Katsura “Cercidiphyllum japonicum” is a native tree to Japan and China. It is hardy in U.S. Department of Agriculture zones 4 through 8. This deciduous tree grows 40 to 60 feet tall with a spread of 20 to 50 feet. Depending on the variety chosen, some trees grow in a pyramidal shape, while others are wide spreading.
The Katsura can grow a foot or more every year. During the summer, the leaves emerge in a purple color, but as they mature, they turn a bluish green. The leaves are heart shaped or ovate rounded, resembling redbud (Cercis). When fall comes, this tree will not disappoint you with its beautiful yellow to apricot autumn colors. Another wonderful thing about this tree is in the fall the leaves give off a spicy, brown sugar scent.
You can propagate your own Katsura tree quite easily. The Katsura tree flowers in the spring. While the tree is in bloom, you need to find the female tree. A female tree will have red flowers in the spring. The male tree has green flowers. After the flowers fade, they will turn into small green pods. These will ripen to a coppery tan. Pick the seed pods before they break open and release their winged seed. If you don’t have your own Katsura tree, or know of anyone who does, you can buy the seed from some garden supply stores or online.
Gather the Seeds and Sow Them
In the spring or fall, gather some 4-inch pots. Cover the drainage holes with a coffee filter, pieces of shard, or small rocks. If you don’t have pots, you can also use a seeding tray. Fill the pots or seeding tray with seed-starting soil. Leave ¼ inch of space between the soil and the pot’s rim. You will need one pot for each seed you want to plant.
Moisten the soil thoroughly. Set the tray or pots on a drainage rack to allow the excess water to drain away.
Space each seed in the seeding tray at least 3 inches apart. If you are planting in the pots, place one seed in the center of the each pot. Barely cover the seed with grit, coarse sand or finely sieved potting soil. The seeds need some light in order to germinate, so don’t cover them heavily.
Fill a sprayer bottle with water. Mist the top soil or sand to moisten.
Find a Bright Location
Cover the pots, or seeding tray with a clear sheet of plastic. Find a bright location to place the pots or tray, but keep them out of direct sunlight or it will get too hot for the seeds to germinate. You will also want to germinate the seeds in a room that stays around 70 degrees Fahrenheit.
Check the soil daily for moisture. If the soil is dry, mist the top of the soil to keep it moist, but not soggy. After two weeks, start watching for the seeds to germinate. When the seeds germinate, remove the clear plastic sheet.
Continue to grow the plants in the bright location. Water when the soil feels dry. The soil needs to be kept evenly moist. When the seedlings get their second set of true leaves, transplant them into 6-inch pots filled with all-purpose potting soil. Grow the Katsura tree indoors in the 6-inch pots for a period of one year. After that, transplant them outdoors in a sunny location.