Juniper (Juniperus) Care Sheet
Tips and Tricks for Caring for Your Juniper Tree
The Juniper tree is a coniferous, evergreen shrub that makes a great option for bonsai because they are easy to prune and train. These are the most popular types of bonsai trees in the world.
Junipers enjoy sunny locations and can take full sun. Make sure to place in a location that receives at least four hours of sunlight daily. Make sure to protect from winter conditions and move indoors when it drops below 28° at night. Either place your tree in the ground (with the pot) and mulch up to the first branch, or place your tree in an unheated garage or shed. During this time, your tree does not need light; it is in its dormant state. Move your Juniper outside in the spring after night temperatures reach a minimum of 35°. You may keep your Juniper outside through the spring, summer, and fall in a spot where it will receive sufficient sun.
Junipers do best in zones 3 through 9.
Junipers prefer to be kept outside year-round in a bright location with lots of sun. You'll need to protect your tree from winter conditions (under 15°F), including protectng the root ball from frost. Some species change foliage colors during frost conditions to a purplish brown. This is normal and is the Juniper using its frost protection mechanism.
Junipers' roots do not like soil wetness. Do not overwater! To prevent overwatering, allow the plant to properly drain and the soil to become dry before watering again. If you are unable to water your tree, a humidity tray will help to retain moisture and humidity.
Junipers do best in a coniferous bonsai soil mix.
Use normal, organic fertilizer pellets every month or liquid fertilizer every weeks during growing season. For stronger foliar growth, you can apply some higher nitrogen levels in the spring. Do not fertilize immediately after repotting.
For Junipers under two years old, repotting must be done once every two years. Junipers over ten years old can be repotted every three to four years. Plant in a bonsai soil mix consisting of 1:1:1 Akadama, Lava, and Pumice, or one slightly more draining. Do not prune the roots too aggressively when repotting. Junipers grow well in containers.
Most propagate with cuttings. Seeds take up to five years to germinate.
Spring and fall is the best time for pruning. Maintenance pruning can be done year-round. Pinch out ends of new growth about once every six weeks while they are growing. Also, thin foliage pads with sharp scissors at the base. This will help keep the tree from becoming too dense. Junipers can handle aggressive pruning, but they cannot bud from bare tree parts. Leave some foliage on branches you want to keep alive. *The removal of all growing tips will weaken the tree and the cut will turn the needles brown. Keep only the strong, growing tips.
Junipers are often heavily wired when they are young. Use wire to train branches. Juniper branches can be bent aggressively but wrap branch with raffia tape or raffia for protection. Foliage pads should be wired and spread out after thinning to let in light and air. Dramatically twisted shapes are very popular, as well as cascade and semi-cascade styles.
If well taken care of, Junipers are very resistant to pests. Keep foliage from getting too dense, as this allows pests to settle in. Check for pests in the winter. Junipers can get infested with spider mites, juniper aphids, juniper webworms, and others. Junipers are subject to fungal diseases, such as cedar apple rust and juniper tip blight. Use the correct fungicide to treat your specific disease.
Coniferous Bonsai Soil Mix
KIKU™ Professionally Annealed Copper Bonsai Wire