Taking care of a bonsai tree may seem complicated, and it sometimes can be.
However, anyone can raise a bonsai if they are willing to put in the work to care for it.
To take care of a bonsai tree, you’ll need to follow these broad guidelines:
- Determine whether your bonsai is indoor or outdoor
- Keep your bonsai in bright sunlight
- Keep your bonsai’s soil moist
- Keep your bonsai warm
- Re-pot your bonsai every 2-3 years
- Fertilize your bonsai soil
- Keep the right tools on hand
- Learn before pruning and wiring
But, just remember that these are general rules, and you will need to account for your bonsai’s species when you care for it.
In this article, we’ll look at the best care tips to keep your bonsai thriving for decades, or maybe even centuries.
How to Take Care of a Bonsai Tree
Determine Whether You Have an Indoor or Outdoor Bonsai
Before you do anything, you first need to determine whether your bonsai tree is an indoor or outdoor variety because its care instructions will vary based on this factor.
Indoor bonsai trees are most commonly subtropical or tropical tree species that require a warm, consistent temperature throughout the year.
Indoor bonsai trees also typically need more care and attention than their outdoor counterparts.
Popular species of indoor bonsai trees include ficus, Hawaiian umbrella, jade, sweet plum, and Fukien tea.
Outdoor bonsai trees, on the other hand, are hardier, and you can grow them in subtropical and Mediterranean climates where there’s less chance of frost.
And frost is a crucial factor to consider when purchasing outdoor bonsais because frozen roots will kill a bonsai quickly.
Furthermore, outdoor bonsai trees are often deciduous, meaning their leaves change color with the season.
Generally, outdoor bonsais do well in an area that has four traditional seasons, often going dormant in the late fall and winter months only to come back to life in spring.
Many outdoor bonsai require this dormancy period to survive, so they must stay outdoors or in a greenhouse.
Popular outdoor bonsai species include juniper, pine, Japanese maple, Japanese flowering cherry, cedar, ginseng ficus, weeping fig, and even pomegranate trees (yes, they grow fruit!).
Keep Your Bonsai in Bright Sunlight
Most species of bonsai trees need as much light as they can possibly get, despite whether they are indoor or outdoor trees.
Light allows your bonsai tree to photosynthesize for food and energy and respirate – its way of breathing.
For this reason, indoor bonsai growers often find that placing their tree in a south-facing window is the best bet for the most amount of indirect sunlight.
But depending on the bonsai tree species, it may require some direct sunlight for parts of the day.
In this case, an east-facing window might be your greatest option.
During the winter months, when there is less natural light during the day, consider investing in a grow light.
Grow lights can provide your bonsai with ultraviolet rays that it needs to survive.
Meanwhile, for outdoor trees, keep your bonsai in a bright spot that gets mostly sun but some shade throughout the day, just like a standard tree would require.
Keep Your Bonsai’s Soil Moist
You should water a bonsai as soon as the top layer of soil begins to dry out and feels dry to the touch.
The main reason bonsais die is that they don’t get enough water.
Thus, you need to be diligent about watering your plant.
The soil in a potted bonsai is very shallow, which is what helps keep your bonsai tree miniature.
But being in a small container also means the soil will dry out more quickly, so it requires constant monitoring.
Yet, every bonsai’s watering needs will vary by species and by where you keep the bonsai tree in your house or yard.
More sunlight means drier soil, and more humid environments mean the soil will stay moist longer.
For this reason, people keeping multiple bonsais should treat each plant individually.
Because, for instance, some bonsais need daily watering, while others only require water every two to three weeks.
When watering your bonsai tree, keep pouring water evenly over the soil until some water begins to drain out of the drainage holes at the bottom of the pot, then stop.
Watering in this way will saturate the root system with the right amount of water.
But, if you notice the leaves beginning to turn yellow on your bonsai despite consistent watering, you’re likely overwatering your tree, and your bonsai’s roots are too wet.
Pull back watering in this case.
Keep Your Bonsai Warm
Indoor bonsai trees do best when kept in daytime temperatures of 64 to 75 degrees Fahrenheit (18-24 C) and 57 to 60 degrees Fahrenheit (14-16 C) at night.
Luckily, for most homes in North America, this temperature range is pretty standard.
However, bonsai tree growers should always remember to set their thermostats when they’re not home to keep this constant temperature.
Bonsai trees do not do well with big temperature swings, so keep this in mind if you’re on vacation or outside your home for long periods throughout the day.
Meanwhile, for outdoor bonsai trees that thrive in four seasons, let nature be your guide.
The only time you should move your bonsai indoors or to a shed or greenhouse is when you expect large temperature swings or frost.
And like I said earlier, you need to protect your bonsai roots from any potential freezing.
Re-pot Your Bonsai Every 2-3 Years
You’ll need to re-pot your indoor bonsai tree every two to three years to keep it healthy.
However, you may need to re-pot more or less frequently depending on how fast your species grows.
Generally, you should keep the height of the container about ⅔ the height of your tree.
For this reason, a growing bonsai may need a larger pot upon re-potting.
To re-pot your bonsai, you need to use shears to cut away approximately a third of its root system and any roots sticking up through the soil.
In addition, cut away any roots that appear to be rotting.
Any excess roots that grow during this two-to-three-year period can ultimately starve your bonsai if you do not remove them.
Then, after cutting, clean up the original pot if you plan to reuse it and replace the mesh squares covering the drainage holes.
Add new soil to the bottom of the pot, insert your newly trimmed bonsai, and fill in the remaining space with additional soil.
Fertilize Your Bonsai Soil
Bonsai soil should consist of a mix of approximately one-third akadama, one-third pumice, and one-third lava rock to allow for good drainage.
Soggy soil is a recipe for mold, fungus, and root rot, which can be fatal for bonsai, so drainage is absolutely necessary.
Bonsais don’t need a ton of fertilization, but due to their confinement in a small pot, they will need a little assistance since they can’t use their roots to look for nutrients deeper in the soil.
Experts recommend replenishing the soil once a week or every other week during the growing season (typically April through September), using a fertilizer that contains nitrogen, potassium, and phosphorus.
And you need all three of these ingredients so that your bonsai can remain healthy.
Nitrogen will help your bonsai grow strong branches.
Potassium will improve your bonsai’s response to stress and help it fend off disease.
Phosphorus, meanwhile, will be essential for flowering bonsais and will help your bonsai develop healthy roots.
Generally, you’ll find fertilizers in both liquid and solid form, and either can work for your bonsai.
If you choose a liquid fertilizer, you will need to apply it over wet soil.
Solid fertilizer will come in pellets, which you can mix into the top layer of soil, where they’ll release their nutrients with every watering.
And don’t forget that, as with overwatering, overfertilizing is a genuine concern.
If the leaves on your bonsai begin to turn yellow, wilt, or drop from the tree unseasonably, you could be overfertilizing your bonsai.
Keep the Right Tools on Hand
To keep their bonsai in tip-top shape, bonsai growers should always have concave cutters, pruning scissors, tweezers, and wire on hand.
In addition, you may want to keep extra pots with drainage holes around if your bonsai needs replanting.
Also, liquid or solid fertilizer is good to have during growing months.
Learn Before Pruning or Wiring
Even if you purchased your bonsai tree already wired and pruned to perfection, at some point, you would likely need to prune it or rewire it.
But, before you do this, read guides such as this one to learn more about the process before you jump in.
Overall, caring for bonsais is a craft, meaning you can easily ruin it if you try to prune or wire without knowing how to do it correctly.
Thus, to maintain your bonsai, you need to know some basics about pruning and wiring.
Pruning includes cutting back new branch shoots and leaves to allow the inner parts of your tree to thrive or cutting off new buds to keep the leaf structure dense and compact.
In addition, your bonsai may require some structural pruning and wiring to keep its shape intact.
However, never do any structural pruning or wiring, which involves cutting off larger branches and rewrapping others to grow them in different directions unless your bonsai is dormant.
Bigger pruning jobs on a dormant tree allow you to see the branches without leaves getting in the way.
It also allows your bonsai to heal from any pruning wounds as spring arrives.
Learning how to take care of a bonsai tree is a process that requires following the above instructions.
But, you’ll probably also go through some trial and error while you’re learning how to care for your tree.
Species choice aside, many factors can shape how you take care of your bonsai, including the climate, pot, soil, fertilizer, pruning, and wiring techniques you’ve chosen to use.
Thus, providing for your tree is not always straightforward.
Yet, that’s why a healthy, thriving bonsai tree is so rewarding.
You know that you have worked hard to give your tree everything it needs to live its best life.
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