Japanese spirea
Spiraea japonica
Japanese spirea (Spiraea japonica) is a shrub suited to the Colorado Front Range. It matures to about 2 to 4 ft tall and 3 to 4 ft wide, needs medium water, and prefers full sun to partial shade. Tough, colorful foliage + summer-long pink blooms. Cut hard each spring for best form.
On the CSU listmedium water2 to 4 ft tall and 3 to 4 ft wide
Photos
- Photo 1: no rights reserved
- Photo 2: (c) Alina Martin, some rights reserved (CC BY)
- Photo 3: (c) Alina Martin, some rights reserved (CC BY)
At a glance
Will it survive here?
- Hardiness zones
- USDA 3 to 8
- Water needs
- medium water
- Sun
- Best in full sun; tolerates partial shade.
- Soil
- clay, loam
- Soil pH
- 6.0 to 7.5
- Hail tolerance
- moderate
- Wind tolerance
- moderate
- Salt tolerance
- low
How big, what shape?
- Mature size
- 2 to 4 ft tall and 3 to 4 ft wide
- Planting spacing
- ~4 ft apart (3 ft for a hedge/screen)
- Growth rate
- Moderate
What it looks like, and when
- Bloom time
- early summer, mid summer
- Bloom color
- pink, red
- Bloom length
- Long (several weeks)
- Fall color
- Orange, gold
- Foliage
- Deciduous
Who else benefits
- Pollinator value
- high
- Deer
- Not rated
- Colorado native
- No
Also worth knowing
- Fire rating
- Not rated
Things to know before you plant
- Spreads aggressivelySelf-seeds in moist conditions; some states list as invasive
Common problems on the Front Range
- Aphids
- Spider mites in heat
These are general tendencies for this group of plants on the Front Range, not a diagnosis. Many are stress-driven and preventable with good siting and watering. For a specific plant or an active problem, consult a certified arborist or your local CSU Extension office.
Planting & establishment
- Pruning: hard (rejuvenation).
Frequently asked questions
- Is Japanese spirea good for the Colorado Front Range?
- Yes, Japanese spirea is a well-suited shrub for Colorado's Front Range.
- What should I know before planting Japanese spirea?
- The main things to know: Self-seeds in moist conditions; some states list as invasive
- How big does Japanese spirea get?
- It matures to about 2 to 4 ft tall and 3 to 4 ft wide.
- How far apart do I plant Japanese spirea?
- Space Japanese spirea about 4 ft apart for a full, natural form, or about 3 ft apart for a faster hedge or screen.
- Is Japanese spirea hardy on the Front Range?
- Japanese spirea is hardy in USDA 3 to 8. The Colorado Front Range spans roughly USDA 4b to 6a, so it is well within range.
- How much water does Japanese spirea need?
- It needs medium water once established.
- How fast does Japanese spirea grow?
- Japanese spirea is a moderate-growing shrub. Growth rate depends on water and site conditions on the Front Range.
- What color does Japanese spirea turn in fall?
- Japanese spirea turns orange and gold in autumn. Fall color intensity varies with the season and site on the Front Range.
- Is Japanese spirea native to Colorado?
- No. It is not a Colorado native, but it grows well on the Front Range.
- Is Japanese spirea prone to pests or disease on the Front Range?
- Japanese spirea can be affected by aphids and other issues common to this group on the Front Range. These are general tendencies, not a diagnosis, many are stress-driven and preventable with good siting and watering. For a specific plant or an active problem, consult a certified arborist or CSU Extension.
- How long does Japanese spirea bloom?
- Japanese spirea blooms for several weeks, a long-season performer on the Front Range. Bloom timing shifts a week or two with elevation and spring weather.
