Bumald Spirea

(Rosaceae - Rose Family)

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• Form
  • small ornamental shrub
  • slowly maturing to 3' tall by 4' wide
  • rounded clump growth habit
  • slow growth rate (although basal suckers have a medium growth rate)

• Culture
  • full sun to partial shade
  • performs best in full sun in moist, well-drained soils, but is very urban tolerant and adaptable to poor soils, clay soils, dry soils, soils of various pH, heat, drought, and light shearing or heavy pruning
  • propagated primarily by rooted stem cuttings, although seeds or division of mother plants are also possible
  • Rose Family, with numerous potential diseases and pests, which usually do not manifest themselves in this slow-growing yet vigorous hybrid shrub
  • abundantly available in container form, with several common cultivars
  • takes well to a light shearing after flowering, in order to deadhead, restore the foliage effect, and encourage a light rebloom later in the season
  • foliage color variants must be placed in full sun to achieve their full potential with intense foliage colors; otherwise, placement in partial sun to partial shade causes the foliage to gravitate towards a chartreuse or light green color

• Foliage
  • alternate, ovate, serrated, having a short petiole, and variable in leaf color, depending upon the specific cultivar or hybrid
  • usually emerging as a bronzed or reddish color, and quickly transitioning to the color of choice for that particular selection
  • any selection may have sport branches that either have yellow-splotched leaves among the normal green-foliaged background, or green leaves among the alternative solid color; in either case, the sport stem must be pruned back all the way to its point of origin in order for it to be effectively removed
  • fall color is often greenish-purple on green cultivars, lavendar-red to orange-red on 'Gold Flame', and chartreuse on 'Gold Mound'

• Flowers
  • light pink, deep mauve, carmine, or dark lavender (depending upon cultivar), in late May and early- to mid-June (and sometimes with a second flush of less intense flowering later in the season)
  • flowering on the new growth of the season, in 2" to 3" diameter flat-topped, fine-textured inflorescences that cover the canopy and are very showy

• Fruits
  • clusters of fine-textured brown fruits, pedicels, and peduncles occur above the foliage, but are not ornamental and detract from the attractive foliage
  • if left alone, the flat-topped fruit heads persist throughout the Winter into the next season and are a good identification feature, but they are not showy and ideally should be sheared off (deadheaded or "feather-pruned") to make the shrub more tidy

• Twigs
  • stems with subtle ridges are relatively unbranched, upright or radiating from the central clump, of bright tan color on the new growth, maturing to dark brown on the older stems

• Trunk
  • not applicable

• ID Summary
  • ovate leaves of various mature colors (typically dark green, lime, or golden-orange, per cultivar) at first emerge in early Spring as reddish-bronzed small leaves dotting the thin but densely upright and relatively unbranched stems
  • rounded shrubs are no more than 3.5' tall at maturity, and are profusely laden with pink, mauve, or carmine flowers in late Spring to early Summer, giving rise to fine-texured, wispy, flat-topped fruiting heads, that if unsheared will persist into the following year

• Function
  • entranceway, specimen, raised planter, border, facer, group planting, or mass planting shrub

• Texture
  • fine texture in foliage and when bare
  • thick density in foliage and when bare

• Assets
  • very urban tolerant (especially to heat, drought, and poor soils)
  • changing seasonal foliage colors for most cultivars
  • attractive, long-lasting, flat-topped inflorescences in late Spring and early Summer

• Liabilities
  • moderate suckering from the base, combined with its slowly spreading growth habit, may cause it to spread slightly beyond its originally intended space (this can be remedied by heaving shearing or moderate to heavy pruning, or it can be an asset in group or mass plantings that are allowed to naturalize)
  • occasional stem sports give rise to unsightly foliage sports, which detract from the otherwise fine foliage canopy
  • 'Goldflame', when critiqued as to its colors during intense flowering, has profuse pink flowers just above the intense gold-orange foliage - not a good combination, in juxtapositioning cool and warm colors so closely together

• Habitat
  • zones 3 to 8
  • both parents (Spiraea albiflora X Spiraea japonica) are native to Japan

• Alternates
  • common and dependable standard-issue shrubs (Berberis thunbergii atropurpurea 'Crimson Pygmy', Euonymus alata 'Compacta', Syringa patula 'Miss Kim', Taxus x media 'Densiformis', Thuja occidentalis 'Smaragd', etc.)
  • shrubs with good alternative foliage color (Berberis thunbergii atropurpurea, Cotinus coggygria, Euonymus fortunei, Prunus x cistena, etc.)
  • shrubs with late Spring to early Summer inflorescences (Itea japonica, Philadephus virginalis, Spiraea japonica, etc.)

• Variants
  • many cultivars and complex hybrids exist, with new ones emerging yearly, and most are in the 3' tall and 3' wide category; the three most common are:
  • Spiraea x bumalda 'Anthony Waterer' - the old standard, with deep green foliage that initially emerges bronzed, and having deep carmine to dark mauve inflorescences
  • Spiraea x bumalda 'Gold Flame' - emergent foliage is a constant transition from red to copper to yellow-orange to gold-medium green, then becoming orange-burgandy in Autumn, with pink inflorescences
  • Spiraea x 'Gold Mound' - a more complex hybrid, with new foliage that is a vibrant yellow-green or lime-green that persists all Summer, with shell-pink inflorescences
  • Gold Flame Spirea, Gold Mound Spirea, and Crimson Pygmy Barberry are the three most common deciduous shrubs of small stature in landscapes of the Eastern and Midwestern United States

• Translation
  • Spiraea is from the Greek, denoting a plant used in wreaths or garlands.
  • x indicates the hybrid origin.
  • bumalda is named after Bumaldus, a person.

• Purpose
  • Bumald Spirea is a hybrid shrub with many attractive foliage-color variants, plus a consistent three-week heavy bloom period in late Spring or early Summer.

• Summary
  • Spiraea x bumalda is known as a relatively compact small shrub that has multi-season appeal: vibrant Spring and Summer foliage (being either green or more frequently alternative warm colors), beautiful flat-topped inflorescences (carmine, pink, or mauve, in late Spring and early Summer), and sometimes with good fall color.