One of the most popular bonsai trees is the Juniper bonsai. These coniferous shrubs have over 50 species in its family. The looks of these trees are pretty diverse, with foliage ranging from lighter greens to dark blue greens, and needle- or scale-like foliage. Usually junipers will start off with needle-like foliage and grow scale-like foliage later in its life. Its original needle-like foliage can grow once again if the tree is under some sort of stress, like over watering, heavy pruning or wiring. After a few years this foliage can be removed and its scale-like foliage will grow again.
Their cones are berry-like and very small – ranging from 2cm to 3mm- and are either round or oval shaped. After a year or two, they will ripen, but it is very common for birds to spread the cones through their droppings. Junipers are also commonly used for creating deadwood.
Identifying Your Juniper
As previously mentioned, Junipers are divided into two categories: needle-like and scale-like foliage.
There are many popular Junipers with needle-like foliage. One example of this is the Green Mound Juniper Bonsai. This Juniper from Japan has short, compact, blue-green foliage. The Japanese Needle Juniper has stinging needles that are dark green and have a white line down its length. Native to North America, North Africa, Europe, and Asia is the Common Juniper. Unlike the Japanese Needle, their needles are small and delicate.
Common Junipers with scale-like foliage are the Japanese Shimpaku and the Chinese Juniper. These Junipers are particularly diverse in color, ranging anywhere from yellow-green, green-blue, and green-gray. Emerald-green, delicate foliage makes the Itoigawa Shimpaku very popular.
Many of the Chinese Junipers look so similar, that it is very hard to distinguish one species from another. Savin Junipers, which originated in North Africa, Europe, and parts of Asia, have either fine or coarse foliage, and range in shades of green depending on where it’s from. Keep in mind all Savin’s are poisonous! California Juniper’s have blue-gray foliage, and are native to -you guessed it- California. Sierra Junipers are insidiousness to western United States. These trees are dark green or gray in color and are pretty dense.
Caring For Your Juniper Bonsai
Junipers are pretty picky bonsai trees. They are very particular about the amount of water they recieve and need lots of light. These trees are also sensitive to frost and cold weather. With proper care, your Juniper shouldn’t face too many problems with pests and diseases, but it is possible for problems to arise anyway.
Positioning A Juniper Bonsai
Junipers are outdoor bonsai trees and need lots of light with no shade. While some trees are able to survive indoors or outdoors, Junipers are not. Protect these trees from temperatures below 14 degrees Fahrenheit. If your tree turns purplish brown in the winter, this is normal. This is to protect itself from frost. In the spring, its normal color will return.
Watering A Juniper Bonsai
These trees are pretty particular about their water intake. These trees do not like soil wetness, so avoid watering too much. Junipers respond to leaf misting very well as this will boost its air humidity.
Fertilizing A Juniper Bonsai
During the growth season, fertilize once a month with organic fertilizer, or once a week with liquid fertilizer. To encourage growth, use a fertilizer with high Nitrogen levels.
Wiring A Juniper Bonsai
Junipers take to wiring very well. Because of this, dramatic shapes and twists are often associated with the Juniper bonsai. When acquiring a bonsai, you may notice that many Junipers are wired heavily at the start of their lives. While their branches can be bent rather strongly, you must be very careful when wiring deadwood. If the deadwood is old and large, deadwood can be split off and bent into the more flexible parts of the tree. Wire foliage pads when necessary in order to let air and light in and prevent the foliage’s inner parts from dying. In addition to this, dense pads can increase the risk of pest infestation.
Pruning A Juniper Bonsai
Throughout the growth season, if development of foliage pads is desired, you can pinch or cut off the long shoots that grow out of the silhouette. Trimming these trees like a hedge by removing the growing tips will turn their needles brown and will weaken the tree. Thin out dense foliage pads at the base with sharp scissors. Once a tree part has no buds left on it, buds will not grow again. So, if you want a branch to stay alive, keep some foliage on it.
Juniper Bonsai Diseases and Pests
So long as these trees are properly cared for, you shouldn’t have many problems with diseases and pests. If foliage gets too dense, pests will want to live in it. Junipers are also susceptible to pests in the winter, so you will need to provide them plenty of light and check them for pests regularly. Common pests your tree may become infected with are juniper aphids, juniper needle miners, juniper scale, spider mites, and webworms. While insecticide or miticide sprays or sticks can help, finding the reason your tree became vulnerable to pests in the first place. Fungal rust diseases are another common problem in certain Junipers. The degree at which they are resistant varies from species to species. Yellow-green junipers are not as resistant to rust fungus as green-blue junipers. Some are even resistant to this disease, and others, like Japanese junipers are rarely infested. This disease is, unfortunately, permanent. Brown galls emerge from the swellings that develop on the infected tree. During rainy spring seasons, these galls will form big orange tendrils that are filled with spors that will infect pear trees or other hosts like crabapples. Removing infected parts of the tree does not guarantee that the diseases will not come back. It is best to burn or throw away your tree in the gargabe.