Watering is a fundamental part of all plant life. Without water a tree will die, in a dry bonsai container a tree will die of thirst in as little as 48 hours. Too much water will “drown” your bonsai. Many new bonsai gardeners will panic and over water. Over watering kills Bonsai more than all other causes combined.

The first and only rule to learn is this: Water thoroughly, but only when a bonsai needs it.

So the question is, how can you tell? A simple answer is that healthy roots colonize the entire pot apart from a thin surface later in some cases. This means that the soil dries fairly evenly throughout the pot.

Scratch the dry surface to expose the soil immediately below, if the soil just below the surface is clearly wet, your bonsai tree doesn’t need water 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 reasonably accurately just by looking at the surface of the soil. Too much scratching the surface of the soil will compact the roots, so if you are still unsure try the stick test. Insert a wooden stick into the soil in one corner of the pot, push it right 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.

The best way to water your Bonsai tree is from above, using a fine rose on a watering can. Ordinary tap water is fine in most cases unless you are growing a lime hating species such as azaleas, which need an acid soil. If you live in a hard water area they will need regular applications of a soil acidifier such as Miracid.

Fertilizer

Bonsai soil is largely inert containing little to no nutritional value to the bonsai tree.

What nutrients may exist are soon washed away with daily watering.

Your bonsai is entirely dependant upon you for its nutritional requirements.

What fertilizer should you use? There is a vast array of fertilizers. All of them claim to be the best for one reason or another. In truth, the basic ingredients are all pretty much the same although the proportions may vary. The proportions of the three basic nutrients Nitrogen (N), Phosphorus (P) and Potassium (K) are much more important than the brand name or type of fertilizer.

Somewhere on each package of fertilizer will be the initials NPK followed by three numbers. This indicates the relative proportions of the three basic nutrients. (for example,

PK 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 will become pale and the stems will be thin and weak. Both stems and leaves will be more susceptible to fungal disease.

Phosphorus (P) manages root development and helps ripen the fruit on the bonsai

which have berries.

Potassium (K) (potash) is involved in a balancing act with the nitrogen. It hardens off the young growth and protects it against fungal attack and cold damage. Not enough potash can result in mottled foliage, can cause burning of the leaf margins and result in premature autumn leaf fall.

The proportion of nutrients to use will depend on the time of year. In spring a weak blend of EG 5-5-5 will be all your tree will need. As the shoots begin to extend your tree's nutrient requirements will increase and you should step up to EG 15-15-15.

Starting toward the end of summer and through early autumn, you will want to use a nitrogen free fertilizer EG 0-10-10. This will help harden off the buds and roots and get the bonsai tree ready for winter. The exception to this rule is the pine family.

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 the next year.

Light

Daylight is essential for plant survival. It is important to understand the difference between sunlight and sunshine. Direct sunlight can be too harsh for many species of bonsai. All bonsai trees will benefit from some degree of dappled shading from the hot summer sun.

Given the proper care, a bonsai tree will last for many years. In some cases they will even outlive their owner! Good bonsai tree care is not rocket science…it does take a bit of knowledge and persistence, but the reward is definitely worth it.