Acer rubrum L.

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Credits

Dan Crowley (2024)

Recommended citation
Crowley, D. (2024), 'Acer rubrum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/acer/acer-rubrum/). Accessed 2024-06-16.

Genus

Common Names

  • Red Maple
  • Swamp Maple

Synonyms

  • Rufacer carolinianum (Walter) Small
  • Rufacer drummondii (Hook. & Arn. ex Nutt.) Small

Other taxa in genus

Glossary

cordate
Heart-shaped (i.e. with two equal lobes at the base).
cuneate
Wedge-shaped.
dbh
Diameter (of trunk) at breast height. Breast height is defined as 4.5 feet (1.37 m) above the ground.
hybrid
Plant originating from the cross-fertilisation of genetically distinct individuals (e.g. two species or two subspecies).
variety
(var.) Taxonomic rank (varietas) grouping variants of a species with relatively minor differentiation in a few characters but occurring as recognisable populations. Often loosely used for rare minor variants more usefully ranked as forms.

Credits

Dan Crowley (2024)

Recommended citation
Crowley, D. (2024), 'Acer rubrum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/acer/acer-rubrum/). Accessed 2024-06-16.

A deciduous tree typically to 30 m. Bark grey, smooth when young, turning darker and fissuring longitudinally with age, sometimes developing ridges or plates. Branchlets slender, glabrous or white tomentose, greenish, turning red to reddish brown. Buds ovoid, with four to seven pairs of imbricate scales. Leaves broadly pentagonal in outline, chartaceous to coriaceous, base cordate to cuneate to rounded, unlobed or three to five (-nine) lobed, 5–18 × 2–10 cm, lobes apically acute, margins serrate or double serrate with acute teeth, upper surface light green, lower surface paler or glaucous, glabrous, pubescent or white tomentose; petiole 5–10 cm long, red or green, glabrous, pubescent or white tomentose, often grooved, broadest at base; autumn colours yellow to scarlet. Inflorescence axillary, fasciculate-umbellate, few flowered. Flowers red (rarely yellow), 5-merous, monoecious or dioecious, pedicels long and slender, sepals oblong, obtuse, petals linear to oblong, shorter than sepals, stamens five to eight, inserted in the middle or on outside of the nectar disc. Samaras 1.2–3 cm long (to 5 cm in var. drummondii), wings spreading erectly to acutely. Nutlets slightly convex. Flowering December to May, before unfolding leaves, fruiting in late spring to summer. (Sargent 1965; van Gelderen et al. 1994; Rushforth 1999; Lance 2004; Weakley 2012).

Distribution  Canada New Brunswick, Ontario, Québec United States Arkansas, Alabama, Connecticut, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Missouri, Mississippi, North Carolina, New Hampshire, New York, Oklahoma, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin

Habitat Mixed deciduous forest and margins of boreal forests. It occurs on both dry and wet sites, along rivers and lakes, in marshes, swamps as well as on sandy plains, dunes and rocky, mountain slopes between 0 and 1370 m asl.

USDA Hardiness Zone 4-10

RHS Hardiness Rating H6

Awards Award of Merit

Conservation status Least concern (LC)

Taxonomic note Weakley (2012) treats Acer rubrum var. drummondii at nothospecific rank, indicating that it is of hybrid origin derived from A. rubrum and A. saccharinum, though this interpretation is not widely accepted and its varietal status is followed here. This author also treats two varieties within A. rubrum: var. rubrum and var. trilobum. The two are separated by degrees of leaf size and lobing, the nominate variety with leaves usually with cordate bases, five lobes and 7–18 cm wide, while those of var. trilobum usually have cuneate to subcordate bases, are unlobed to three lobed and 2–10 cm wide. However, intermediate leaf characters are found on plants in cultivation and therefore they are not recognised here.

At its best, Acer rubrum ranks among the finest large maples for autumn colour, and in its native eastern United States is considered ‘second in splendor [sic] only to the sugar maple’ (Peattie 2013). Now a common tree throughout its native range, before European settlement it was considered only a minor component of eastern forests, where it was found mainly in poorly drained areas (Abrams 1998). However, changes in land use and management, and the impact of pests and diseases on other trees, combined with its adaptability and ‘super-generalist’ characteristics have seen its frequency in forests greatly increased, with the species now abundant in upland areas as well as moist lowlands (Abrams 1998). A quick coloniser that reaches sexual maturity at between four and ten years old, A. rubrum can function both as an early- and late-successional species. Ostrowsky & Ashton (2022) attribute its relatively recent success to its ability to reproduce from sprouts as well as seeds: seed-origin trees are slow-growing, late-successional and shade tolerant; sprout-origin trees are fast-growing, early-successional and intolerant of shade. The species is recognised as the most common tree in the United States (Nix 2022).

Acer rubrum’s adaptability has made it popular in horticulture and it enjoys broad use in the urban environment, particularly in its native North America. Following the near-total loss of elms and concerns about the invasiveness of Norway Maple A. platanoides, A. rubrum has become the most popular street tree across the United States (Dirr & Warren 2019). Its tolerance of wet and compacted soils as well as of heat, drought (to a degree) and being easy to transplant have rendered the species a convenient choice, with forms to suit different conditions developed from numerous parts of its extensive range. Relatively free from pests, and seemingly largely unaffected by the topical Emerald Ash Borer (Iowa State University 2024), the species does however struggle in highly alkaline soils, which induce manganese deficiency causing the leaves become chlorotic (Sternberg 2004; Dirr & Warren 2019), though some cultivars are tolerant of higher soil pH (Dirr & Warren 2019). However, not all selections are available across our area, with many restricted to North America. A. rubrum is fast growing, but not as quick as the closely related A. saccharinum or their hybrid A. × freemanii. It is however less prone to storm damage than some A. saccharinum (see account of that species for further information), though is quick to decline once damaged (Sternberg 2004).

While its leaves often turn red in autumn, both the common name and epithet rubrum refer to the red flowers, produced before the leaves in late winter or early spring. Though individual plants are typically either male or female, variation has been observed among wild plants, with apparent males producing female flowers (though usually without subsequent fruit development) and vice versa (Primack 2004; Sternberg 2004). Sex change has been reported in response to stress (Sternberg 2004), as is apparent in some other maple species (e.g A. pennsylvanicum (Primack 2004)).

One of eight maples described by Linnaeus in 1753, Acer rubrum was known in cultivation even earlier than this, introduced to Britain by John Tradescant the Younger from one of his visits to Virginia prior to 1656, when it appeared in a list of plants in his collection (Leith-Ross 2006). A tree planted at Fulham Palace was measured at more than a metre in diameter in 1793, though had been lost by 1809 (Harris 1991). The current UK and Irish Champion for diameter grows at Alton, Hampshire and measures 1.26 m across, below its forking stems at 0.9 m (The Tree Register 2023). The current tallest UK tree grows at Borden Wood House, West Sussex, and is 27 m tall (The Tree Register 2023). In Belgium, it has exceeded 30 m, including examples at Arboretum Groenendaal (32 m in 2011) and Arboretum Tervuren (30 m in 2021) (Monumental Trees 2024). The tallest recorded individual appears to be an exceptional example, assumed since lost, of 53.7 m tall and 1.8 m dbh in St Clair County, Michigan (Sternberg 2004).

Among cultivated maples, Acer rubrum may be confused with its Japanese counterpart, A. pycnanthum. While the leaves of both are variable, those of A. pycnanthum tend to be more shallowly lobed, and the tree itself is usually smaller and slower growing. A. rubrum may also be confused with A. × freemanii and A. saccharinum. Features used to distinguish these three taxa are provided in the account of A. × freemanii.

Numerous selections of Acer rubrum have been made, with many available in Europe as well as North America. The not so aptly named ‘October Glory’ has become a popular choice offered for UK landscapes, while ‘Schlesingeri’ is noted for its early colour on both sides of the Atlantic. ‘Frank Jr’ has reportedly become one of the most popular forms in the United States, and is also favoured for use on limestone soils in China (Dirr & Warren 2019). The species has become increasingly used there since its introduction in 2000 (Lu et al. 2020), as evidenced by the several selections that have also been made there.


'Ablaze'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection introduced by Sarcoxie Nursery, Missouri, in 1974 (Jacobson 1996). It has a rounded crown and develops brilliant red autumn colour later than is typical for the species (van Gelderen et al. 1994). It was reported not to be available in Europe in 1994 (van Gelderen et al. 1994), which appears still to be the case.


'Autumn Flame'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Introduced in 1964–65 by A. McGill & Son nursery, Oregon, ‘Autumn Flame’ initially develops a narrow and upright crown, becoming more rounded with age, its ultimate dimensions still smaller than many other selections (Dirr & Warren 2019). Turning a reliable red and noted as one of the earliest Red Maple cultivars to turn (Jacobson 1996; Justice, in prep.), an Alabama study showed that perceived early colour was rather a more rapid transition from its summer green to autumn red (Jacobson 1996). With smaller leaves than typical, it is adapted to both heat and cold (Dirr & Warren 2019), though reportedly not fully hardy in the American Midwest (Hatch 2021–2022). A male clone (Jacobson 1996; Dirr & Warren 2019), it is present in Europe as well as North America (van Gelderen, de Jong & Oterdoom 1994).


'Autumn Glory'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

Selected by M.W. Staples, of Kent, Ohio (van Gelderen, de Jong & Oterdoom 1994; Jacobson 1996). Grown in both North America and Europe, it develops a spreading crown with orange and red autumn colour (van Gelderen, de Jong & Oterdoom 1994; Jacobson 1996).


'Autumn Radiance'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A form of moderate growth and good, early, red autumn colour (Dirr & Warren 2019). Its origins are described only as ‘pre-1990’ by Jacobson (1996).


'Autumn Spire'

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A male clone raised by H.M. Pellets from seed collected near Grand Rapids, Minnesota (Jacobson 1996), introduced in 1990 by Bailey Nurseries of the same state after twelve years of evaluation at the University of Minnesota (van Gelderen et al. 1994; Jacobson 1996). Developing an oval form, it is reported by Dirr and Warren (2019) to be the earliest commercial cultivar to colour in autumn, turning a good red. A slower grower, on account of being early to shut down in autumn, it is most useful in colder climates (Dirr & Warren 2019).


'Bailcraig'

Synonyms / alternative names
Acer rubrum SCARLET JEWELL™

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

This selection has an upright pyramidal form in youth but becomes broadly oval with age (Dirr & Warren 2019). Selected from Minnesota, it is faster growing than others from the region (e.g. ‘Autumn Spire’), though its autumn colour is average and shortlived (Dirr & Warren 2019).


'Bowhall'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A columnar clone renowned for its vibrant autumn colours, though somewhat particular in its requirements and not suited to urban soils (Dirr & Warren 2019). It was selected around 1946 by Scanlon Nursery, Ohio (Jacobson 1996), and named for the Cleveland road on which the original tree was growing (van Gelderen et al. 1994). Female, and thus a fruiting tree, its leaves turn yellow, orange, red or purple in autumn (Jacobson 1996; Justice, in prep.). ‘Scanlon’, with which ‘Bowhall’ is much confused, is derived from a sport from this tree (Jacobson 1996).


'Brandywine'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection made at the US National Arboretum, from a cross between ‘October Glory’ and Autumn Flame’ (Hatch 2021–2022). Male, it develops a pyramidal form, turning red and purple in autumn, later than many other cultivars (Dirr & Warren 2019; Schmidt & Son Co. 2023). ‘Brandywine’ also been noted to have shown good adaptability to the heat of the southern United States (Hatch 2021–2022; Schmidt & Son Co. 2023). It is widely grown in Europe as well as in North America (Edwards & Marshall 2019).


'Candy Ice'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A pink, white and green-leaved tree that scorches if grown in full sun (Mendocino Maples 2024). Described as a ‘semi dwarf’ by Hatch (2021–2022), the foliage turns yellow and orange in early autumn (Mendocino Maples 2024).


'Columnar Walters'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Selected by Richard Walters of Maplewood, New Jersey, and available by 1958 from Princeton Nursery of the same state (Jacobson 1996). Fast-growing, it has an upright form and good autumn colour, though the leaves are quick to drop (Jacobson 1996).


'Columnare'

Synonyms / alternative names
Acer rubrum 'Pyramidale'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4a

An old cultivar, included by Bean (1976), who noted a tree that was featured in the 1894 edition of Garden and Forest (p.65, as A. saccharum), which grew on private land in Flushing, New York, then 25 m tall. Introduced by Parsons Nursery of Flushing, New York (Jacobson 1996), it has an upright form that is narrower than ‘Bowhall’ or ‘Scanlon’ (Justice, in prep.). Its leaves turn orange to deep red in autumn (Dirr & Warren 2019; Justice, in prep.). A tree at the Sir Harold Hillier Gardens, Hampshire, UK was recorded as 22 m tall in 2013 (Edwards & Marshall 2019).


'Cumberland'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A compact, globose clone, selected at the US National Arboretum in 1986 from a batch of open pollinated seedlings from material gathered in Norris, Tennessee (Hatch 2021–2022). It has red autumn colour (Hatch 2021–2022).


'Curtis'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

An upright, female clone with reddish new growth and red autumn colour (Hatch 2021–2022). It was introduced in 1949 by Vallou Curtis of Curtis Nusery, Callicoon, New York (Jacobson 1996).


'Davey'

Synonyms / alternative names
Acer rubrum DAVEY RED™

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A selection made by the Davey Tree Expert company, Ohio, that has been in circulation since the 1980s (Jacobson 1996). It is a slow growing, compact tree with small leaves that turn yellow to dark orange or red in autumn (Jacobson 1996). It is female, and noted as being hardier than most (Jacobson 1996).


'Doric'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Selected around 1960 by Scanlon Nursery, Ohio, and introduced in 1964 (Jacobson 1996), it makes a columnar tree, with glossy foliage that colours well in autumn (van Gelderen et al. 1994). It is grown in Europe as well as in North America (van Gelderen et al. 1994).


'Drake'

Synonyms / alternative names
Acer rubrum 'V.J. Drake'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection named after Virgil James Drake of County Line Nursery, Hartford, Michigan and introduced by Schmidt Nursery, Oregon (Jacobson 1996). It is noted for its prolonged autumn colour, turning from green to violet then red and yellow (Jacobson 1996).


'Excelsior'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection with broad, pyramidal form, introduced in 1979–80 by Handy Nursery, Oregon (Jacobson 1996). It turns orange to red in autumn (Jacobson 1996).


'Fairview Flame'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Thought to be from the nursery of A. McGill & Son, Oregon, described in its 1991–92 catalogue (Jacobson 1996). A vigorous male clone, it has orange to deep red autumn colour (Jacobson 1996; Dirr & Warren 2019).


'Firzam'

Synonyms / alternative names
Acer rubrum FIREBALL™

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A selection made by Lake County Nursery, Ohio, advertised as a ‘narrower, more pyramidal’ and ‘very hardy’ form of Acer rubrum (Lake County Nursery 2019).


'Frank Jr'

Synonyms / alternative names
Acer rubrum REDPOINTE™

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A J.F. Schmidt Nursery introduction in circulation largely as an Acer rubrum selection, though with characters of A. saccharinum and thus of somewhat disputed parentage. Though its consistent, early scarlet autumn colour suggests A. rubrum, the coarsely serrated, prominently lobed leaves indicate that A. saccharinum is likely in its parentage (Justice, in prep.). It is included here following Dirr & Warren (2019), consistent with placement in nursery catalogues. A popular seller at J.F. Schmidt Nursery, it has a pyramidal form with good branch structure and good vigour (Dirr & Warren 2019). Unlike many related selections, it reportedly does well in more alkaline soils, exhibiting more resistance to leaf chlorosis than other forms (Schmidt & Son Co. 2023). It is apparently sought after for planting on limestone in China (Dirr & Warren 2019), and is becoming popular in Europe.


'Franksred'

Synonyms / alternative names
Acer rubrum RED SUNSET™

Awards
Award of Garden Merit

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection dating from the 1940s, introduced in 1966 by J.F. Schmidt Nursery (Jacobson 1996). Reportedly the most commonly planted A. rubrum in North America during the 1970s and 80s (Jacobson 1996), it continues to be recommended particularly for the northern United States (Dirr & Warren 2019), where it provides long-lasting autumn colours in orange to red shades (Jacobson 1996). In southern states, its popularity has been superseded by ‘October Glory’ (Dirr & Warren 2019). Also grown in Europe, it is a female that develops a broad, oval crown (Jacobson 1996). Its name was was inspired by the 1960 song title Red sails in the Sunset (Jacobson 1996).


'Gerling'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Selected around 1950 by Scanlon Nursery, Ohio, and introduced in 1955–56, having been named for dendrologist Jake Gerling of Rochester, New York (Jacobson 1996). It has a broadly pyramidal habit, turning yellow to red in autumn (Jacobson 1996). This male clone is grown in Europe as well as North America (van Gelderen et al. 1994).


'Green Pillar'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection made for its compact, fastigiate to narrowly columnar habit (Hatch 2021–2022).


'Halka'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A fast growing clone, ultimately becoming a large tree with a rounded crown whose leaves turn yellow in autumn (Dirr & Warren 2019).


'HOSR'

Synonyms / alternative names
Acer rubrum SUMMER RED®

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

Originating in South Carolina and selected for its deep red new growth (Dirr & Warren 2019), it is now grown in Europe as well as North America (Edwards & Marshall 2019). Suited to warmer climates, it develops a broad oval crown, its leaves turning yellow to orange in autumn (Dirr & Warren 2019).


'Jamestown'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Selected by T.D. Watkins III of Powhaten, Virginia, in 1993, as a sport of ‘Autumn Flame’ (Hatch 2021–2022). Faster growing than most selections, its leaves turn red in autumn (Hatch 2021–2022).


'Jinmaihong'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A Chinese selection with long-lived autumn colour, reportedly best in early November (Hatch 2021–2022).


'Jinse Qiutian'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Another Chinese selection that, like ‘Jinmaihong’, reportedly offers long-lasting autumn colour, turning golden brown (Hatch 2021–2022).


'Joseph'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

A clone introduced by Vivai Sartori of Erba, Italy (Edwards & Marshall 2019). It is slow-growing, with an upright habit and yellow to red autumn colour (Edwards & Marshall 2019).


'Karpick'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

A selection introduced before 1982 by Schichtel Nursery, New York, having been named for Frank E. Karpick, a former forester from Buffalo (Jacobson 1996). Its form is narrow, with a dense crown, broadening with age (Jacobson 1996; Dirr & Warren 2019). Male, its autumn colour range is yellow, orange and red (Jacobson 1996). It is noted as being favoured for streets and other amenity plantings in the UK (Edwards & Marshall 2019).


'Katie Cole'

Synonyms / alternative names
Acer rubrum SUMMER SENSATION®

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Found growing among plants of ‘Franksred’ at Sunleaf Nursery, Madison, Ohio, it was selected for its vibrant red new growth (Hatch 2021–2022).


'Landsburg'

Synonyms / alternative names
Acer rubrum FIREDANCE®

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

Discovered by Roger B. Landsburg in northern Minnesota and introduced by Bailey Nurseries in 1988, it develops an oval crown, with brilliant red autumn colour (Jacobson 1996). Though often listed under this species, it is also speculated to belong to A. × freemanii (Jacobson 1996).


'Magnificent Magenta'

Synonyms / alternative names
Acer rubrum BURGUNDY BELLE®

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A selection introduced by Heritage Trees of Jacksonville, Illinois (Hatch 2021–2022), the original tree came from Kansas (Dirr & Warren 2019). It has smaller leaves and later colour than is typical for Acer rubrum, and it tolerates less moisture and higher pH soils than most (Dirr & Warren 2019). The foliage flushes red, turning dark green then a lasting deep red in autumn (Schmidt & Son Co. 2023).


'Northwood'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 3

Found by L. Snyder as a seedling near Floodwood, Minnesota and introduced by Bailey Nurseries (Hatch 2021–2022). One of the first Minnesota selections, it is still considered one of the best by Dirr & Warren (2019). Fast-growing (faster than ‘Autumn Spire’), it develops a rounded crown to around 15 m tall (Edwards & Marshall 2019). A male clone, its leaves turn orange in autumn, though it doesn’t do well on alkaline soils nor in hot, dry areas (Hatch 2021–2022). ‘Northwood’ was introduced to the UK in around 1980 (Edwards & Marshall 2019).


'October Brilliance'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A little-grown cultivar of unknown origin dating from before 1982 (Jacobson 1996). It develops a tight crown, with foliage emerging later than typical Acer rubrum, with red to orange autumn colour (Jacobson 1996).


'October Glory'

Synonyms / alternative names
Acer rubrum 'PNI 0268’

Awards
Award of Merit; Award of Garden Merit

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

Introduced by Princeton Nursery, New Jersey, in 1961–62 (Jacobson 1996), ‘October Glory’ has become one of the most widely-grown Acer rubrum selections on both sides of the Atlantic. Female (Jacobson 1996), it is noted for being somewhat late to colour; ‘November Glory’ might have been a more apt name (e.g. Dirr & Warren 2019). Dependable though, it turns a good scarlet and develops a rounded crown.


'Oktoberfest'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Introduced c. 1991–92 by Moller Nursery of Gresham, Oregon, its leaves turn deep red in autumn (Jacobson 1996).


'Olson'

Synonyms / alternative names
Acer rubrum NORTHFIRE®
Acer rubrum 'Olsen'

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A notably hardy clone from Brainerd, Minnesota and introduced around 1990 by Bailey Nurseries (Hatch 2021–2022). It has a broadly oval to rounded habit, with vigorous growth and is somewhat open when young (Hatch 2021–2022). A female, its leaves turn yellow, orange and red in autumn (Dirr & Warren 2019).


'Phipps Farm'

Synonyms / alternative names
Acer rubrum 'Weston'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Introduced by Weston Nursery, Massachusetts around 1973 and named for their Phipps Farm Nursery (Jacobson 1996). Broadly pyramidal to rounded in habit, it is noted for its long lasting yellow to red autumn colours (Jacobson 1996; Hatch 2021–2022). It was reported as rare, possibly lost by Jacobson (1996), though plants may still exist in gardens.


'Polara'

Synonyms / alternative names
Acer rubrum RUBYFROST™

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

Introduced in the 1990s by Chicagoland Grows® inc. (Jacobson 1996) from a seedling selected by Wood River Nursery, Wisconsin (Hatch 2021–2022). It is notably hardy, drought tolerant and has a strong branching structure (Jacobson 1996).


'Red King'

Synonyms / alternative names
'Effegi'

RHS Hardiness Rating: H7

USDA Hardiness Zone: 4

An upright cutivar of Italian origin, introduced by Fratelli Gilardelli in 1988 (van Gelderen & van Gelderen 1999). Autumn colour is reported to be a good crimson to orange red (van Gelderen & van Gelderen 1999).


'Red Rocket'

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A columnar form that retains its shape into maturity, introduced by the United States National Arboretum (Hatch 2021–2022), from Minnesota-sourced material (Dirr & Warren 2019). It makes for a good choice for narrow streets, and has a slower growth rate than other columnar clones (Dirr & Warren 2019). Its leaves turn orange and red in autumn (Schmidt & Son Co. 2023).


'Red Skin'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Introduced by Schichtel Nursery of Orchard Park, New York (Jacobson 1996). It has a rounded form (Jacobson 1996), with dark red autumn colour that appears earlier than typical for the species (Hatch 2021–2022).


'Red Super Sonic'

Common Names
Super Sonic™ Red Maple

Synonyms / alternative names
Acer rubrum SUPER SONIC™

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A narrow, upright tree suited to small spaces (Sooner Plant Farm 2024). It has orange and red autumn colour and is considered by Sooner Plant Farm, who introduced it, to be an improvement on ‘Red Rocket’ (Sooner Plant Farm 2024).


'Sanguineum'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

One of the first named selections of the species (Hatch 2021–2022), suspected no longer to be in cultivation by van Gelderen et al. (1994). The original grew at the Jardin des Plantes, Paris (Bean 1976), with flowers vibrant red and leaves glaucous green beneath and somewhat more pubescent than in the type (Bean 1976). It may have belonged to var. drummondii.


'Scanlon'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Treated as synonymous with ‘Bowhall’ by Dirr & Warren (2019), and often confused with that selection. Though derived from a branch sport of ‘Bowhall’, ‘Scanlon’ develops a denser, more uniform crown and is more prone to fasciated branching (Justice, in prep.). It is a fruiting clone (as is ‘Bowhall’), and colours well in autumn in shades of orange red and purple (Justice, in prep.).


'Schlesingeri'

Synonyms / alternative names
Acer rubrum 'Schlesinger'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A clone selected in the United States for its brilliant, and early autumn colour. Dosmann (2009) described ‘Schlesingeri’ as ‘autumn’s harbinger’, with tints observed in August and the entire tree in full colour from early September, usually holding into October.

‘Schlesingeri’ was found by Professor Sargent in his neighbour’s grounds in Brookline, Massachusetts – a Mr Barthold Schlesinger – from which material was accessioned at the Arnold Arboretum in 1888, and a tree subsequently planted on Meadow Road, though this was in decline by 2009 (Dosmann 2009). Reputed to be the oldest Acer rubrum selection (Dirr & Warren 2019), it was first put into commerce in Europe, rather than in the United States, by Späth’s nurseries, who listed it in their 1896–1897 catalogue (Dosmann 2009). Material was again distributed to nurseries in 1951, from whence its availability in North America increased (Dosmann 2009), though in more recent years plants sold under the name have proved not to be true ‘Schlesingeri’, including plants accessioned at the Arnold and since removed (Dosmann 2009). Repropagation has enabled the original tree to be replaced and further material distributed to nurseries, so that authentic ‘Schlesingeri’ may be found in nurseries again (Dosmann 2009). However, the cultivar has become less popular than it once was in the United States having been superseded by more recent selections (Hatch 2021–2022).


'Schocking Gold'

RHS Hardiness Rating: H7

USDA Hardiness Zone: 3

A selection with golden spring and summer foliage. It was discovered by North Carolinian plantsman Richard Schock in Boonville, North Carolina, and subsequently shared with Plant Delights Nursery in 1993, who named the selection after its discoverer (Plant Delights Nursery Inc. 2018). Of upright stature in youth, its leaves turns yellow, orange and red in autumn (Broken Arrow Nursery 2022). It is sometimes listed under the erroneous name ‘Shocking Gold’, but the play on the name of its discoverer is correct.


'Shade King'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A male clone introduced by Handy Nursery, Oregon in around 1973 (Hatch 2021–2022). It has an upright oval habit, with leaves that turn yellow to red in autumn (Hatch 2021–2022).


'Snow Fire'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

A variegated clone, the leaves mottled white, with pinkish new growth (Hatch 2021–2022).


'Somerset'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

The result of a cross between ‘October Glory’ and ‘Autumn Flame’ made at the US National Arboretum in 1982; it became commercially available in 1994 (Hatch 2021–2022). It has a pyramidal habit and good branch structure, with leaves turning red in autumn (Dirr & Warren 2019). It was bred for resistance to potato leaf hopper as well as improved autumn colour (Edwards & Marshall 2019), and is now grown in Europe as well as in North America.


'Sun Valley'

Common Names
Sun Valley Maple

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5b

A male clone resulting from a cross between ‘Franksred’ and ‘Autumn Flame’ made at the US National Arboretum (Schmidt & Son Co. 2023). Slow growing, with ultimate dimensions smaller than most Acer rubrum, it develops a uniform, oval crown (Schmidt & Son Co. 2023; Dirr & Warren 2019). Autumn colour is orange to red, and stronger in northern states than further south in the United States (Dirr & Warren 2019).


'Territorial'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

A small-leaved selection introduced by T.H. Belcher Nursery of Boring, Oregon around 1991 (Hatch 2021–2022). It has a rounded habit and red autumn colour (Hatch 2021–2022).


'Tilford'

Synonyms / alternative names
Acer rubrum 'Paul E. Tilford'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 4

Selected around 1949 by Scanlon nursery, Ohio, and named two years later for plant pathologist Dr. Paul E. Tilford of Wooster, Ohio (Jacobson 1996). It makes a large tree with a pyramidal or rounded crown, requiring ample space for good development (van Gelderen et al. 1994). Grown in Europe and North America, it is recommended for coastal areas in Europe alongside ‘October Glory’ (van Gelderen et al. 1994).


var. drummondii (Hook. & Arn.) Sarg.

Common Names
Swamp Red Maple

Synonyms
Acer drummondii Hook & Arn
Acer drummondii 'Woolly'

Var. drummondii has has white tomentose branchlets (at least at first), petioles, and leaf undersides, Its flowers and fruits are deep red, the winged samaras 2.7–5 cm long (Sargent 1965; Bean 1976; Weakley 2012).

Distribution

  • United States – Alabama, Arkansas, Delaware, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maryland, Missouri, North Carolina, New Jersey, South Carolina, Oklahoma, Tennessee, Texas, Virginia

RHS Hardiness Rating: H4

USDA Hardiness Zone: 5

Not to be confused with the widely-grown Acer platanoides cultivar ‘Drummondii’, planted individuals of this Acer rubrum variety are far less frequently encountered than those of the type, including its great many horticultural selections. There are a small number of cultivars that are attributed to this variety, as indicated by their inclusion here.


'WW Warren'

Synonyms / alternative names
Acer rubrum RED SENTINEL™

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

Of fastigiate form with strong red autumn colour, well suited to streets and other restricted spaces (Schmidt & Son Co. 2023).


'Yanhong'

RHS Hardiness Rating: H6

USDA Hardiness Zone: 5

A Chinese selection reportedly with long-lasting, bright red, autumn colour (Hatch 2021–2022).