Common Problems

It is always best to avoid problems in the first place through preventative measures.  This website provides all the information you need to prevent your tree from suffering from disease, however not everything can be prevented.

The easiest way to prevent problems with your bonsai is to make sure that your tree:
1.     is watered the right amount
2.     is in the right environment (location (indoor v. outdoor/ sun v. shade)
3.     and soil are clean and free from dust and debris
4.     your tree has enough ventilation, fresh air, and sufficient light
5.     your tree is adequately fertilized
6.     is regularly pruned and re-potted
7.     is regularly inspected for pests

Over or Under Watering

More bonsai are killed by improper watering than by all other causes combined. Bonsai soil should allow for water to drain freely but still allow for some moisture retention. If you over water your bonsai may suffer from a condition known as Root Rot which is often fatal. Under watering is also a common problem, because although it may seem that watering every day or every second day should be enough, you must consider the fact that bonsai containers are small and shall which makes it easy for retained moisture to evaporate. Check daily or even a few times daily (depending on location) for moisture and water as necessary. See our Watering page for proper watering techniques.






Leaf Loss

Besides the fact that deciduous trees will naturally lose their leaves in the fall and regain them in the spring, sometimes bonsai loose leaves or become discolored for various reasons. Leaves are most likely to fall off after repotting if too many roots have been cut off and the tree is no longer able to support the leaves it had. Remember to keep the root mass proportionate to the leaf mass to avoid this problem, and never cut off more than 1/3rd of the tree’s roots. Another reason could be due too much sunlight. If you do not protect your bonsai with a shade screen or put it in partial shade, some leaves may become scorched by the sun. Unfortunately you cannot save these leaves, but don’t pull them off. Keeping them on protects the tree from damage to the layer of leaves underneath. Simply cover the tree or move it to avoid sun scorch. Another reason for leaf loss or discoloration could be lack or overdose of fertilizer and/or water (see our page on Fertilizing). If none of these seem to be the case, look carefully at your tree and see if it is diseased or infested by some pests.






Pests and Disease

A bonsai is nothing more than a miniature version of a normal plant, therefore it can be treated with commonly found insecticides and fungicides according to directions on the package. Although most bonsai species are very hardy, some are still susceptible to disease and pests. Insects such as aphids, spider mites, scale, and root aphids are a common problem which can easily be corrected by sprays or soapy rinses. To maintain a healthy tree, it is a good idea to spray the entire tree with a systemic insecticide once a month throughout spring and summer.






Commercial Bonsai

Every month, we get multiple emails from distraught viewers of our website about dying or dead bonsai trees and about 85% of these trees are commercial bonsai trees that had rocks glued on top of the soil.  This is not a coincidence; these trees are destined to die within a couple of months, so please read on if you just purchased one of these or are considering to buying one.

Question: Should I buy a commercial bonsai tree with rocks glued on top of the soil?
A: No, please avoid these!

Reason:
Bonsai is an art, and like any art, the focus is to create the most beautiful and high quality piece possible. With that said, commercial bonsai are not technically bonsai.  They are mass produced house plants with an oriental flavor (you know, those figurines of Asian men fishing or little pagodas and cranes placed under the tree).  These “bonsai” trees are essentially produced by cutting off branches (cuttings) from a host plant (usually a juniper), rooting them, and then inserting them in a “bonsai” pot and soil.  These trees have no age, no quality, and zero personality.  Not to mention, they are very fragile and vulnerable.

To make things worse, these trees are often sold with gravel/ rocks/ pebbles glued on top of the soil.  The pebbles serve two functions.  First, they prevent water from evaporating from the soil so that the manufacturer, shipper, and the nursery does not have to worry about watering these trees as often.  Second, the glue or lacquer on top of the gravel keeps the soil and gravel in place so that there is no spillage during shipping. This is very beneficial for those making money, but the outcome is disappointing to buyers. 

Most plants, especially bonsai, do not like soggy soil, hence why bonsai pots have large drainage holes on the bottom and good draining soil is required (see our pages on Pots and Trays, Soils, and Potting).   When a bonsai’s roots are exposed to too much water, the roots will rot and/or a fungus will grow.  This is usually deadly and the tree cannot be saved (see Common Problems).  The number one killer of bonsai trees is root rot because of over watering.  When you have glued on gravel on top of the soil, the moisture is locked in, oxygen exchange is inhibited, fungus grows, the roots rot, and the tree dies.  The glue that comes with these commercial bonsai is water based and is supposed to dissolve with time, but the problem is that it takes too long to dissolve and the bonsai is usually dead by then. 

This is all quite unfortunate and it discourages many beginners to bonsai.  If your tree has died, please do not be discouraged.  All bonsai experts have killed many trees and these commercial trees are destined to die fast.

  Left: Healthy Roots              Right: Root Rot

Elm (outdoor bonsai) suffering from too much moisture, because it was kept indoors.

Plant suffering from scale.  Scale and mites can be killed by spraying the plant with isopropyl alcohol. You can remove the dead bugs with a damp towel.  

This is not a bonsai! This is a twig in a pot with a random Asian figurine! Also, please note the glued on rocks. 

Here is another example of the glued on rocks.

And this one is probably as ugly as they come...