Franklinia and Chitalpa Trees

Franklinia and Chitalpa Trees

Marianne C. Ophardt
Washington State University Extension
Area Horticulture Specialist

You’ve probably never heard of the Franklinia tree or the chitalpa tree.  They’re both uncommon trees that you’re not likely to find growing in this region. However, I think it would be interesting to try them and see how they well they would grow here. Don’t run to your local nursery and ask for these trees.  They’re not readily available and will probably only be something you can find in a specialty nursery catalog.

Let’s talk about the Franklinia tree.  It has a fascinating history.  It was first discovered in 1765 in Georgia by John Bartram of Philadelphia.  While Bartram’s occupation was that of gentleman farmer, he also studied philosophy, religion, medicine, and science.  It was his interest in plants and botany that gained him a place in history.  He made many botanical expeditions throughout the “New World” and earned himself the title of King’s Royal Botanist for North America from King George III of England.  

It was on one of his expeditions to Florida that John and his son William came across a beautiful blooming tree or shrub along Alatamaha River in Georgia.  Because they were anxious to reach their destination, they didn’t stop to collect samples. Ten years later William headed back to Georgia in hopes of finding and collecting specimens of this special plant.  He found the plant, retrieved specimens, and took them home to propagate them. William named the plant, Franklinia alatamaha, after his father's good friend Ben Franklin.

What makes the story interesting and the plant so rare, is that when a visit was made to the same location in 1803 the plant had disappeared.  No other native stands of this particular plant were ever found again.  It’s believed that all the specimens of the Franklinia tree in the United States and around the world come from those collected and propagated by William Bartram.

Apparently the Bartrams saved the Franklinia tree from virtual extinction.  This makes the tree very fascinating, but it’s the tree’s characteristics that make it truly special.  It’s a cousin to the camelia.   Large white flowers emerge from marble-size buds in late summer and continue coming along well into fall.  The flowers are three inches in diameter with an orange center and a delicate fragrance.  These remarkable flowers are sometimes still present when the tree starts to turn orange to red in the fall.

The Franklinia tree is a small deciduous tree or large shrub with an upright spreading form and an open base.  It usually only grows to about twelve feet in height, but there have been reports of taller trees. The tree is slow growing and difficult to transplant.  It requires a moist, acid, well-drained soil that high in organic matter.  While the Franklinia tree is winter hardy for our area (USDA Zone 5), it may not do well here because of our intense summer sun.  If tried in our region, it should be planted where it will be shaded from the sun during the heat of the day.  It would also be best to prepare a landscape bed for this special tree by adding compost or peat moss to the soil, along with mulching the tree with bark or compost and keeping the soil evenly moist. 

If you know of one growing in this region, let me know.  Last year to commemorate the 300th anniversary of John Bartram's birth, Martha Leigh Wolf of the historic Bartram's Garden in Philadelphia started a census of Franklinia owners wanted to “find out how far north and west the fabled plants grew, under what conditions they thrived, how long they could live, and how big they could get.”  They surveyed members of the American Association of Botanical Gardens & Arboreta and the Garden Writers Association of America. What they thought would be simple survey turned out to be much bigger with replies far beyond their expectations.  The little survey evoked hundreds of responses from all over the United States and as far away as New Zealand and Germany.  One gentleman even sent a picture of a Franklinia that he had taken in Korea in 1950.  Apparently, the Franklinia tree is beloved by its owners who know they are growing a very special and rare tree.

The chitalpa ( x Chitalpa tashkentensis) doesn’t have a similar rich history, but it is an interesting tree.  It’s not a native tree but a hybrid created in Uzbekistan by Nikolai Rusanov in 1964. It’s what is called a bi-generic cross... a cross between two genera of plants, the desert willow (Chilopsis linearis) and catalpa (Catalpa bignoides).   The chitalpa was first introduced into the United States by Robert Heff of the New York Botanic Gardens in 1977. 

The chitalpa is a fast growing deciduous tree or shrub with spreading‑arching limbs that form a dense broad-oval crown. The mature size is believed to be around 20 to 25 feet tall, but it hasn’t been around long enough to know for sure. This vigorous tree is drought resistant and able to withstand strong winds without breakage. 

The chitalpa’s parents are “messy” trees because of the litter they create with dropped flowers and many long seed pods.  However, the chitalpa is much better behaved. That’s because it’s sterile... not producing seed pods.  The sterile flowers also dry on the tree rather than dropping to the ground right after bloom. 

Perhaps the main drawback to growing the chitalpa in this region is that it may not be totally winter hardy.  It has withstood temperatures as low as nine degrees Fahrenheit, but it’s likely to die back to the ground after severely cold winters in our region. Its other characteristics that may be troublesome are is its tendency to sucker near the base and its susceptibility to mildew in cool weather. 

One of the best things about the chitalpa is its flowers.  The cultivar 'Pink Dawn’ produces numerous clusters of showy pale pink flowers in the summer.  Each cluster contains 15 to 40 one-inch long flowers with ruffled petals and lavender throats. The leaves are narrow and glossy.  Another cultivar ‘White Cloud’ is a bit less showy with white flowers.

It’s not easy to find sources of these two trees.  You can get both ‘Pink Dawn’ chitalpa from Forest Farm in Williams, Oregon at (541) 846-7269.