By Derek Devine
Abstract
The
purpose of this web page is to give information about the propagation,
use, location, and culture of Spiraeas.Also,
I will include some examples of the many cultivars of Spiraeas.Since
most spiraeas are native to central and East Asia, I will focus on the
Japanese Spiraea�Spiraea japonica.
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DEFINITION:any
plant of the genus Spiraea, Northern Hemisphere deciduous shrubs
of the family Rosaceae (rose
family). Most are indigenous to central and E Asia, whence come most of
the popular ornamental species, e.g., the bridal wreath (S. x prunifolia),
native to Japan, and its similar hybrid S. vanhouttei. In these
species the fragrant, spirelike flower clusters typical of the genus are
borne on long, arching branches. Spiraeas native to North America include
the hardhack, or steeplebush (S. tomentosa), a local source of astringent
and tonic, and the meadowsweets (several species). The name meadowsweet
is also applied to the related genus Filipendula, tall, hardy perennials
(also often cultivated) formerly classified as Spiraea because of
the similar showy blossoms. Filipendula includes the Eurasian dropwort
(F. hexapetala), the queen of the meadow (F. ulmaria), now
naturalized in the United States, and the North American queen of the prairie
(F. rubra). Spiraeas are classified in the division Magnoliophyta,
class Magnoliopsida, order Rosales, family Rosaceae.
(The Columbia Encyclopedia, Sixth Edition) |
Japanese Spiraea
Description
Japanese spiraea is an erect, multi-stemmed deciduous shrub that
gets 2-6' tall with a similar spread. The slender reddish brown stems may
be hairy or glabrous. They bear alternate ovate leaves that are 1-3" long
and usually paler on their undersides. The leaves have toothed margins,
wedge-shaped bases, and pointed tips. Leaf color varies from chartreuse
to blue-green to bronze, orange, red, or burgundy with variety and season.
Flat-topped clusters (corymbs, to be technical) of pink flowers are displayed
at the tips of the wiry branches. In the most common forms, the pink color
results from a mix of light and dark pink that gives the blossom a pixilated
appearance. Small capsules hold seeds about 1/10 inch long. The species
Spiraea
japonica is an upright shrub, 4-6' tall.
Cultivars
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Bumalda spirea (cv.
'Bumalda'),
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Spreading shrub, only
2-3' tall
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'Alpina' or Daphne spirea
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Low, dense, spreading,
slow-growing groundcover type with pink flowers and small bluish-green
leaves that turn red and orange in fall;
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'Magic Carpet'
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Compact shrub that has
dark pink flowers and leaves that emerge red, mature to bronze, then change
to deep red in the fall;
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'Neon Flash'
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Rosy-red-flowered 4'
shrub with leaves that start out reddish and retain a purplish tinge;
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'Shibori' or peppermint
stick spirea
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Low mound-shaped shrub
that bears multi-colored white, pink, and red flowers all summer;
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'Anthony Waterer'
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2-3' bush with maroon-tinged
foliage and reddish-pink flowers
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�Dolchica�
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2' shrub with bright
pink flowers and deeply incised leaves that emerge purple
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�Froebelii'
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Especially cold-tolerant
(to Zone 3) variety that has purplish new growth and produces rosy-pink
flowers off-and-on through the early summer
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'Goldmound'
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Compact 1-3' pink-flowered
shrub with creamy chartreuse-yellow foliage that turns rusty gold with
red tips in the fall.
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Location
Not surprisingly, Japanese Spiraea comes from Japan. It also is considered native to Korea and China. It has naturalized in North America from New England south through the Appalachians into Tennessee and Georgia, and west to Indiana. Japanese Spiraea usually grows along stream bottoms and on seepage slopes, but readily invades forest edges and openings, old fields, roadsides, and utility rights-of-way.
Culture
Japanese spiraea will grow in a wide variety of soils, including
those on the alkaline side, but it prefers a rich, moist loam. These shrubs
appreciate manure and thrive on organic mulch. Since they bloom on the
current season's growth, Japanese Spiraea should be pruned in winter or
early spring. They can be cut all the way to the ground. After the flowers
fade, shear them off to stimulate a second flush of growth and more flowers.
Mowing will control expansion of a planting, but the stems will re-sprout,
so repeated cutting will be a long-term necessity. Spiraeas may suffer
minor damage from a variety of pests and diseases, but they are not prone
to any major problems. Aphids occasionally are a nuisance in the spring.
Propagation
Usage
Tall forms are grown as hedges, low screens, or foundation shrubs.
Low-growing forms are used as groundcovers or in borders.
