Japanese maple seeds

Habitat

native to Japan, China, Korea
zone 5 for many, while other selections are only reliable to zone 6 or warmer
an understory tree in its natural setting
Habit and Form

small deciduous tree 15′ to 25′
shape can be rounded to irregular
habit and form is variable since most cultivated plants are various cultivars
texture fine to medium
growth rate is slow

Summer Foliage

opposite, 2″ to 5″ long, medium green color
5, 7 or 9 lance-shaped lobes, palmately arranged
excellent quality summer foliage

Autumn Foliage

turning yellow, orange, red or purple
dependable for fall coloration
color develops late and leaves hold well

Flowers

small, red or purple, in May and June

Fruit

samaras 0.5″ to 0.75″ long
generally reddish tinged green, but some are just green

Bark

twigs have green and red, polished, shiny bark that is showy
trunk and main branch bark is gray
stem and bark color is a valuable ornamental feature

Culture

full sun to partial shade is best; shade tolerant
moist, slightly acidic, well-drained, high organic matter soil is ideal
often stated to be delicate plants, but probably more adaptable than given credit for
dislikes hot, dry locations
avoid windswept winter locations
Landscape Uses

specimen plant, especially cultivars
accent plant for artistic appearance
rock gardens
in mini-groves
avoid over use of colored foliage selections
possesses multiseason interest (summer foliage, fall foliage color, twig and bark color and quality)
Liabilities

relatively pest and maintenance free
twig kill, bark split and lack of winter hardiness can be a problem with some selections
spring frosts can damage emerging leaves
ID Features

5 to 9 palmately-lobed, dissected leaves
twig bark color of red and green
twigs glabrous; Acer japonicum twigs may be slightly pubescent with long hairs
terminal bud absent
bud bases surrounded by a hairy, papery sheath, giving the appearance of a hula skirt around the buds

Propagation

by seed
cultivars generally grafted
cultivars also by softwood stem cuttings
Cultivars/Varieties

A complete discussion of the range of Acer palmatum cultivars is beyond the scope of this forum, as hundreds exist. Listed below are some of the more common cultivars. For more detailed listings, consult a reference book or specialty catalog.

var. atropurpureum – Leaves are reddish purple when they emerge, but typically fade to green by July. Fall color is red. Less expensive to buy than red foliage cultivars that retain red foliage throughout summer.

var. dissectum – Trees have leaves that are finely cut and incised. Leaves have 7, 9 or 11 lobes. Texture is fine and leaves can appear threadlike.

‘Bloodgood’- has rosy foliage in early summer that darkens to burgundy by mid-summer. Was selected because of its excellent color retention. A relatively slow growing, upright to rounded form that reached 15′ to 20′. Very commonly grown and offered.

‘Butterfly’ – A true variegated form with gray/green leaves featuring a white/pink margin. A slow grower, only reaching 15′ with age.

‘Crimson Queen’- a red foliage form with dissected leaves and weeping or arching branching. Slow growing, ultimately reaching 8′ to 10′ tall and 12′ wide.

‘Sango Kaku’ – An upright tree reaching 25′ tall. Notable for the vivid red coloring of the young stems that make it a fine beacon in the winter landscape. The coloring is only prominent on the new growth, however, as it fades to gray with age.

‘Shaina’ and ‘Sharp’s Pygmy’ – Two common dwarf cultivars which form dense, rounded trees that seldom exceed 4′-6′ tall.

‘Versicolor’ – A strong-growing, hardy form developing into an upright tree of about 25 feet in 30 to 40 years. The leaves are deep green with varying amounts of white in streaks, blotches and flecks.

‘Viridis’- a mounded form with bright green dissected foliage. Orange-gold fall foliage.