Which Japanese Blueberry Plant Do You Want?
There is a fairly large number of Japanese blueberry species in existence although only a few of these are regularly seen on the market. Even then it pays to know what you are paying for. It seems that the terms tree, shrub, and bush are used a little freely, and that nice shrub you planned for a corner of the garden could grow into a 60 foot tree. Even the dwarf variety appears to come in several sizes, some not so dwarfish.
All varieties of the Japanese blueberry are very attractive, whether as a hedge or shrub or as an ornamental tree. The Japanese blueberry tree (Elaeocarpus decipiens) features foliage that is normally green but new foliage is bronze in color. In the autumn the leaves turn bright red. The red leaves will drop off but new leaves are always emerging, and the tree is an evergreen. The mature leaves are glossy and somewhat leathery in appearance. In the spring, late April to early May fragrant, creamy-white, bell shaped flowers cover the tree. If it is a tree you are after you'll need to allow for its spread which can reach up to 30 feet. It's safe to plant as a street tree or near a sidewalk as the fallen bluish-black berries are said not to stain concrete. The branching on the tree is quite tight, making it useful as a screen and also an attractive addition to a winter landscape. If planting as a screen, be aware that the Japanese Blueberry tree's growth rate is moderate and not rapid.
Planting As A Tree - If planting more than a single tree, they should be spaced a minimum of 40 feet apart, and planted in full sun. A tree will do best in soil with a pH in the range 6.6 to 7.8. The tree should be watered regularly until established, usually by the third year. After the first year you can allow the top 3 inches of soil to dry between waterings. The Japanese Blueberry tree that is only 2 or 3 years old appreciates a dose of general purpose fertilizer each spring before new growth starts.
Planting As A Shrub - If you elect to plan a shrub rather than a tree, look for a variety that matures to 11 feet tall or less. There are varieties that top out at 6 to 8 feet. A shrub under 6 feet will require frequent severe pruning, and if this is what you are looking for in terms of shrub height, another species of shrub may be a better choice. If you want a 7 foot shrub for example you’re going to have to trim the plant somewhat severely back to 6 feet and give it frequent lighter trims after that to maintain a 7 foot height. The Japanese blueberry shrub produces the same fragrant creamy-white flowers as does the tree and the same bronze to green to bright red leaves. Most shrub varieties have a spread of around 8 feet. Although the older foliage drops after turning red, the shrub, like the tree, is an evergreen. The shrub makes an excellent screen, and also is attractive as a backdrop for other plants in the garden. Its leaves have a peculiar twisted look, and the shrub can be sheared to fit in a formal garden, but when allowed to grow naturally has a definite tropical look.
The Japanese Blueberry should do well when planted in USDA zones 8 to 11. It is hardy to temperatures of 20 degrees F, and in some settings will handle temperatures as low as 10 degrees F. When planted as a hedge or a backdrop for the flower garden it's especially attractive with are hibiscus, plumbago, gardenias and larger varieties of lily as companion plants.
The Japanese Blueberry, whether a tree, shrub, or bush, is unfortunately not a plant that can be grown anywhere, but if you live in an area where it will do well, it would be an outstanding choice in a mid to large size garden.