The maples belong to the genus Acer, an important group of mainly deciduous trees and shrubs in the family Sapindaceae, which are widely cultivated throughout the temperate northern hemisphere. Some, such as Acer griseum, have ornamental bark; but most are valued in cultivation for their brilliant autumn foliage in shades of yellow, orange and red. A vast number of cultivars have been developed for garden use. The palmate maple Acer palmatum alone has thousands of cultivars, many of which originate in Japan where the plant is especially prized for its compact size and elegant domed shape. Many maple species lend themselves to bonsai treatment. ^[1]

All tolerate a range of growing conditions, but prefer a partially shaded, sheltered position in soil that is well-drained but also retains moisture. Most are reasonably hardy down to −20 °C (−4 °F) or so. The following is a selected list of cultivars which in the UK have gained the Royal Horticultural Society’s Award of Garden Merit (confirmed 2018). ^[2]

Species	Cultivar name	Year	Ref	Autumn colour	Height	Spread	Image
A. campestre		1993	[3]	yellow/red	12m	8m
A. cappadocicum	‘Aureum’	1993	[4]	yellow	12m	8m
A. cappadocicum	‘Rubrum’	1993	[5]	yellow	12m	8m
A. davidii	‘George Forrest’	1993	[6]	yellow	12m	8m
A. × freemanii	Autumn Blaze=‘Jeffersred’	2012	[7]	orange/red	12m	8m
A. griseum		1993	[8]	orange/red	12m	8m
A. japonicum	‘Aconitifolium’	1993	[9]	red	8m	8m
A. japonicum	‘Vitifolium’	1993	[10]	red	8m	8m
A. micranthum		2012	[11]	orange	8m	4m
A. negundo	‘Winter Lightning’	2012	[12]	yellow	10m	8m
A. negundo var. violaceum		2012	[13]	purple	12m	8m
A. palmatum	'Beni-maiko’	1993	[14]	yellow/orange/red	1.5m	1.5m
A. palmatum	'Beni-tsukasa’	1993	[15]	orange	2.5m	2.5m
A. palmatum	'Bloodgood’	1993	[16]	red	4m	4m
A. palmatum	'Burgundy Lace’	1993	[17]	purple	4m	4m
A. palmatum	'Chitose-yama’	1993	[18]	red	2.5m	2.5m
A. palmatum	'Crimson Queen’	1993	[19]	red/purple	2.5m	2.5m
A. palmatum	'Elegans’	2012	[20]	yellow/orange/red	2.5m	2.5m
A. palmatum	'Garnet’	1993	[21]	red/purple	1.5m	2.5m
A. palmatum	'Inaba-shidare’	1993	[22]	red/purple	2.5m	2.5m
A. palmatum	'Katsura’	2002	[23]	orange	4m	4m
A. palmatum	'Orange Dream’	2012	[24]	orange/yellow	4m	4m
A. palmatum	'Orangeola’	2012	[25]	orange/red	4m	2.5m
A. palmatum	'Ornatum’	2012	[26]	red	3m	1.5m
A. palmatum	'Osakazuki’	1993	[27]	red/pink	4m	4m
A. palmatum	'Red Pygmy’	1993	[28]	red/purple	1.5m	1.5m
A. palmatum	'Sango-kaku’	1993	[29]	yellow/red	6m	4m
A. palmatum	'Seiryu’	1993	[30]	yellow/orange/red	4m	4m
A. palmatum	'Shin-deshojo’	2012	[31]	red/orange	2.5m	2.5m
A. palmatum	'Shish geshira’	2012	[32]	orange	4m	2.5m
A. palmatum	'Trompenburg’	2002	[33]	orange/red	4m	4m
A. palmatum	'Villa Taranto’	2012	[34]	yellow	4m	2.5m
A. platanoides	‘Crimson King’	1993	[35]	purple/crimson	12m	8m
A. platanoides	Princeton Gold='Prigo’	2012	[36]	yellow	12m	8m
A. pseudoplatanus	'Brilliantissimum’	1993	[37]	pink/green/cream	8m	8m
A. rubrum	'October Glory’	1993	[38]	red	12m	8m
A. rubrum	Red Sunset='Franksred’	2012	[39]	red	12m	8m
A. shirasawanum	'Aureum’	1993	[40]	yellow	8m	8m
A. tegmentosum		2012	[41]	yellow	12m	8m
A. triflorum		2002	[42]	orange	12m	8m

References