Phellodendron amurense - Amur Corktree
Family - Rutaceae
Size - To probably 30 feet in the south, although it can go to 45 feet. Spread is comparable to height. Medium growth rate, 1 1/2 feet per year. Possibly 2 feet with adequate moisture. The trees in these photos were grown from seed collected in Cave Hill Cemetery, Louisville, Ky. They respond very well to being container grown and can reach a decent landscape size in 2 growing seasons.
Foliage - Opposite, pinnately compound, dark glossy green, pungent when crushed. Fall color is yellows, somewhat negligible.
Flower/Fruit/Seed - Trees are separate sexes (dioecious). Clustered seeds, 1/3" in diameter; green turning to black in the Fall; persisting through winter. Seed are pungent when bruised, and quite oily.
Bark - On old trees develops a ridged and furrowed corky bark; gray-brown. The bark is very attractive.
Pests and Diseases - Free of insect problems. Related to the garden herb Rue which is known to be a insect deterrent. It and Phellodendron are both in the Rutaceae family. The pungent smell of the foliage when crushed is a dead giveaway on anything in this family.
Landscape Use - Shade tree for large areas, parks, campuses, golf courses, etc. Can be used in the home landscape.
Performance - 7 Although trees have fared well, they haven't thrived. They would probably do better in a loamy soil with adequate moisture. These trees are in somewhat horrid soil conditions on slightly sloping ground with poor absorptive ability. All in all, it seems to be a moderately adaptable and tolerant tree for this area considering it isn't supposed to be very tolerant of hot climates. Trees in Louisville that were grown from the same seed lot have tripled the size of these in Alabama in the same timeframe. This could partly be due to seasonal temperature differences, but there are so many different influences such as moisture and soil fertility which can make a difference from one site to the next. Chances are good that depending on the site one could achieve great differences in response and growth rate in the Louisville area also. Can be propagated from seed very easily. They will sprout about as fast as one can sow them with a slight stratification of about 1 month.