Caring for indoor bonsai
Care of an indoor bonsai tree is different from that of normal potted house plants. The main reason is that bonsai trees are planted in small pots and therefore have limited storage for nutrients and water.
Temperature
A steady temperature rather than one which fluctuates a lot is highly recommended, so avoid draughts, or placing your bonsai on top of a shelf with a radiator underneath.
Light
Bonsais needs as much natural daylight as possible, but avoid direct sunlight which can scorch the leaves and speed up the water evaporation from the compost.
Watering
Your bonsai needs regular watering; it needs to be moist but not overly wet. The best method is to completely immerse the pot in water so the water level is above the soil. Wait until all the air bubbles have stopped rising, then place the pot on a drip tray. Water which drains off will evaporate and keep the foliage in a humid state. The warmer the room the more often you may need to water your bonsai. It could be once a day or once a week depending on the location. Test the surface of the compost; if it is moist wait a day or so then test again. Do not let your bonsai dry out completely or stand in water for long periods.
Problems & Solutions
Yellow or fallen leaves
If your bonsai starts to show a change of colour, with leaves turning yellow, do not be alarmed. This could be due to a number of reasons such as a shock to the tree caused by being very dry or very cold. If any of these have occurred, adjust the environment.
Depending on the species, fallen leaves could be a natural occurrence. The tree is not dead, but just going into temporary dormancy, so be extra careful with watering. Fallen leaves will be replaced by a new set of leaves four to eight weeks later.
Fungal diseases
Bonsai trees can be subject to fungal problems just like trees in nature. As soon as you notice problems use an appropriate fungicide
Pests
The most common pests are spider mite, white fly, mealybug and aphid.If your bonsai is affected, treat with a chemical or organic insecticide, following the instructions carefully.
Water does not drain through the pot
This is usually because the growing substrate has degraded and it indicates the need for repotting.
Roots are coming out the drainage holes or the tree is lifting out of the pot
This indicates the need to repot the bonsai and trim the main root.
Brown tips on leaf edges
This is likely to be caused either by sun scorching the leaf tips or soil drying out. Move to a shady position and/or water regularly.
Long, leggy growth
This is usually due to lack of light and new growth. New growth is drawn towards where light is. Move to a brighter position.
Pruning and Wiring
It is important to regularly trim your bonsai to keep its shape or style. This is called the ‘clip and grow’ method. When a new shoot has elongated, and has between six and eight new leaves, it should be trimmed back to two to four leaves. This may be every two months or so depending on the vigour of the tree. With regular pinching back the tree will fill out better.
Repotting
Indoor bonsai are best repotted in the spring every two years. Top pruning can be carried out consistently after repotting.
