Since their introduction to the West in the 1850s, Japanese spireas (Spiraea japonica cvs.) have been embraced by gardeners everywhere for their white, pink and red flowers, tidy habit, easy care, ability to grow in average to poor soils and, more recently, for their bright, colourful foliage. From shopping centre parking lots to the most exclusive gardens, it’s hard to avoid stumbling across at least one of the more than 50 cultivars that have been developed during the past 125 years.
As the name suggests, Spiraea japonica is native to Japan, but is also indigenous to Korea and China, with slight variations in height, habit and flower colour in each geographic region. In the wild, Japanese spireas are erect or mounding, multi-stemmed, deciduous shrubs that bear terminal corymbs (or clusters) of flowers in summer, after most other shrubs have finished blooming. In their native habitat, they grow in rich, moist soil along the edges of streams and rivers and at the edges of forests.
Modern breeding efforts have revolutionized Japanese spireas, with much of this work taking place in Quebec, as well as in the U.S. and the U.K. Their season of bloom has been increased—from late spring to early autumn (Golden Princess), their blooms have been made larger (Double Play Big Bang), non-flowering groundcover types have been developed (‘Golden Carpet’), and the palette of foliage colour has been widened and extended to include spring and autumn (Double Play Artist).
The variety of ways to use Japanese spireas in the landscape is as diverse as the plants themselves: Tall, upright cultivars (‘Anthony Waterer’ types that grow to five feet / 1.5 m) lend themselves to informal hedging or foundation plantings, or to add midsummer colour to groups of shrubs; lower-growing cultivars with colourful foliage (Limemound) or a long season of bloom (‘Flowering Choice’) work beautifully in herbaceous borders and add structure, while groundcover types (‘Golden Elf’) effortlessly light up entire sections of the garden.
Going for the gold
For years, the holy grail of Japanese spirea breeding was to develop a golden-leaved cultivar that held its colour all season long without the foliage reverting to green during the dog days of summer. This goal was more or less achieved in 1995 with the release of Magic Carpet, but a bit of a design dilemma ensued: pink flowers held above yellow leaves just aren’t to everyone’s taste, although there’s no denying that this vibrating combo definitely draws the eye, and can be useful to make a statement or create a focal point.
My personal taste is less flamboyant, so I’ve taken to planting groups of the gaudier cultivars in front of the evergreen hedge that surrounds my property. The deep green of the hedge seems to chill out the bright colours of the spireas and sets them off in a colourful but unobtrusive way. For gardeners who find the entire concept altogether too much, I recommend sticking with green foliage or non-flowering, golden-leaved groundcover types.
The first Japanese spirea to reach the West was S. j. ‘Fortunei’ (syn. S. j. var. fortunei), sent from China to England in 1849 by intrepid Scottish plant hunter Robert Fortune (1812–80). Just as it was becoming popular with the gardening public, it was superseded by another variety developed by Karl Froebel in Zürich, who had sent specimens of his new hybrid to Kew Gardens (London, U.K.) in 1885. By crossing S. japonica with S. j. var. albiflora, Froebel created a dwarf plant with golden and/or gold-splashed leaves bearing carmine-pink flowers; this form became known as the Bumald spirea (S. ×bumalda), named in honour of Bumaldus, an obscure 17th-century Italian scientist.
While the original Bumald cross proved unstable over time, it produced numerous branch sports (naturally occurring mutations) that in turn gave rise to the next wave of cultivars, many of which are still with us today. The first and most famous of these was discovered by Anthony Waterer at his Knaphill Nursery in Woking (Surrey, England) and introduced in 1890 as ‘Anthony Waterer’. Although the original plant has been lost, there are still available several carmine-red-flowered strains that bear the name.
Hardly a Stable Mabel itself, before long ‘Anthony Waterer’ produced several well-known sports, including ‘Coccinea’, ‘Crispa’ and ‘Dart’s Red’; though not closely related, other cultivars such as ‘Atrosanguinea’, ‘Crimson Glory’ and ‘Froebelii’ are virtually indistinguishable from the original Knaphill Nursery introduction. Most of these older types are still referred to in the nursery trade as S. ×bumalda cultivars, but modern taxonomists generally agree that they all belong under the wider S. japonica umbrella.
As if to further complicate matters, many Japanese spireas that were originally introduced as distinct new varieties (e.g., S. j. var. fortunei) have turned out to be cultivars, as have former species such as S. bullata (now S. j. ‘Bullata’), which had been introduced to Europe in 1864 by 19th-century Russian botanist and plant hunter extraordinaire Carl Maximowicz (during his career, he described and named more than 2,300 new plants). Fortunately for gardeners, all of these spireas—whatever their names—share common cultural needs and are now wisely grouped together.
Planting and pruning
Most Japanese spireas are container grown and best planted in spring or autumn. Preferring full sun, they will tolerate partial shade, but won’t flower as profusely. Although these spireas are willing to put up with almost any soil thrown at them, given a choice, they’d prefer a rich loam that remains moist without being waterlogged; during active growth, they require a minimum of one inch (2.5 cm) of water per week (much like turfgrass). To get them off to a good start, I add several spadefuls of compost or composted manure to the planting hole, and after installing the shrub, I top it off with an organic mulch (e.g., shredded leaves or bark chips) to keep the root run cool, discourage weed competition and conserve moisture.
Newer cultivars tend to be “self-cleaning”; in other words, new shoots grow up around the spent flowerheads, effectively hiding them from view. Nevertheless, even the most recent introductions will benefit from regular deadheading, which will encourage more flower buds to form—with older cultivars, it’s essential.
Japanese spireas bloom on new wood, so they should be pruned in late winter or early spring. Usually this annual pruning is confined to cutting away dead wood and a general shaping of the shrub; however, specimens that have outgrown their allotted space can be hard-pruned to just two inches (5 cm) above soil level to control their size. Another way to control plant size is to divide them as they begin to enter dormancy in early autumn—be sure to disturb the roots as little as possible and use a sharp spade to make the job easier.
All spireas are members of the rose family (Rosaceae), but fortunately *S. japonica* cultivars aren’t martyrs to the pests and diseases that afflict so many of their clan—including Japanese beetles. Aphids and mildew may be a nuisance some years, but are easily dealt with using organic control methods. As woody plant expert Michael Dirr notes, “Based on my experience, it is difficult to kill a spirea.”
When to opt for native spireas
In the U.S., Japanese spireas have become naturalized in many of the eastern states along stream banks and waterways, effectively crowding out native species. Although not listed as an invasive alien species in Canada, escaped populations have been reported in wetlands in Nova Scotia and Ontario. If you live near a sensitive ecosystem, opt for native species (Spiraea alba var. latifolia, S. tomentosa and S. virginiana) or choose non-flowering Spiraea japonica cultivars.
12 best Japanese spirea cultivars
(Note: All cultivars are hardy to Zone 4 except where noted)
‘Flowering Choice’ (Spiraea japonica ‘Flowering Choice’)
The result of a complicated series of crosses and selected by Tony Huber at the W. H. Perron Company (now Norseco) trial fields in Boisbriand, Quebec, in 1986; introduced by Bailey Nurseries in St. Paul, Minnesota, in 2003. A semi-dwarf variety with a rounded, compact habit, ‘Flowering Choice’ grows 16 inches (40 cm) tall by 14 inches (35 cm) wide, and produces three-inch (8-cm)-wide purplish pink blooms for 15 weeks from late spring to late summer, held above medium green foliage that turns purplish red in autumn.
Double Play Artist (S. j. ‘Galen’)
Bred by Timothy Wood (of Bloomerang lilac fame) at Spring Meadow Nursery in Grand Haven, Michigan; the result of a cross between Magic Carpet and an unknown pollen parent; introduced in 2009. A member of the Double Play Series, developed to extend the seasonal interest of spireas beyond the flowering period, Double Play Artist does just that: spring foliage emerges a rich purple-red before turning blue-green for summer, and finally burgundy in autumn. Outward-facing fuchsia-purple flowers up to 1.5 inches (4 cm) across are sweetly scented, and are produced from late spring to midsummer on a mounding, compact plant with excellent vigour. Growing 30 inches (75 cm) tall and wide, Double Play Artist is resistant to mildew.
‘Genpei’ (S. j. ‘Genpei’ syn. ‘Shirobana’, ‘Shirobori’)
Unique among the Japanese spireas for producing deep rose, pink and white flowers on the same plant—even on the same corymb—at the same time (although medium pink tends to prevail) held above lustrous light green foliage that turns russet in autumn. With a mounding, semi-dwarf habit, ‘Genpei’ grows 24 inches (60 cm) tall by 32 inches (80 cm) wide, and continues to produce new flowers sporadically throughout summer, even without deadheading. A classic, introduced from Japan in 1970.
‘Golden Carpet’ (S. j. ‘Golden Carpet’)
Also from Tony Huber at W. H. Perron in Quebec, ‘Golden Carpet’ is the result of a breeding program aimed at creating compact groundcover spireas with colourful leaves and few to no flowers. The result of a cross between two unnamed seedlings, ‘Golden Carpet’ was selected in 1984 and introduced in 2003. Growing eight inches (20 cm) tall by 16 inches (40 cm) wide, it bears small, golden leaves on a bushy, freely branching plant. Branches that come into contact with the soil surface root (or “layer”) easily and may be separated and planted elsewhere. Non-flowering ‘Green Carpet’ arose from the same cross; its small, green leaves turn reddish orange in autumn.
‘Golden Elf’ (S. j. ‘Golden Elf’)
A truly dwarf, non-flowering, golden-leaved groundcover spirea, ‘Golden Elf’ was discovered as a naturally occurring branch mutation of ‘Gold Mound’ (W. H. Perron, 1985) by Clement Paquette at Pépinière Mont-Yamaska in St-Paul-d’Abbotsford, Que., in 1995 and released in 2001. Growing just six inches (15 cm) tall by 12 inches (30 cm) wide with a spreading habit, when grown in full sun, the leaves retain their golden colour from early spring until the first frosts. Hardy to Zone 3; insect and disease resistant.
Golden Princess (S. j. ‘Lisp’)
A naturally occurring cross between the Dutch ‘Little Princess’ and British ‘Goldflame’ discovered growing in Hampshire, England, in the early 1980s and introduced by Peter Catt (Liss Forest Nursery, Hampshire); introduced to North America in 1991 by the Conard-Pyle Company in Pennsylvania. Growing 30 inches (75 cm) tall by 40 inches (1 m) wide with a gently mounding habit, Golden Princess retains its golden foliage well and flowers profusely from late spring to early autumn, producing two-inch (5-cm)-wide corymbs of bright pink flowers. New leaves emerge orange-red and slowly turn to yellow.
‘Sparkling Carpet’ (S. j. ‘Sparkling Carpet’)
From the same cross as ‘Golden Carpet’ and ‘Green Carpet’ by Tony Huber at Laval, Que., selected in 1984 and introduced in 2003. Like its non-flowering siblings, ‘Sparkling Carpet’ has a compact, mounding habit with a dense, bushy silhouette. Growing eight inches (20 cm) tall by 12 inches (30 cm) wide, its small leaves are bright red in bud and mature to a rich yellow-green with red margins. It sets off plants with purple foliage extremely well. I like growing it mixed together with random clumps of Japanese blood grass (Imperata cylindrica ‘Rubra’) beneath Black Lace elderberry (Sambucus nigra f. porphyrophylla ‘Eva’). Who needs flowers?
Double Play Big Bang (S. j. ‘Tracy’)
Another Tim Wood introduction (2010) from Spring Meadow Nursery, Double Play Big Bang is a cross between Pink Parasols Korean spirea (S. fritschiana ‘Wilma’) and an unknown S. japonica pollen parent. Growing 36 inches (90 cm) tall and wide, spring foliage emerges bright orange, changing to yellow-green in summer. Extra-large, pink flowers up to three inches (8 cm) across are produced from late spring to midsummer on a vigorous plant with a mounding, freely branching habit.
Magic Carpet (S. j. ‘Walbuma’)
A third generation seedling of self-pollinated ‘Goldflame’ and widely judged its rightful successor; hybridized by David R. Tristram at his Walberton Nursery, Arundel (West Sussex, England) and introduced in 1995. Growing 20 inches (50 cm) tall and wide with a compact, spreading habit, Magic Carpet leafs out early in spring and produces 2.5-inch (6-cm)-wide deep pink flowers in summer. The first cultivar to maintain its golden colour regardless of leaf age or light levels without reverting to dark green, its young shoots and leaves are brilliant red, changing to gold as they mature.
‘White Gold’ (S. j. ‘White Gold’)
Another selection made by Peter Catt (Greatham, Hampshire) in 1996 from several crosses involving S. j. var. albiflora and ‘Candlelight’; introduced in 2003. Growing 30 inches (75 cm) tall and wide with a compact habit, ‘White Gold’ has golden yellow-green foliage and bears dense corymbs of creamy white flowers from late spring to summer. It’s probably the best choice for gardeners who find gold and pink combinations difficult to digest.
Double Play Gold (S. j. ‘Yan’)
A further Tim Wood introduction (2009), again from a cross between Magic Carpet and an unknown S. japonica pollen parent. Growing 24 inches (60 cm) tall and wide, Double Play Gold has a spreading, compact habit with mildew-resistant golden leaves and one-inch (2.5-cm)-wide hot pink flowers from late spring to midsummer that have a faint, sweet fragrance. Dainty and delicate in appearance, but tough as nails in the garden.