Wednesday, January 12, 2011

Acer shirasawanum

Acer shirasawanum is one of my favorite maples. Although I love the lacy and delicate leaves on some of the Japanese Maples, there is something about these wide leaves that I find attractive. The species (above) has leaves that are a light green, maybe almost chartreuse. Very, very old trees might get to be 50 feet tall, but this is rare in cultivated trees. My tallest one, planted 15 or 18 years ago, is barely more than 12 feet tall. It is native to central and southern Honshu and Shikoku in Japan.
The photo below is Acer shirasawanum aureum. It may sometimes be found with the name 'Ogon', which just means yellow. The spring foliage is pale yellow green and as the season progresses, it tends to green up a little, though it holds its color better in shade. Its fall colors are spectacular ranging from yellow through orange and red with even some purples showing up on some leaves. It is an extremely slow growing tree
Acer shirasawanum 'Autumn Moon' is a medium sized tree with unusual colored foliage. The color can be pink to orangey red. More sun gives better colors. The original plant was a seedling off of 'Aureum'. Fall color is just an intense version - very intense - of the regular color.

Acer shirasawanum ezono momiji . I've also seen this listed as an Acer japonicum, but I'll go with the shirasawanum since the leaves are much more like one of those with the 9-11 lobes and the indentations between the lobes, not all that far divided. Originally the shirasawanums were included as a subgroup in the japonicums, so maybe that's where the confusion comes in. Although it is pretty much just green most of the year, the fall color blends reds and oranges and yellows.

Acer shirasawanum palmatifolium is about the same color of the species, but with much more divided leaves, looking more like one of the Japanese maples. It can take a bit more sun than the others ...
... and the fall colors are just wonderful.

These all grow in zones 5-9, like full sun to light shade (more shade in hotter climates). It doesn't like windy spots, so a bit of protection is appreciated. It likes moist but well-drained soil. Ours don't seem to have insect or disease problems, but you might be troubled by scale insects, caterpillars, aphids or leaf spot if those things are a problem in your garden.
Now on the the true japanese maples. These will take a few days because we grow so many of them.

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