There may be no tree prettier than a well-grown katsura… and chances are you’ve never heard of it. It’s been over 90 years since it was first introduced to Ann Arbor, and there are some choice mature specimens in our area. Given that it’s the tallest deciduous tree in all of Japan, you’d expect it to be more widely recognized.
Katsura (Cercidiphyllum japonicum) is a first choice among tree connoisseurs, or most anyone who has been privileged to see a proper mature specimen, such as the gigantic one at Michigan State University’s Beal Botanical Garden. The tree sports luscious cascading branches with refined heart-shaped leaves that are elegantly arranged both in pairs and singly along the stems. The leaves emerge a bronzy color in spring, remain clean and green all summer, then turn a myriad shades of apricot, red and yellow in the fall. As a bonus the fallen leaves emit a sweet fruity cotton-candy fragrance that permeates the area. I know by the smell when one is nearby.
Katsura trees are not common in Ann Arbor. There are a handful of large specimens on private property, but none accessible to the general public, as far as this writer is aware. Nichols Arboretum received seed as early as 1917, but none of the early attempts to get the young plants established were successful. However the Arboretum houses two nice specimens of uncertain origin that are located just a very short walk down the path from the Geddes Rd entrance. Katsura is dioecious (with male and female flowers on separate plants), and one can easily note the difference between the male and female plants. The inconspicuous flowers appear before the leaves in the spring, with the female flowers developing into small bean-like follicles that look like tiny bananas.
On campus there is a planting of 11 specimens in the courtyard of the School of Business, all but one lining the parking garage to the south. The younger solitary specimen is grown with light from all sides and shows off the trees typical attractive form. The very first katsuras I ever saw were the ones growing on the east side of Residential College (East Quad) in the recessed courtyard. I was immediately impressed by them but stymied in early efforts figure out what they were. Later I took a summer job near Philadephia where I saw a spectacular specimen that drew crowds to the Morris Arboretum.
The leaf of katsura looks very much like that of the familiar redbud, so much so that it was given the latin name Cercidiphyllum, which translates as ‘redbud leaf’. There are only two species of katsura, one from Japan and the other from China. The genus is placed in a family all its own, Cercidphyllaceae, so these are odd-ball plants, currently considered distant relatives of witchhazels.
One reason you don’t see more katsuras is that they won’t thrive without proper soil and moisture. Of the six specimens planted in 1962 along the driveway entrance to Matthaei Botanical Garden, only one survives, and it’s a runt considering its age. The concrete ocean around Briarwood Mall was originally landscaped partly with katursas, but not one survives. However I planted one from a nursery into the sandhill I call my garden in Chelsea, and it didn’t skip a beat. After four years I decided to cut it down before it completely dominated the space. And there is one multi-trunk specimen west of Ann Arbor on private property whose trunk measures a full 3′ in diameter.
A good guideline would be to plant it in a spot with deep loose-textured soil, and don’t let it dry out until its root have become well established. You might consider trying out the readily-available cultivar ‘Pendula’, which famed plantsman Michael Dirr described as looking like “blue-green water cascading over rocks.”