Some trees react to a change in location and situation (look at serissa for example). It stresses them for a bit, but they usually adapt well enough. If you've had it for four months and it's only showing a few yellow leaves, I wouldn't worry too much. Moderate the watering a bit and it should be fine.
When it's said that a tree 'likes a lot of water' it really means they are just more sensitive to a
lack of water. In the vast majority of cases the differences amount to a narrow margin of conditions around the roots that ranges from 'damp' to 'moist'. Except true swamp and bog growers, no tree likes their roots to be actually 'wet' for long.
Roots grow in the air spaces between soil particles. The ideal environment for roots is saturated air rather than water. Our aim is to keep the potting substrate (whatever we use) moist enough that the air in the spaces remains saturated (100% relative humidity). This is why the particle size of potting substrate is important.
Water is a strange substance with odd characteristics that we take for granted because it’s so common (e.g. it’s the only one in its chemical class to exist in a liquid state between 0o and 100o C. All others in the same class are gas). Water is both adhesive (sticks to other stuff) and cohesive (sticks to itself, which is
why it exists in a liquid state).
When we water our trees, water adheres to the individual substrate particles. If the particle size is too big, the water is spread too thin to keep the air saturated (it will evaporate too quickly). If the particle size is too small the water adhering to each particle will also cohere to itself, filling the spaces and the roots drown.
The ideal size means that when watering, the air spaces fill temporarily, but the cohesion of water to itself means that water draining will pull out water from the spaces (pulling in fresh air), leaving each particle with a layer of water adhering to it and this evaporates slowly into the spaces keeping the air in the space at 100% RH. At 100% RH the water adhering to the particles won’t evaporate, but as the roots take water up, the RH drops and water will then evaporate into the spaces to make up the difference down a humidity gradient.
As well as being adhesive (sticks to other stuff), water is cohesive (sticks to itself). This means that that water in any given porous medium behaves like a column. The taller the column, the greater the downward pressure (i.e. water at the bottom of the column is being pushed down by the mass of the water above it, but water at the top is also being pulled down by its cohesive bonds with the water below it).
What this means for bonsai growers is that other things being equal (i.e. potting substrate) a tall pot or deep pot, will always drain more effectively than a shallow pot.
The upshot is that If your beech is in a shallow pot, it's roots will stay wetter for longer after watering (evaporation notwithstanding) than if it was in a deep pot. This is why tilting the pot (i.e. increasing the height of the water column) will assist drainage.
Knowing this stuff about the adhesive and cohesive nature of water helps us to adapt our substrate and watering to suit individual conditions. For example, if we use a tall cascade pot, we can use a finer potting substrate to compensate for the increased drainage, or water more frequently. Conversely, if we use a very shallow pot, we can use a larger grain size to improve drainage.
Sorry for going on a bit. I’ve cut and drilled the timber for two more display benches, but it’s raining and I can’t put them together until it stops, so I’ve nothing better to do
.
Re your deshojo: If it's a good tree, worth the money and you really like it, the
only appropriate time to buy it is 'now'
