You may not know bonsai trees have a classification based on the dimension. It isn’t an absolute rule and the measure of the bonsai isn’t really important. No one should grow his bonsai thinking of the category it belongs to, yet it is important he has those basic notions that complete his bonsai culture.
Japanese people divided bonsai into groups giving them a name. A precise classification doesn’t exist, every bonsai master varies it a little. This one I present here is generic, but consider a tolerance of 5-6 cm (2-3 inches).
SHITO or KESHITSUBU: these are those little bonsai measuring around two or three centimeters (one or two inches), they are really difficult to cultivate and should be approached only by experienced people.
MAME: mame are little bonsai measuring no more than 10 cm (4 inches).
KOMONO: up to 15 cm (6 inches), these bonsai are still hard to manage as little parts may be tricky to handle.
KATADE-MOKI: those from 20 cm to 40 cm (8-16 inches) are called “one hand bonsai” because it’s the last category that can be handled using just one hand. These one are the most diffuse.
CHUMONO: “two hand bonsai” start from 40 cm up to 90 cm (16-35 inches) and are the most appreciated because their proportions are well balanced. In this category there are wonderful bonsai, the masterpiece of this art, the most admired and loved specimens.
OMONO: the last group presented here is the one up to 120 cm (45 inches). These are spectacular, but maybe they appear more like “normal” trees than bonsai. In this category there are breathtaking specimens for sure but this isn’t the group bonsai are famous for.