Can anyone help me identify this tree and tell me exactly how much water I need to give it?
I leave it out under direct sunlight, as it was when I bought it. (Shop staff had absolutely no idea what species it was or how much water. Was not a plant shop)
Both plants appear to be the same species of Hawaiian Scheffelera. More details can be found in this answer here. Native to South East Asia they are not frost hardy and should be kept indoors with bright indirect light and watered weekly.
I think the shop staff must have been very happy to sell this plant to you as, by commercial standards, they have not been treated well.
You can see dead stems and roots on the surface of the pot. This plant was shipped from the grower some time ago and then grown under low light. This is why you have such long stems with a few leaves at the end.
I recommend repotting the plant and cutting it back so all the stems are between twelve and twenty centimeters long. This plant responds well to being cut back and will look a lot nicer when the foliage is bushy
Scheffelera Why do you have the branches held up by twine? Your plant needs to be up potted, potting soil in a new pot at least 6" wider in diameter.
Kevinsky is right, you need some pruning to shorten the length of the branches and get rid of the twine. Shortening the length of the branches takes excess weight off branches unable to hold up the vegetation. Twine only makes weaker branches (think cast on a broken arm).
A bit of balanced fertilizer.
Water the new soil, newly up potted plant, allow to drain, dump any water that collects in the saucer. FEEL the heft of that pot well watered. Only water when you are able to feel a measurable lightness. Use only potting soil, no rocks or gravels below the soil and above the drain hole. Do not water every day. Lift the pot and feel it's weight. Very soon you will know what the heft of that pot and soil and plant are when it needs to be watered.
There aren't 'amounts' of water such as a recipe to be able grow a certain plant. You need to know when your plant NEEDS water, what your plant shows when it needs water. We humans only fail when we try to make plants fit within OUR schedule. An obvious lighter pot signals quite well when to water again. You'll learn YOUR plant's needs.
