Bonsai Juniper Trees - Easy to Grow and Great Starter Trees
The Juniper and in particular Juniper Procumbens is the go-to Bonsai tree - a definite must have particularly for the beginner. Juniper Bonsai trees, with their naturally low and spreading habit are natural for many different bonsai styles.
Growing Juniper Bonsai begins with the understanding that this is an outdoor bonsai. some Junipers - natably procumbens nana will survive indoors, but take them outside when you can.
Junipers like lots of sun and they also like to dry out a little between waterings, but don't let the soil dry out completely. Spray the foliage during the growing season. Avoid fertilizing Juniper in the hottest part of the growing season.
Juniper Procumbens is naturally hardy in zones 6-8. The foliage has a fine texture and to develop the foliage for your bonsai Juniper you should pinch out the tender new shoots ( all through the growing season) using your fingers. Needles cut by scissors will turn brown.
Wiring is best done in autumn or early winter. The newly wired branches will become used to the new shape while the Juniper tree is dormant over the winter. Watch wire carefully - particularly during the growing season for signs that its cutting into the bark. If that happens - remove the wire.
Ideally, repot in the spring - young trees as often as annually, but older trees only every 3-4 years. You can prune the roots when you repot, but don't take more than one third of the roots - some peeple would say one quarter.
Regardless of the hardiness of your Juniper Bonsai tree in its full form, you must protect the tree - specifically the roots during the winter. Depending on where you live, how cold it's going to get and what kind of snow cover you receive you might be able to leave it outside in a sheltered spot - maybe with a covering of leaves. In colder areas - bury the root zone and add some protective covering or even bring it into an unheated garage. Even during the winter if you can, be sure to water - lightly and infrequently, but still don't let it dry out completely.
Juniper Procumbens "Nana" is a dwarf cultivar and very popular as a Bonsai Juniper as is Juniperus Procumbens "Green Mound" (also sometimes referred to as a chinese juniper)
Two other very frequently found Juniper Bonsai trees are the Chinese Juniper - J. chinensis which is a little hardier - tolerating up to zone 4 (but NOT as an unprotected bonsai juniper tree) and The Shimpaku Juniper also known as Sargent's Juniper (juniperus chinensis "sargentii"). When young, the Shimpaku has needle like folliage but as the tree matures the foliage takes on the characteristic scale- like form. Shimpaku Junipers are native to Japan, and north of Japan on the Sahalin peninsula and Kurile Islands.
Below is a pre-bonsai Shimpaku Juniper.
and to the right is a mature Shimpaku - about 35 years old and you can see the difference in the foliage.
During the growing season - but avoiding the hottest part of the summer and any time the tree is stressed you can feed a half strength balance fertilizer (20-20-20) about every other week. If you are planning to wire, or re-wire your juniper, it's best done at the start of the winter. While the tree is dormant you don't need to worry about the wire getting too tight and cutting into the bark.
When you're training your Juniper bonsai never trim more than one third of the roots at any one time and be prepared to pinch out tender young shoots all through the growing season to develop the foliage.