Red Leaf Full Moon Maple

‘Ruby’ is an upright Japanese fullmoon maple with a striking red-to-green-to-autumn color sequence. New leaves emerge deep red to nearly black, mature to green with reddish tones, and turn orange, red, and purple in fall, making this a foliage-focused specimen for a sheltered garden. ## Foliage and form The rounded leaves have 7–11 pointed lobes, and young stems are red. The strongest color begins as leaves unfurl in early spring, shifting from black-red to bright red. Summer foliage becomes greener, often with bronzy tones and red edges. In fall, orange, red, and purple replace the summer canopy. Small red-purple flowers appear in early spring, followed by paired winged seeds typical of fullmoon maples. Published sizes vary by age and reference. Wilson Bros Gardens estimates 15–20 feet tall and 10–12 feet wide at maturity, while Conifer Kingdom lists about 10 by 5 feet at 10 years. The Dawes Arboretum describes its specimen as a medium tree believed to reach about 20 feet in both directions. Treat the 10-year dimensions as an early size guide and allow room for a larger mature crown. ## Placement and growing conditions Plant ‘Ruby’ where its changing foliage can be seen, such as a courtyard, small lawn, woodland edge, or as an understory specimen. It can grow in full sun or partial shade, but dappled shade or protection from hot afternoon sun is prudent in hot-summer climates. Provide moist, well-drained soil and shelter from drying wind. Nursery hardiness guidance ranges from USDA zones 5–8 in hotter summers to zone 9 in cool or mild-summer sites; a broad zone number alone does not guarantee success in arid heat. ## Cultivar identity and sourcing The Dawes Arboretum maintains an accession of *Acer japonicum* ‘Ruby’ and records it as a deciduous specimen tree with red spring foliage. Current specialty-nursery references include [Conifer Kingdom](https://www.coniferkingdom.com/acer-japonicum-ruby) and [Wilson Bros Gardens](https://www.wilsonbrosgardens.com/acer-japonicum-ruby-full-moon-japanese-maple-3g.html). The sources reviewed do not identify an original breeder, a branded series, or a cultivar-specific patent number. The [USPTO Patent Public Search](https://www.uspto.gov/patents/search/patent-public-search) is the official U.S. source for checking patent records. ## Sources - [The Dawes Arboretum: Ruby fullmoon maple](https://dawesarb.arboretumexplorer.org/taxon-19340.aspx) - [Conifer Kingdom: Acer japonicum ‘Ruby’](https://www.coniferkingdom.com/acer-japonicum-ruby) - [Wilson Bros Gardens: Ruby Full Moon Japanese Maple](https://www.wilsonbrosgardens.com/acer-japonicum-ruby-full-moon-japanese-maple-3g.html) - [NC State Extension: Fullmoon maple](https://plants.ces.ncsu.edu/plants/acer-japonicum/common-name/fullmoon-maple/) - [Royal Horticultural Society: Acer japonicum](https://www.rhs.org.uk/plants/22273/acer-japonicum/details) - [Oregon State University: Acer japonicum](https://landscapeplants.oregonstate.edu/plants/acer-japonicum) ## Maintenance Keep the soil evenly moist while the tree establishes and during extended dry periods, while maintaining good drainage. Mulch around the root area but keep it clear of the trunk. The RHS recommends pruning Japanese maples only if needed, from late autumn to midwinter; otherwise, let the upright branching structure develop naturally.