Indoor bonsai is a relatively new idea which has not come from Japan. The center of interest appears to be Germany but the concept has now spread to other countries. You can buy indoor bonsai trees from garden centers and nurseries throughout Britain.
The basic difference from the traditional outdoor bonsai is that non-hardy trees and shrubs are used here. Indoor bonsai are generally much better suited than hardy types to the conditions found in the average home, and of course they must be kept indoors during the winter. Thus they can be regarded as true house plants, although during the summer months they should be given the standard bonsai treatment. This calls for keeping them outdoors and then bringing them inside for a few days at a time.
Obviously the easiest plan is to buy a mature and trained specimen but they are expensive. If you have the time and patience you can begin from scratch. Pot up the chosen seedling or rooted cutting in the ordinary way in a 3 in. pot and care for it.When the main stem has reached the desired height the growing point should be pinched out. Remove some of the lower branches and pinch out the tips of upper side branches to encourage bushiness at the head ofthe tree. After 2 years repotting is necessary and so is root pruning.
In spring remove the plant from the pot and cutaway about 1/3 of the roots – replant in a pot or bonsai tray. During the growing season continue to pinch out growing tips, remove unwanted growth, train branches with bonsai wire and cut off sun-scorched leaves. You will need to carry out this repotting and root pruning process every 2 years.
Like their hardy outdoor counterparts, indoor bonsai are fascinating to grow but they are a lot of trouble. Moist air is essential and you must keep them well away from draughts and radiators. Watering is the big problem – a daily soaking is often necessary. Feed every 4-6 weeks.
Fukien Tea (Carmona microfylla)
Secrets of success
Temperature: Average warmth.
Light: Most types require a brightly lit spot away from direct sunlight – all should be protected from hot summer sun.
Water: The compost must be kept moist (but not wet) at all times. This may call for daily watering – use rainwater or tepid tap water. The recommended method of watering is by immersion but overhead watering using a fine rose is generally satisfactory.
Air humidity: Moist air is vital. Stand the pot on a pebble tray and mist leaves occasionally.
Repotting: Repot in spring every 2 years. With a trained plant some of the old compost is removed from around the roots and 1/3 of the root growth is cut away. Replace in the same container, using fresh compost.