There are many reasons why your Bonsai Tree might not be looking healthy. When a tree is not healthy, it will show you one way or another. With my first tree every time I noticed a change in its appearance my first reaction was to thing that I had done something wrong (my biggest concerns where always over and under watering .However over time I realized through my own experience and asking other people who have been keeping bonsai for a while that some of these will be simple issues that can be sorted very easily bit other times it might be the symptom of a more serious under lying problem. In fact there are times when changes on a tree are actually natural for that species.
However sometimes even if you are following the right care and instructions for your tree,it might still look healthy.So I guess the question is when you should worry about changes to your plant and what should you do about this.
This article provides tips on how to observe your plant so that you can realize as soon as possible when something is wrong with it, explore the causes of some of some problems for example when you notice that the bark is peeling or drying up and lastly how you can remedy the situation.
How to spot if your Bonsai is not healthy
Observing the plant
Know your plant
Information about your plant serves 2 purposes; firstly you will know what behavior is expected so that you do not worry unexpectedly for example most deciduous tree will lose their leaves in the autumn/fall and the bark of some species like Chinese Elm typically peel.Secondly, knowing about what your tree is susceptible to can help you take measures to prevent it. For example Fukien Tea are more susceptible to scales.
Every time I water a plant I give it a quick look over to check if it is doing fine. This does not take a long time at all and it well worth it because it will help you catch any problems/issues early on.
Below are some changes that I generally look for.For the most part, a plant will show you when it is not healthy. Things to look out for include;Watering time is an excellent time to give your plant a quick once over to check if it is healthy
I check both the top side and also the underside since sometimes insects can hide there.Somethings to look out for
- color changing out of season turning yellow or brown, developing spots
- pests and disease
- leaves drying /dying
- leaves falling off
- leaves getting holes
Branches and trunks
Next I look at the branches and trunk of the tree
- check for dry branches
- pests and diseases
- trunk appearing very dry /rotten
- bark peeling off
For potted plants often times the only area you can observe is the top soil. This is what I check for
- Before watering, I check moisture level to make sure water is actually required
- any insects/bugs crawling on the soil
- Re potting is a great time to check the plant roots to check if they are healthy
Although some tree species like Chinese Elm will naturally peel their bark in large patches, sometimes the condition if the tree trunk might be a sign that there is something wrong. Signs to look include; bark peeling/falling off, trunk appearing dry, looks like it is dying.
If this is happening to your tree, check whether the trunk still has a green cambium layer by using the point of a sharp knife to lightly scratch it. A green cambium means that it is still alive.
Bark peeling could also be caused by pests that hide under the bark of the tree. For tips on how to tackle disease and pests please see the section further below in this article.
You might notice changes in the leaves of your trees including; leavings turning yellow or brown, drying up or becoming crispy. Sometimes leaves will fold up or start falling off the tree. Keen observation of leaves might also reveal that pests/bugs have taken up residence.This section will explore some of these.
Over watering and under watering
For a plant kept indoors, yellow leaves might be a case of over watering. If you suspect that you have been over watering, reduce amount of watering and observe if this makes a difference.
One common way of ensuring that you water the plant only when needed. Before watering check that the tree actually needs water stick a chopstick into the soil, remove it after a few minutes, it is dry then go ahead and water but if it’s wet to the touch them leave it for some time
Another thing that leads to too much water is when the soil does not have good drainage, the solution for this would be repot the plant with fast draining bonsai soil. For plants pots that have trays, do not let the plant sit for too long in a tray filled with water.
Over watering can cause white mold on the soil. This can be removed with a tooth brush and water
Change of environment/location
Another reason for leaves changing color could be that they have been exposed to conditions that are detrimental to their health. An example is when tropical and sub-tropical plants are exposed to frost or plants that naturally prefer shady conditions being exposed to too much sunlight.
Yellowing or falling leaves be due to seasonal changes for that species for example deciduous trees losing their leaves in the fall.
Sometimes the real problem with the plant might be lower for example Problems with the root of a tree which needs to be repotted in a larger container or it might be that the soil drainage is not good.
There might be a mineral deficiency which can be remedied by adding fertilizer to the soil. It should be noted however that over fertilization can lead to the plant getting too much sodium.
When bugs or disease attack the plant often times the leaves will be the ones to suffer.