Recently purchase a Juniper bonsai tree? You’ve come to the right place to learn everything you need to know about caring for your little one. Popular bonsai trees such as these require proper care and nurturing, so we’re going to lay out all the information you need to help it grow and thrive the best it can. We’ll cover a brief background on the species of Junipers, where to put them for optimal growth, watering and misting methods, fertilization frequency, pruning care, repotting, and potential pests and diseases to look out for. All you bonsai enthusiasts get comfortable, get your notebook ready, and let’s get started!
About The Juniper
Juniper Bonsai (Juniperus)
The juniper, one of the largest genera of trees, belongs to the cypress family and consists of about 50 to 70 different species. Junipers are known to be conifers — meaning they are trees that bear cones and needle-like or scale-like leaves that are evergreen. These bonsai trees are very popular when compared to their other bonsai relatives. This is because they are quite easy to train and shape.
Some of the most common Juniper Bonsais with scale-like foliage are the Chinese Juniper (Juniperus Chinensis) and the California Juniper (Juniperus California). Common Juniper bonsais with needle-like foliage include the Japanese Garden Junipers (Juniperus Procumbens), the Japanese Shimpaku (Juniperus Sargentii), the Rocky Mountain Juniper (Juniperus Scopulorum), and the Sierra Juniper (Juniperus Occidentalis).
Typically you’ll want to place your Juniper outside, however they can survive indoors with proper care. This type of bonsai tree requires lots of sunlight ranging from 5-7 hours per day. If you happen to be located in an area with harsh winter months then you’ll want to place your bonsai indoors during the winter season for protection. A good temperature guideline to follow for keeping your plant outside is:
- Below 25ºF — Bring your tree inside. As temperatures begin to reach below freezing your bonsai could suffer and potentially die off if the winter season is cold enough.
- 30º to 80ºF — Ideal for sunlight exposure and growth.
- 85º or more — Bring your plant inside. When hot summer months are in full effect your bonsai will start to suffer around this range and frequent exposure in the high 90’s and 100’s can be fatal to your tree.
Keep in mind that Junipers do require a certain level of humidity for optimal growth. Your bonsai may require extra care if you live in a more arid climate.
A good way to check if your tree needs watering is to feel the soil. Does it feel slightly dry? If so, it needs to be watered. Does it feel damp? Your tree is doing okay and doesn’t require any more water at the moment. Is there standing water on the soil? This is not a good sign as you’ve probably drowned your green one in excess water and their roots don’t appreciate this. Juniper bonsai trees don’t require constant watering, but when you feel dry soil you should water it. Be careful! Just as you can overwater your plants, letting them become too dry will also have consequences.
Whether your bonsai possesses normal scale-like foliage or has needle-shaped foliage, you should be kind to it by spraying it with a bottle to moisturize it with a gentle mist. This is especially beneficial after repotting your miniature trees because it will increase the air humidity levels. Similar to watering your coniferous tree, you should be careful to not overdo it with misting as well.
When it comes to fertilizing these popular trees you may come across many different answers for how often to fertilize them. Lucky for you, we’ve done a bit of digging and have everything you need to know. So, how often should you fertilize them? Generally, you should use organic fertilizer pellets every 6 weeks during growing season (spring to late summer) and every 4 weeks for the remaining months such as fall and winter. For inorganic liquid fertilizer you should feed it every other week, bi-weekly, in the growing season and weekly for the remaining months. It is recommended to use fertilizer at half-strength for best-results.
Need help finding a balanced fertilizer for your bonsai plants? Shin Nong PRO ORGANIC created Bonsai Food specifically for all you miniature tree lovers out there looking to help grow your little ones into strong, healthy trees.
Bonsai growers take notes here! You should prune your tree, but must be careful and well informed on proper pruning techniques. In order for your root structure to be able to support the branches above regular pruning is a necessity. You can’t simply take scissors to your bonsai leaves as if trimming a bush in your yard. If you were to snip anywhere else but at the base you risk damaging the new growth. Find you a pair of sharp scissors, pinch the ends of fresh growth, and cut at the base. Do this once every 6 weeks for proper shaping and to create those long, bushy shoots we all admire. While the Juniper species can handle aggressive pruning, be mindful to keep some foliage on all branches you wish to keep alive because if too little is left it is unlikely to bud again.
The excess roots of your tree will also need to be pruned every other spring. It is easy to do when you are repotting your tree. Simply cut about one third of the roots all the way around the root ball and up from the bottom. After cleaning it up you will then proceed to repot your plant which we will discuss how to do in a moment. There are many benefits to pruning such as preventing root damage or root rot while also promoting root growth and root strength.
After a couple years your Juniper will use up all the available nutrients from the soil it grew so well in. It is necessary to repot your tree every 2-3 years into a new, fresh soil mixture. Be gentle when removing your tree from its current soil mix and lightly begin knocking away the soil from around the roots and pot. Place new soil, regular garden soil will suffice, into the pot and carefully insert your tree back into the pot. Make sure to get out any air buildup within the new soil by carefully packing the soil down. Lightly mist your bonsai after relocating it to its new home.
Pests & Diseases
Generally, Junipers are pretty resistant to pests, but this doesn’t eliminate the possibility. A well taken care of bonsai that is pruned when necessary, has exposure to direct sunlight, and receives consistent watering has less of a chance of contracting pests or diseases. It is especially important to check your tree in the winter months as bonsais tend to get more sick when there is little sunlight. If your Bonsai does become home to pests it will typically be mites, juniper aphids, juniper scale, and/or juniper webworms. Spraying plant insecticide once a month can aid in preventing this, but it is recommended you find the cause for developing one of these issues should you experience such a problem.
Ultimately, these types of bonsai trees are great companions to spruce up your home or garden. If you would like to learn more about other bonsai tree species then check out our previous article where we discuss the top 10 most popular bonsai types.