Bonsai Basic Care Guide
If you’re here, you have likely received a bonsai tree as a gift or have just purchased your first tree. Congratulations—this hobby is very rewarding, and I’m sure you will have a great time with it. But you’re not here for the congratulations; you want to know how to care for your tree to avoid fatal mistakes. Let’s not waste any more time and jump in.
Sunlight
This is very important. Trees need direct sunlight to photosynthesize and create glucose, which is their food source (not fertiliser—that is nutrients). It is important that this is direct sunlight, not sunlight through a window or plastic sheeting on a patio roof. The UV-B rays need to hit the leaves directly. Don’t get caught by the common misconception that if your tree has light, it is photosynthesizing—it needs direct sun.
Place It Outside
If you place it outside, you will cover tip #1, but being outside is also important because a large percentage of the trees we use in bonsai are temperate species. This means they use seasonal triggers to move through different stages of growth, including temperature changes, daylight length, and UV intensity. This tells the tree when to grow and when to be dormant.
If your tree is inside, this can confuse it, as you cool the house in warmer months and heat the house in cooler months. The tree also can’t sense changes in daylight length or UV intensity. On top of this, airflow is important for your trees as well, which they seldom get indoors.
Smart Watering
This is the part where people usually go wrong, and it’s partly due to badly delivered advice. The advice itself isn’t bad—just how it’s delivered. It usually goes something like this:
“Don’t let your tree dry out, but don’t let it stay wet.”
Confusing, right?
What this actually means is that trees in bonsai pots need a good balance between water levels and oxygen levels. Too much water in the pot leads to standing water and eventually root rot. Not enough water results in too much oxygen, which causes the roots to dry out and die.
For watering, this means you need to allow the tree to get rid of excess water (physical standing water) between waterings, but don’t let it go so long that the soil completely dries out. What you should end up with is soil that is moist—this is a good balance of water and oxygen.
Most watering issues come down to frequency: either too much or not enough. It’s important to understand that watering frequency is almost never the same. Some days are hotter, some are cooler, and some have more wind present, all of which affect how often a tree needs watering. Other variables include soil type, pot size, tree health, and foliage density.
For now, the best lesson is to practise the watch and act method—go out, check your trees, and water accordingly.
One last point is the volume of water delivered to the tree. People often ask how much water they should give. You should water until the root ball is completely soaked—this usually means water will run out of the bottom of the pot. Volume is only an issue if you don’t give enough water to soak the entire root ball. On the other end of the scale, you could give your tree 100 litres of water in one go and it wouldn’t be an issue, except that you’ve wasted 99 litres. The soil will hold what it needs and drain the rest if the soil mix is good.
Fertilizing
When you start out, don’t get too hung up on this. Find a good, balanced, slow-release fertiliser and follow the manufacturer’s instructions. Getting particular about N-P-K ratios or timing becomes more important as you advance in bonsai, but for now, a good all-round fertiliser applied throughout the growing season is perfectly fine.
Pruning
At some point, you’ll get itchy fingers and want to prune your bonsai tree to feel like you’re doing bonsai work. However, it’s important to let the tree grow. Allowing the tree to put on new growth and photosynthesize creates a stronger tree.
Old growth becomes spent and doesn’t photosynthesize as well—similar to solar panels on a house roof that lose efficiency over time. Trees generally go through a 2–3 year cycle of leaves or needles. If you constantly cut off new growth as soon as it appears, you can weaken your tree, making it more susceptible to heat stress, cold stress, pests, and disease.
Allow your tree to flush, harden off, and make use of its new growth before pruning it back. This will result in a strong tree that responds well to bonsai techniques.
These are the basics of bonsai care. If you’d like to dive deeper into bonsai techniques and care, we offer bonsai classes available for instant download that are yours to keep forever. They’re a great way to accelerate your learning.
