I’ve always said that there are 3 main things that kill most bonsai
- Too much water
- Not enough water
- Keeping your tree inside for too long
The truth is, there are a few more things that can kill your bonsai, or effect it badly enough to set it back years.
The main one of these is the silent bonsai killer, PESTS.
Different varieties can be affected by different pests while some can be affected by them all.
PREVENTION IS THE BEST DEFENCE
Most pest infestations can be avoided by regularly checking your bonsai trees for signs of infection and dealing with it before it gets out of control.
Whenever possible I will water my trees by hand to allow me to get a close look at each tree to check for signs of pest on a regular basis.
Curled up or distorted leaves, sticky residue, trails of ants, a white powdery substance, small white or black spots are all a sure sign something unwanted is hanging out in your tree.
PREVENTION AND CURE
Most pest infestations can be headed off by spraying your trees lightly with lime sulphur during the winter months, this not only acts as a fungicide but will also kill off any dormant pests just as they become active as the growing season begins and they start to emerge.
RIDDING YOUR BONSAI OF PESTS
If you find pests on your bonsai, removal by hand wherever possible is always preferable. If this is not possible then start with the more natural pesticide products such as white oil or pyrethrum.
Don’t spray them on in the heat of the day and don’t lay it on too thick.
Both of these products will usually knock most pest on the head within a couple of days, so check your bonsai regularly to see if this has worked effectively.
STUBBORN BONSAI PESTS
On trees like Junipers where the scale gets in deep between the needles slowly sucking your tree dry, sometimes you will lose a branch before you even notice the scale is there.
In these cases you may need to use a systemic pesticide such as Maldison Plus, this has been the only thing I have found to be effective in combating scale on Junipers.
CHECK BEFORE YOU SPRAY
No matter which method of pest control you use, make sure you read the labels thoroughly and mix chemicals according to the manufacturers specifications, or you may end up doing more damage to your bonsai then the pests you are trying to eradicate.