Bonsai Basic Care
Watering is fundamental to all plant life.Without water a tree will die, in a bone dry bonsai container a tree will die of thirst as little as 48 hours.That is where most new commers make thier first mistake, more bonsai are killed through panic over watering than any other causes combined.
When to Water
The first and only rule to learn is this: Water thoroughly but only when a bonsai needs it.
The real question is, how can you tell? The simple answer is healthy roots colonise the entire pot apart from a thin surface layer in some cases.Which means that the soil dries fairly uniformly throughout the pot.
Scratch test Scratch the dry surface to expose the soil immediately below, if the soil just below the surface is clearly wet, your bonsai tree do not need watering yet.If it is damp you can water, if it is dry you must water.
After a few weeks you should be able to judge reasonable accurately just by looking at the surface of the soil.Besides to much scratching away at the surface of the soil will compact the roots, so if you are still unsure of your judgement try the
Stick test Insert a wooden stick into the soil in one corner of the pot, push it ridght to the floor of the pot and leave it there.Withdraw it every day and feel the end.This will tell you how damp the soil is at all levels.
By far the best way to water your Bonsai tree is from above, using a fine rose on a watering can.Using ordinary tap water is fine in most cases unless you are growing a lime hating species such as azaleas which needs an acid soil.If you live in a hard water area they will need regular applications of a soil acidifier such as Miracid.
Bonsai soil is largely inert containing little if nothing of nutritional value to a bonsai tree.What nutrients may exist there are soon washed away with daily watering.This means your bonsai is entirely dependant on you for its nutritional requirements.
Which to Use? There is a bewildering array of plant foods available all of them claiming to be the best for one thing or another.Yet in truth the basic ingredients are all much the same although the proportions may vary.The proportions of the three basic nutrients Nitrogen (N), Phosphorus (p) and Potassium (K) are more important than the brand name or type of fertilliser.
Somewhere on the pack of every fertillser will be the initials NPK followed by three numbers.This indicates the relative proportions of the three basic nutrients.EG.NPK 15-15-15 indicates a balanced feed of medium strength.
Nitrogen (N) is responsible for leaf and stem growth, with too little nitrogen the leaves become pale and the stems are thin and weak and both become susceptible to fungal disease.
Phosphorus (P) takes care of the root development and also helps the rippening of the fruit, the latter is especially important in the case of bonsai which have berries.
Potassium (K) (potash) plays a balancing act with the nitrogen.It hardens off the young growth and protects it against fungal attack and cold damageToo little potash can result in mottled follage, burning of the leaf margins and premature autumn leaf fall.
What NPK? The proportion of nutrients to use will depend on the time of year.In spring a week balanced is all your bonsai tree will need.EG. 5-5-5.Then as the shoots begin to extend the bonsai tree’s nutrient requirements will increase EG. 15-15-15 or there abouts.Towards the end of summer and through early autumn a nitrogen free fertilliser EG.0-10-10 helps to harden off the buds and roots in readiness for winter.The one exception to this rule is the pine familly.Pines need low nitrogen diet in spring and early summer, followed by a high nitrogen diet in late summer in order to build buds for next year.
Light and Air
Daylight or good artificial light is essential for plant survival.It is important to understand the difference between sunlight and sunshine.Direct sunlight can be to harsh for many species of bonsai especially through the glass window of a living room.All bonsai trees whether indoor or outdoor will benifit from some degree of dapple shading from the hot summer sun.
If you keep indoor bonsai you should place them near enough to a large window so they receive good light, but not where the sun will shine on them directly.In the case of outdoor bonsai maple, beech and larch are the worst effected by strong sun they will need semi shaded area.At the other end of the spectrum pines will be happy enough to bake away all day long in full sunshine.
Ventilation Make sure there is an air change in your room every hour if necessary a small fan would be useful.Stagnant air breeds mildew and other nasty fungal problems, disrupting the bonsai tree’s natural breathing rhythm and generally makes the bonsai look dowdy.