Every year Japanese cherry trees beautify gardens and parks around the world. If you live outside the warmest and coldest regions of the USA, you can have your own “cherry blossom time” by planting a Japanese cherry tree in your own yard or garden.
History of the Japanese Cherry Tree
Japanese cherry trees, or sakura, are a group of about 100 species of flowering cherry trees that originated in Japan. Unlike the spindly cherry trees found growing wild in Europe and North America, native Japanese cherries have always been cultivated close to places where people live.
Japanese cherry trees grow to considerable size, making them suitable for viewing their masses of pink or white blossoms in spring. These cherry trees are raised for their blossoms, not for their fruit.
For over 1200 years, Japanese gardeners have selected the most beautiful cherry trees every spring. They grafted especially beautiful branches onto existing trees, or took pollen to cross with other trees to create new strains. By the time of the shoguns (1603 to 1867), cherry blossom time had become a national holiday celebrated by drinking sake under a beautiful, blooming Japanese cherry tree.
Japanese cherry trees are well known outside of Japan thanks to the efforts of an eccentric Englishman named Collingwood Ingram, a British ornithologist and plant collector. Ingram and his wife fell in love with the sakura on their honeymoon in Japan in 1907.
Ingram buried a cutting from a Japanese cherry tree in a potato and took it home with him via the Siberian Express. Over the next few years, Collingwood sent Japanese cherry trees to over 100 countries.
By 1926, Ingram had become such a renowned expert on Japanese cherries that he was invited to speak to the Cherry Society in Tokyo. At the conference, he was told that the white Japanese cherry had gone extinct in Japan. Ingram, however, had a white Japanese cherry in his own garden in England. He cloned it and saved the white cherry tree in Japan.
The famous flowering cherry trees in Washington, D.C. were a gift to the United States from the Japanese government in 1912. Every spring, hundreds of thousands of tourists from all over the United States come out to see these amazing Japanese cherry trees, now over 100 years old.
Japanese Cherry Tree Characteristics
Japanese cherry tree characteristics have evolved over centuries of breeding efforts. The Japanese cherries of 1,000 years ago had a shape similar to that of a weeping willow. Their branches drooped down almost to the ground, forming a cascade of blossoms every spring.
In the Kamikura period, beginning about the year 1200, Japanese cherries were crossed with exceptionally long-lived cherry trees found deep in the woods. Some individual trees used to provide genetics for the evolving Japanese cherry are currently 1,500 to 2,000 years old.
In the 1500s and 1600s, Japanese cherries were bred to be “double flowered.” This gave them as many as 50 petals on each flower.
In the early 1900s, there was an amazing variety of Japanese cherry trees in Japan. As the population grew and Japan modernized, however, all varieties except the Yoshino were chopped down in Japan, leaving it to Ingram to preserve the trees that provide genes for modern Japanese cherries.
Japanese cherry trees today come in several well-known varieties:
- Yoshino cherry trees are covered with white blossoms from top to bottom for about a week in the spring. This is the variety of the tree that Japanese people associate with Japanese cherries, and it is the variety you will see in Washington, D.C.
- Kawazu-zakura cherry trees are covered with dark pink blossoms at the end of winter, before the weather warms up. It gets its odd biological clock from its ancestors on tropical Okinawa.
- Yae-zakura cherry trees have more than five petals per blossom. Some species have blossoms with more petals than are easy to count.
- In 2007, Japanese scientist Riken used ionizing radiation to produce a Japanese cherry tree with greenish-yellow blossoms on the tree that turn white when they fall.
There are Japanese cherry trees that grow to 50 feet tall, some that do well in containers, and others that are grown as bonsai.
Some species of Japanese cherries have pendulous blossoms, hanging down like streamers, others that grow into a rounded shape, and still others with irregular, jagged branches.
The variations seem limitless when it comes to Japanese cherry trees.
There are varieties of Japanese cherry trees that are adapted to USDA Hardiness Zones 4 through 9. Some varieties grafted onto sour cherry rootstock are only viable in Zones 4 through 6, while container-grown trees may even bloom in Zone 9.
All Japanese cherry trees can tolerate hot, humid summers (like those in Japan) once they are established, but the need for chilling hours is variable. Your nursery will know which varieties work best for your location.
Size and Spacing
Some of the pendulous varieties of Japanese cherry trees, that bear flowers on long, weeping willow-like stems that droop down to the ground, only need to be planted 12 to 15 feet apart. If you plan to train the tree to grow on an arbor or canopy, you should have all the woodwork done and painted at the time you plant the tree.
Full-sized Japanese cherry trees need to be planted 20 to 40 feet (6 to 12 meters) apart, depending on how you plan to prune and train them. Japanese cherry trees grafted to dwarfing rootstock (your nursery can tell you which), only need to be planted 5 to 10 apart(1-1/2 to 3 meters) apart.
You can easily grow a Japanese cherry tree in a 40-gallon (150-liter) container filled with a mixture of sphagnum moss, perlite, vermiculite, and compost. You will need to prune it so it does not grow more than 6 feet (2 meters) tall.
Since you grow a Japanese cherry tree for its blooms, not for its fruit, you do not have to worry about pollination.
Japanese cherry trees can be very easy or very difficult to care for, depending on how much you want to restrain their growth.
Japanese cherry trees, like other cherry trees, prefer to grow in full sunlight. They will do well with dappled afternoon shade. Don’t plant them against a wall where they do not get morning sun. It’s important for the leaves to dry off in the morning to prevent bacterial diseases and mildew.
Japanese cherry trees need constantly moist but never boggy soil. They don’t grow well in heavy clay, and they usually don’t thrive next to streams.
In the summer, give them a thorough soaking when the soil around them is dry 2 inches (5 cm) down, if you don’t expect rain. Don’t give trees so much water that it stands around the tree.
The principle behind pruning Japanese cherry trees is the same as for pruning other fruit trees. Excess branches need to be removed for sunlight and air circulation to reach lower and inner limbs. Dead wood that can’t support foliage should be removed so the tree has more energy for flowering.
The best time of year to prune a Japanese cherry tree is in late winter. You don’t want to prune a tree so early in the year that new growth is stimulated while the weather is still cold.
For Japanese cherry trees with pink blossoms, prune about two weeks before your expected last frost. For white-blossom cherry trees, prune about the time of the last frost for the season. For any Japanese cherry tree, you should wait until the flower buds are just beginning to show spring color but aren’t open yet.
You’re not worried about fruit production, but you still should avoid summer pruning. Summer is the time of year that your Japanese cherry tree adds height and width.
When you prune a Japanese cherry tree, you’ll need a hand pruner, long-handled lopping shears, and a pruning saw. Sterilize your cutting tools with bleach before and after each tree.
Remove any suckers growing from the rootstock or from the base of the tree. Then remove any weak branches, cutting flush with the stem or trunk where they are attached.
Make cuts at an angle so moisture falls off of the cut. Water pooling on a cut can grow bacteria.
If your goal is to keep your tree small, you should top it in the first year or two of growth to control its shape. If your tree is at least 30 inches (about 75 cm) tall, then cut the leader at a 45 degree angle about 24 inches (60 cm) above the ground. This is the only time you should ever top your cherry tree.
In subsequent years, trim the branches that grow out from the tree to give in the shape and size you want.
Common Uses for Japanese Cherry Blossoms
Japanese cherry fruit are small, bitter, and mostly seed. The seed, like the seeds of all stone fruits, contains toxic amounts of a chemical called amygdalin, which your body turns into cyanide. Don’t eat the fruit.
Japanese cherry blossoms, however, make an interesting tea. You can steep fresh Japanese cherry blossoms in hot water or dry them for use later in the year. You can also find cherry blossom tea in larger supermarkets.
e leaves contain the blood thinner coumadin, the same chemical used to make the drug Warfarin. Don’t eat them or use them in tea.
Health Benefits of Japanese Cherry Trees
There aren’t any health benefits of eating Japanese cherry fruit. You shouldn’t eat them, ever.
However, there are health benefits to the practice of shinrin-yoku, or “bathing in the forest.” Taking in the beauty of Japanese cherry blossoms has been shown to lower stress hormone levels and blood pressure.
Where Can I Buy a Japanese Cherry Tree?
Visit Nature Hills Nursery for more information!