Jennifer Schultz Nelson
Extension Educator, Horticulture
Last year my husband was watching a gardening show on TV, and saw a tree that he immediately wanted for our yard-- Franklinia alatamaha, the Ben Franklin Tree. It has become a bit of an obsession for my husband this spring, trying to find a source for a tree bigger than a seedling.
We asked about the tree at a local nursery recently, and their staff agreed it was a great tree, but they didn't carry it. Maybe next year.
What's the big attraction to this tree? Several features of this tree give it multi-season interest, which heightens the attraction.
Franklinia is a small multi-stemmed tree, its maximum height is only 15 to 20 feet tall, making it an attractive accent for the home landscape. The very unique feature of this tree is the flowering. This time of year in Illinois, we are surrounded by spring-blooming trees and shrubs. Franklinia is a very late bloomer, and is one of the last trees to leaf out in the spring. It doesn't begin to flower until early August, and continues flowering right up to the first hard frost. Very few plants begin their flowering this time of year, when most everything else in the garden is looking pretty tired.
The white flowers are three inches in diameter with bright orange-yellow stamens in the center. Flowers are borne on the ends of branches from buds which resemble green pearls. The flowers are also fragrant.
But the benefits of this tree don't stop with the flowers. After the flowers, the tree has beautiful red and orange fall color, sometimes along with a few late flowers. Winter interest is provided by grey-brown exfoliating bark and persistent seed pods.
There is some debate as to the hardiness of Franklinia. Some sources list it at hardy to Zone 6, some to Zone 5. We are technically Zone 5b, almost Zone 6. I think growing Franklinia is worth a try. Protecting the tree from damaging winter winds will increase your chances of success in overwintering Franklinia.
That said, Franklinia is particular about where it is planted. It prefers, even requires well drained soil, as it is prone to root rots. Franklinia also needs acidic soil of pH 5.0-6.0 with high levels of organic matter to perform well. Heavy clay alkaline soil common in this area would need to be amended in order to have any chance of success with Franklinia.
Franklinia is also considered to be a slow growing tree. This is probably why the only trees my husband and I have seen for sale have been fairly small.
Another attractive feature of the Franklinia, at least for me, is that is comes with a great story. This tree is a piece of living history.
The Franklinia was discovered by father and son explorers John and William Bartram in 1765 along the Altamaha River in Georgia. The tree was not in flower the first time they saw it, so it didn't attract a lot of attention. On a return trip in the 1770's, they witnessed the tree in flower, and called it "of the first order for beauty and fragrance". They collected seed so they could propagate the tree in their Philadelphia garden and named the tree Franklinia to honor John Bartram's friend Ben Franklin.
After 1803, the trees were never seen again in the wild. The tree is alive today because of the Bartrams' collecting trips. What happened to all the Franklinias in the wild? Some experts believe there was a flood event along the Altamaha River that wiped out the Franklinia trees growing along its banks.
Growing the Franklinia is literally growing a piece of our country's history. All Franklinias grown are descendents of the original trees propagated by John and William Bartram. The oldest documented specimen of Franklinia is 104 years old and lives at the Arnold Arboretum in Boston.
Will we grow Franklinia in our yard? Eventually. Since site preparation is critical for success, we will need to test our soil and amend it to be more suitable for Franklinia. Soil test instructions are available from University of Illinois Extension. Call my office at (217) 877-6042 for more information.