The spectacular ornamental specimen trees known as Japanese flowering cherries comprise various cultivars of the Prunus serrulata species. Most sold commercially are 'Kansan' ('Kwanzan'), or 'Sekiyama' cultivars; the pure species is rarely planted. There are other flowering cherry trees available, but these P. serrulata cultivars are favorite choices for home landscapes since they are smaller, tidy trees that don't create any fruit and have a very attractive, upright, vase-shaped growth habit. (Though the cultivars don't grow fruit, the straight species Prunus serrulata does.) These trees erupt in gorgeous white to pinkish-red blossoms during the spring months.
Cherry trees are normally planted in the fall, well before frost to give them a chance to establish roots. These are fast-growing (1 to 2 feet per year), but rather short-lived trees. The leaves, stems, and seeds of cherry trees are toxic to pets and humans.
|Common Name||Japanese flowering cherry, Kanzan cherry, Oriental cherry|
|Botanical Name||Prunus serrulata cultivars|
|Plant Type||Deciduous tree|
|Mature Size||15–25 ft. tall , 13–26 ft. wide|
|Soil Type||Loamy, well-drained|
|Soil pH||Neutral (6.7 to 7.1)|
|Flower Color||Pinkish red blooms|
|Hardiness Zones||5–8 (USDA)|
|Native Areas||China, Korea, Japan|
|Toxicity||Seeds, leaves, stems toxic to humans and animals|
Japanese Flowering Cherry Care
Grow Japanese cherry trees in full sun and in well-drained loamy soil with plenty of humus. Planting is best done in the early fall, generally from container-grown nursery specimens. Keep the soil evenly moist, because this is not a drought-tolerant tree. While some cultivars grow to be moderately large, it's possible to grow Japanese flowering cherry trees in containers or even as bonsai plants if you choose a compact cultivar.
These are temperamental plants that are susceptible to a large number of pest and disease issues. Careful care can keep the plant healthy enough to resist many problems, but don't be surprised if your tree succumbs after 15 to 20 years. It's a rare year where you won't be treating the tree for some insect or fungal disease, but the spectacular spring bloom is worth it for most gardeners.
Japanese cherry trees grow best in full sun, which means it needs at least six hours of direct, unfiltered sunlight each day to produce optimal blossoming. However, the tree can tolerate partial shade.
This type of cherry tree will tolerate a variety of soil types, but it prefers moist, fertile, well-drained loam with a relatively neutral pH. Ideal soil will make this plant less susceptible to the many fungal diseases that can plague the species.
Japanese flowering cherry prefers plenty of moisture—at least 1 inch per week. Add a layer of mulch to the top of the soil to keep it moist and insulated, particularly during the winter months. Once well-established, Japanese flowering cherry will tolerate short droughts.
Japanese cherry trees have been known to survive winter temperatures down to minus 10 degrees Fahrenheit, which means that they can be borderline hardy in the northern part of zone 5. Zones 5b to 8a are ideal climates, as more southern gardens may not provide the 45-degree winter dormancy these trees need.
Prolonged periods of cool, wet, and humid summer weather can be a problem for these trees, since it fosters a number of fungi that can create serious disease for cherry trees.
Feed Japanese cherry trees once a year in the spring with a fertilizer that's specifically developed to be used with cherry trees.
To fertilize organically, back-fill with some compost when planting and top-dress periodically thereafter, watering the nutrients into the soil.
Types of Japanese Flowering Cherries
The genetic heritage of the Japanese flowering cherry is a complicated one, as P. serrulata likely is the result of crossbreeding of many wild species, along with the Oshima cherry (Prunus speciosa). Most commercially available Japanese cherries are grafted trees, in which ornamental cultivar branches are fused to a wild cherry rootstock.
There are several popular award-winning cultivars of P. serrulata, including:
- 'Kanzan' is a very popular variety that grows up to 30 feet high and 25 feet wide, with deep pink double blossoms. This is the most popular of all Japanese flowering cherries.
- 'Kiku-shidare', also known as Cheal's weeping cherry, has arching, cascading branches. It grows to 15 feet tall and wide and has rich pink double blossoms.
- 'Fugenzo' has beautiful white flowers that gradually turn pink. It grows to 30 feet tall and wide.
- 'Shirotae' has large pure white flowers, up to 2 inches across. Growing to a maximum of 20 feet with slightly arching branches, it is ideal for small landscapes.
- 'Asano' has puffy, full flowers resembling those of chrysanthemums. It grows to 20 feet.
Generally speaking, very little pruning is necessary for Prunus serrulata cultivars, other than removing damaged branches. In fact, the more you prune, the more likely you are to allow fungal diseases to take hold.
If you need to prune, do so after the tree flowers. Make sure to sterilize your cutting tools after each cut. Sometimes, the limbs can grow too quickly and heavy for the base. Prune away the heavy branches as needed.
Propagating Japanese Cherry Trees
Most ornamental cherry trees are created by grafting branches from a selected cultivar onto the hardier rootstock of a wild cherry. Therefore, propagating them yourself is an iffy prospect, since the plants resulting when you root stem cuttings will not have the hardy rootstock. The shape, size, and overall vigorousness can be quite different than your parent plant. But if you wish to experiment with propagating through stem cuttings, here's how to do it:
- Take a semi-hardwood cutting from the tree during the summer months, choosing a branch that has two to four leaf nodes and leaves.
- Cut off a 4- to 8-inch section at a horizontal angle and remove the leaves from the bottom two-thirds of the branch. Dip the cutting into rooting hormone.
- Push the cut end into a mixture of half perlite and half sphagnum peat moss. Pat down the soil around it.
- Place a loosely secured plastic bag over the container, and move the pot to a sunny location. Mist the cutting twice a day to keep the soil moist.
- After two to three months, gently tug on the cutting to see if it's rooted. If there's resistance, let the cutting grow until the roots have filled the pot.
- When ready, transfer the plant to a gallon-sized container filled with potting soil and move it outside to let it acclimate to temperatures for a week before transplanting the tree to a location with full sun.
How to Grow Japanese Flowering Cherry From Seed
Most Japanese flowering cherry tree cultivars are sterile and produce no fruit. Thus, propagating by seed is not an option.
Potting and Repotting
Most ornamental cherry trees are too large for container growing, but if you choose a smaller cultivar of P. serrulata and are willing to prune regularly, it is possible. Such plants can make excellent patio specimens.
Use ordinary commercial potting soil in a large, deep, well-draining container. Repotting will be difficult, so start with the largest container possible. Some experts recommend replacing a good portion of the potting soil every two to three years. Feed the plant with a good controlled-release fertilizer each spring. A potted tree will need to be watered regularly—several times a week in hot weather.
Over much of their hardiness range, Japanese flowering cherries require no winter protection. However, gardeners in the northern part of the range (zone 5) may want to mulch the ground around young trees with a thick layer of dry straw or leaves to protect the roots from cold over the winter months.
Clean up of fallen leaves and other debris can prevent fungal diseases and insect larvae from overwintering to reappear in the spring.
Common Pests and Plant Diseases
Unfortunately, these beautiful trees are susceptible to many pests and diseases. In fact, their susceptibility to a number of pests earns them the dreaded "short-lived trees" label. Gardeners who want to enjoy the spectacular beauty of Japanese flowering cherry should be prepared to spend considerable time treating pests and diseases.
Peachtree borers are a notable pest problem for these (and other) cherry trees. For borer control, most experts simply advise keeping the tree vigorous (and therefore less susceptible to borer attack) by providing adequate irrigation and fertilizer. You can use spray pesticides formulated for peachtree borer to treat current infestations.
Other small pests that trouble this tree are scale insects, spider mites, and aphids. You can generally blast these pests off the leaves with a strong spray from your garden hose. Tent caterpillars will eat the leaves, so remove their silky nests as soon as you spot them before much damage can be done. Japanese beetles can also feed on the tree's foliage. Control severe infestations of Japanese beetles with spray insecticides
A number of serious diseases can affect Japanese cherry, including leaf spots, dieback, leaf curl, powdery mildew, root rot, and fireblight. Consult your local Extension service for diagnosis and solution recommendations.
How to Get Japanese Cherry to Bloom
Japanese flowering cherry trees will normally bloom quite robustly if they are healthy and in a favorable location (plenty of sunlight, well-draining soil).
One problem that can affect a tree's bloom is brown rot, a fungus that causes brownish spores to appear on the buds and blossoms. The flowers often shrivel and fall off before they can even open. Affected leaves and blossoms should be raked up and destroyed. Fungicides may offer some help for brown rot, but you may lose your tree's blossoms until next year.
A tree that gets nipped by hard frost just as the buds are appearing may also lose its blossoms for that year. This isn't a serious problem, as the tree will probably bloom just fine the next year. But branches that die back should be removed.
Common Problems With Japanese Cherry
Japanese flowering cherry trees are prone to quite a number of common symptoms, a few of which are listed here. Keeping your tree healthy is the best preventive measure, but the Japanese flowering cherry is a tree that sometimes requires a professional arborist to diagnose and treat problems.
A significant problem is bark-splitting, whereby large cracks emerge in the trunk. Such a crack can allow disease organisms to enter and subsequently cause decay. As a solution, trace with a knife just outside the split in the trunk and then remove the bark from inside the traced area. This will prevent the crack from expanding and, if the tree is otherwise healthy, the area should callous over, preventing the incursion of disease organisms.
Gummy Residue Around Trunk
This is often an indication that the tree is fighting peach tree borers. You may also see wounds and cankers on the trunk of the tree when borers are attacking. Permethrin or other powerful insecticides will likely be necessary to control these pests, but take care not to spray during the bloom period, as this will kill pollinating bees.
Ragged Holes in Leaves
This is usually caused when Japanese beetles are feeding on the foliage. One effective method of control is to use pyrethrin-based insecticides. Horticultural soaps can also be effective, though application on a full-sized tree can be problematic.
How long does a Japanese cherry tree live?
P. serrulata can be fairly short-lived—between 15 and 25 years—mostly because it's very susceptible to pests and disease. There are cases of well-cared-for trees lasting 50 years or more, but this is rare.
What other flowering cherries can I consider?
Not all flowering cherry trees fall into the official category of Japanese flowering cherry. A few other popular choices:
- 'Accolade' is a cultivar of P. subhirtella, which is itself a complicated hybrid. Growing to 25 feet with an arching habit, this variety has beautiful shell-pink flowers.
- Yoshino cherry (Prunus x yedoensis) is a slightly larger tree (up to 40 feet) that produces small berries, bitter in taste but popular with birds. It has good fall color and is useful as a small shade tree. Its flowers are white, tinged with pink.
- 'The Bride' is a cultivar of Prunus incisa. It has pure white flowers with pink/red centers. Growing to just 6 to 7 feet, it is a good choice for small patio gardens or for growing in containers.
Are the cherries edible on this tree?
Most cultivars of Japanese flowering cherry are sterile and produce no fruit. If you want to grow a cherry for its fruit, choose a cultivar of the sweet cherry group (Prunus subgroup avium) or tart/sour cherry group (Prunus subgroup cerasus).
How is Japanese flowering cherry best used in the landscape?
Japanese cherry trees can function in the landscape as fast-growing shade trees for small spaces, such as patios, or as specimen trees for spring display. Smaller cultivars can make good potted trees.