a) UPRIGHT: branches grow up and away from the central leader(s). The shape may be that of an open vase, a globe, an undulating figure, a cone or a narrow oval. It may be dense and twiggy or open and airy.
b) MOUNDING: branches grow away from the leader and curve down toward the ground.
Most upright growing maples have palmate (not the cut, lacey ones) leaves ('Seriyu' is an exception) while most mounding maples have dissected or cut leaves ('Jiro Shidare' is an exception). Some upright growing trees will develop cascading branches when mature ('Omure yama' is an example).
Sizes are described in terms of feet (') or meters (M) and predict approximate height at maturity, 10 to 15 years.
Zone: The U.S. Department of Agriculture developed these standard geographic divisions for plants' cold hardiness. The higher #'s = hotter climates. Most Japanese Maples are hardy in zones 5 to 8; some delicate ones are hardy only to zone 6; some thrive in zone 4. In warmer areas Japanese maples like protection from afternoon sun, and, late in the season, may develop some leaf tip burn, especially while establishing themselves in new locations.
MINIATURE: Grows less than 3' a year; Matures at less than 2-3'.
DWARF: Grows 3 to 6' a year; Matures at 3-6'.
INTERMEDIATE: Grows 6-12' a year; Matures at 6-15'.
LARGE: Grows over a foot a year; Matures at more than 15'.
A word about height classifications: Mature height is at 10-15 years; All will continue to grow beyond that.
What zone am I in?
Light: Finally, we describe the lighting conditions under which these trees will perform well. It should be noted that the red trees need 6 to 8 hours of sun to best maintain their color and that some variegated trees such as 'filigree' will lose their delicate variegations in full sun.
Sizes and Prices: We list our trees as #1s and #2s. This is because of the great variations in the growth habits of the various cultivars. Some trees only grow to a couple of feet in height and others achieve a few meters. Some grow rapidly; others take their time. Some grow quickly when they are very young; others grow rapidly after a couple of years. Additionally, these are grafted plants. Some of the grafts are done only a couple inches from the ground and others are done on a taller stock so that the newly grafted tree is already several inches high. For these reasons, listing the trees by size is impractical and deceptively informative. Instead we list them as #1 and #2. #1 trees are one year grafts and #2 trees are at least a year older. Actual height varies with the individual characteristics of the various cultivars. The #1s are at least a year old. Some of them are older than this. The #2s of a specific cultivar are all at least one year older than the #1s. They are all at least 2 years old, but many are older than this.