Acer shirasawanum ‚Munn001‘ MOONRISE Shirasawa maple, Japanese maple

Shirasawan’s maple is a sought-after species of Japanese maple valued mostly for its unique leaf shape. To date (July 2020) there are 17 recognized varieties, and MOONRISE is a recent introduction from the USA where its inventor Carl A. Munn patented it as PP16718 in 2004. He discovered it in about 1987 as a naturally occurring mutation of Aureum variety. It had different colour, faster growth, and better resistance to sun scorch.

MOONRISE Shirasawan’s maple produces bright lime yellow-green foliage in early spring which gains scarlet red flush as they open to its typical seashell shape with 7-11 lobes. As the leaves mature, red hues disappear and pop up only on newly emerging leaves at the branch tips. An important feature is also its great tolerance to full sun – it can take all day sun, only in dry soils the top of the plant may manifest some sun scald during the hottest days of summer unless regularly watered.

It grows rather fast when young, making an upright shrub with slightly V-shaped canopy. A 17-year-old plant in the inventor’s nursery was 4m tall and 3.5m wide, and the ultimate size of a mature specimen is expected to reach about 5 by 4 meters.

All green or yellow-leaved Japanese maples do best in filtered sunlight or part shade in neglected gardens. But if you are ready to water them during hot and dry spells of the season you can grow recommended varieties in full sun, too. Red-leaved maples on the contrary NEED full sun to colour well, even the dissectum type with deeply cut foliage.

Japanese maples prefer light, acidic, well-drained soil that will retain moisture – keep them mulched at all times. If you feel you need to feed it, use balanced, slow-release fertilizers only. They can be pruned in early winter or trimmed and shaped for bonsai in early summer. Still, I assume that each Japanese maple is so beautiful only if left to its own devices without any intervention, making each one an unrepeatable original. Plants older than 3-5 years (wood maturity pending) are fully hardy to about -29°C (USDA zone 5).

Last update 21-07-2020