Watering is a natural thing with regard to taking care of house plants. In the case of the Bonsai, nonetheless, it is by no means easy. It is difficult to give general advice, since amount and frequency of watering depends on many factors such as the species of the tree, its size and shape, the sort of soil it grows on, the size of the plate, the weather, amount of light and humidity.
When to water
The best thing to do is to feel with the tip of your finger in the soil whether it is dry or not. Water only when you find the soil to be dry. Be careful not to give your Bonsai too much water, for the rotting of the roots is the foremost plant disease.
How to water
Pour the water slowly on the ball of earth. For Bonsai you will have to learn to be patient. Wait for your Bonsai to take in the water before you pour in more. Give it the chance to soak in the water. Do not water your Bonsai in the afternoon, for the water on the leaves will intensify the incoming light, which could cause a burn. Plus, when you give water, the soil will suddenly cool, which could cause damage to the roots. Therefore, you had better use lukewarm water or wait for the falling of the night, so that the air cools as well. The best time to water your Bonsai is late at night, so that it has all night to absorb the water. If you are a perfectionist, use rainwater instead of water from the tap. You can collect rainwater in buckets during showers, and then pour that into your watering can.
2. When and how often do I fertilise my Bonsai?
Fertilising your Bonsai is of great importance, for it is restricted to growing in relatively small plates where it cannot find much nutrition. If you fertilise regularly and in correct amounts, you can make sure your Bonsai grows healthily and well composed.
When to fertilise
You can fertilise most Bonsai plants from April to October. If you use solid fertiliser, you can apply it once a month, and if you use liquid nutrition, you can apply it once every week. If you want to treat your Bonsai really well, you should use solid fertiliser for the soil and the liquid variety for the leaves of the Bonsai tree. The Japanese dissolve liquid fertilisation in water and spray the mixture carefully on the Bonsai leaves. This way you will not overtax the root system. Do not use too much fertiliser: use only half of the amount you would be advised to use for other house plants.