Gymnocladus dioicus
Origin: Swarthmore, Pennsylvania
Improvement status: Cultivated wild material
Seeds per packet: ~8
BOTANICAL SAMPLE - NOT GERMINATION TESTED
Life cycle: Perennial
Kentucky Coffee Tree is one of the most beautiful native trees in North America. Loaded with beautiful cascades of white flowers, followed by large pods, and with its broad, spreading, compound leaves, it looks like it would be at home in the tropics. But it is a deciduous hardwood that loses its leaves every fall. The tree gets its name from its large shiny seeds, which can be used to produce a coffee substitute after roasting (though they must be roasted: the raw seeds will make you sick). The wood is highly sought after by carpenters for the beautiful red-orange color of its heartwood (which contrasts well with the yellow-white sapwood).
We collected these seeds from the campus of Swarthmore College outside Philadelphia (with the help of our grower and friend Dylan Bruce), which has many spectacular trees on its arboretum of a campus. A groundskeeper told me that anything that falls to the ground there is fair game, so when Dylan and I noticed a huge Kentucky Coffee Tree with pods and seeds littering the ground beneath it, we decided to spend some time gathering. Days after we had collected a few pounds of seeds we learned that this tree happens to be the state champion (tallest) tree in all of Pennsylvania!
GROWING NOTES: This tree evolved in the presence of large herbivores that would eat the pods and disperse the seeds. Without them, the seeds are a bit tricky to germinate, but two methods are common: 1) Bring water to a boil, then turn it off and wait 30 seconds before dropping the seeds in and letting them soak for 24 hours; 2) File the seedcoat to allow the seeds to imbibe water, then soak for 24 hours before planting. These plants are native from a few scattered populations in New York and Pennsylvania across the Midwest and upper south to Tennessee, Oklahoma, and southern Minnesota. Trees reliably hardy Zones 4 to 8. Species is dioecious, so for eventual seed production you will need both female and male plants.
NOTE: Photos shown are public-domain images of the species, not the PA state champion tree (we will have to go back for a photo later this year). The photo of the seeds shows the actual seeds in this lot.
