When properly cared for, bonsai trees are beautiful and healthy. But sometimes problems arise, which cause the tree to lose its leaves. The loss of leaves on a bonsai is not uncommon, and as soon as you know the cause, you will be able to revive the tree. 

Common reasons why your bonsai may be losing its leaves include problems with the environment, watering, pests, and stress. All of these problems can be fixed fairly easy, especially if caught early enough. Don’t worry! We will tell you exactly how to fix these issues, and your tree will be back to normal in no time.

How Environmental Factors Can Cause Bonsai to Lose Leaves

The amount of light a bonsai tree receives is crucial to its health. The temperature of the bonsai’s climate is also very important. So, without proper light or temperatures, it is possible your bonsai’s leaves will drop. 

Indoor bonsai need to stay inside all year round in order to survive. Temperatures indoors should be kept fairly high (at least 60 degrees Fahrenheit). Additionally, tropical and subtropical trees, indoor trees, need to be inside so that they can receive plenty of light without being exposed to the cold. If your bonsai is outdoors, the climate must be well suited for your particular bonsai.

So, your bonsai’s leaves may be dropping because your bonsai is positioned wrong, is not receiving enough light, or is in a climate with temperatures that are too low or high.

How Over-Watering Can Cause Bonsai to Lose Leaves

A very common reason your tree may be losing its leaves is over-watering. Issues will arise if over-watering is done constantly, but not if it is occasional and irregular. 

One clear sign of over-watering is soggy soil. Bonsai rarely need to be watered more than once a day. Only water your tree when the soil gets slightly dry. When watering, stop when the water drips out of the drainage holes located at the bottom or sides of the pot. 

It is possible that the reason your tree is over-watered is not because of your watering schedule but because of the tree’s soil. Your soil needs to be water-retentive, but also well-draining. A soil that is not well-draining will store too much water, rotting the tree’s roots. Consider repotting your tree in better-draining soil if you believe this is the case.

How Under-Watering Can Cause Bonsai to Lose Leaves

The exact opposite of over-watering, under-watering is another major problem bonsai growers face. Under-watering could very well be the reason your bonsai is losing its leaves. 

If you find yourself forgetting to water your bonsai or are watering it only once or twice a week, under-watering is likely the reason the leaves are dropping. The bonsai’s leaves will likely not only drop, but they will be withered up and dry. The branches and trunk will also be dry.

The first thing you must do if your bonsai is under-watered is dunk the soil in water. After you do this, it is crucial that you start watering as soon as the soil gets slightly dry every day or two. 

Just like with over-watering, is possible that your tree is under-watered because of the soil, not your watering routine. In this case, the soil will not be water-retentive, meaning not enough water is soaked up when you water. If this is the case, repot your tree with a well-draining, but water-retentive, soil.

How Pests Can Cause Bonsai to Lose Leaves

Pests and diseases are another likely cause of dropping leaves on bonsai. Pests can include critters like scale, spider mites, aphids, and many more. They can be removed with specific pesticides or, in some cases, ladybugs! Don’t think that ladybugs are bad for your bonsai; they actually eat the pests on your plant without hurting it in any way. 

Bonsai’s leaves dropping can be caused by a number of things. These factors include but are not limited to watering problems, insufficient light, wrong temperatures, and bugs. If the conditions are unsatisfactory for prolonged periods, it is unlikely that your bonsai will survive. But, when these problems are caught early, your tree can recover.