautiful tree survived millions of years of change through adaptability and resilience. 

Ginkgo growing out of a rock. Heather Coste. (2018-0080)

A Community Effort

Throughout the year we set both short and long term goals for the Arboretum landscape. This not only keeps us organized but also allows us to prepare for upcoming projects. Understanding the budget, scope, and needs of a project gives us the opportunity to gather the proper resources. This time last year our Japanese Zelkova (Zelkova serrata) in the Royce Rhododendron Garden was showing significant stress (1990-RCD14). After some diagnostics we determined the roots were being compacted by a nearby path which caused a secondary issue of water runoff. We only have two Zelkovas at the Arboretum. This tree is a particularly beautiful specimen that provides significant dappled shade for our rhododendron collection. It was planted in 1990 and is a key element to the garden. A general rule of thumb at the Arboretum is trees come first. So instead of letting the tree suffer and potentially be removed, we decided to move the path instead.

Chase Callahan, the head gardener for Royce, brainstormed different ways to reroute the path away from the Zelkova root zone. Starting in June, the path was moved and two garden beds were combined to eliminate traffic in the area. We took the project a step further and air spaded the tree roots to greatly improve the compaction. We could not have done this work without the help of Jolly Green Tree and Shrub Care and LaMay's Tree Service. They generously donated their equipment and time to help revitalize the Zelkova. Our staff spread compost and soil to the area to prep for the next step which was planting. 

The new garden bed under the Zelkova was now ready to be planted. In the winter, we created a plant palette of groundcovers that would suppress weeds and add seasonal interest to the garden. This consisted of hellebores, ferns, epimedium and asters. We ordered a total of 885 plants! To help us install everything, we graciously worked with volunteers from the Lufthansa group. Our relationship started back in 2021 with their ‘help alliance Americas’ program. They adopted the garden and we are fortunate enough to receive much needed help with biannual volunteer events. The Lufthansa group had over twenty volunteers plant 885 plants and shrubs in just three hours! The area has transformed significantly and the Zelkova tree is shining more than ever. 

With the help of our local arborists and community groups, the Arboretum is able to accomplish great projects and goals. The ability to plan these projects and have the resources to accomplish them is truly appreciated. As a public entity, we rely on volunteers and donated services to be able to not only maintain our landscape but enhance it for our community. A big thank you to the Lufthasa group, Jolly Green Tree and Shrub Care and LaMay's Tree Service for assisting in protecting the Zelkova tree with a new garden bed and path. If you are interested in setting up a volunteer event or donating your time/service, please email Carolann Gaites (carolann.gaites@parks.ny.gov) and Michele DeRubeis (michele.derubeis@parks.ny.gov).

A beautiful view while scouting for Beech Leaf Disease!

Angela Noh, 2024 Horticulture Intern

Spotlight Grounds Tour

Wednesday, July 10, 2024 - 10:30AM to 11:30AM

Saturday, July 13, 2024 - 10:30AM to 11:30AM

Docents will spotlight specific, seasonally appropriate areas of the Arboretum in a one-hour grounds tour. Available only on the first Wednesday and first Saturday of each month. $5.00 per person. Call (631) 581-1002 for availability, required registration, and more details.

Forest Bathing Walk

Join certified forest therapy guide, Linda Lombardo of Wild Heart Nature Connection, on a walk to reconnect with the natural world around us.

Saturday, July 13, 2024 - 10:30AM to 12:30PM

Fee: $40 per person.

Please wear comfortable, sturdy shoes and warm clothing for walking outdoors. Register here!

Watercolor Workshops with Teresa Cromwell

Have fun with watercolors and go home with a finished picture ready to frame!

Fee: $50 per Student

All materials are provided by the instructor. Feel free to bring your own paints and brushes to class. Registration, additional dates, and more information can be found on our website.