Anthony Waterer spirea

Sun

Full sun to light partial shade; flowering is strongest in full sun.

Water

Moderate; water regularly while establishing, then during prolonged dry spells. Established plants tolerate some drought.

Soil

Average, well-drained soil, including clay that does not remain waterlogged; tolerates mildly acidic to mildly alkaline conditions.

Height

2-3 ft (0.6-0.9 m)

Spread

3-4 ft (0.9-1.2 m)

Flowers

Deep pink to crimson-pink, flat-topped flower clusters in early to midsummer; lighter repeat flowering may follow deadheading.

Foliage

Small, toothed green leaves, often reddish or bronze when young. Occasional shoots have cream-and-pink variegation; autumn colour is variable, sometimes yellow or reddish.

Growth

Moderate

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Cold hardy
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   1.8 ft (0.55 m)

3. After 2 years

   2 ft (0.6 m)

4. After 3 years

   2.1 ft (0.65 m)

5. After 5 years

   2.5 ft (0.75 m)

   full size

About 5 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Invasive in

the US

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Moderate

• Water deeply during dry weather through the first growing season, allowing the soil surface to dry between waterings.
• Apply 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the stems.
• In spring, top-dress with compost; use fertiliser only if growth is weak and the soil is poor.
• Remove spent flower heads before seed develops, especially where Japanese spirea escapes cultivation.
• Check around the shrub for seedlings and remove them promptly.

Pruning. In late winter or early spring, shorten the previous year's growth by about one-third and remove dead stems and some of the oldest stems at ground level; flowers form on new growth. Lightly trim spent flower clusters after the main display to encourage a smaller second flush.

Late winter

Prune before new growth begins, removing dead wood and thinning crowded old stems.

Spring

Plant when the soil is workable and not waterlogged; water thoroughly and mulch.

Late spring

Check tender shoots for aphids and water newly planted shrubs during dry spells.

Early summer

Take softwood cuttings from healthy, non-flowering shoots if more plants are wanted.

Midsummer

Trim fading flower heads before seeds ripen and water during prolonged drought.

Autumn

Remove unwanted seedlings and replenish mulch where it has become thin.

• Plant as a low informal hedge along a path or boundary, allowing room for its mature width.
• Repeat small groups through a mixed border to provide a consistent mound shape and summer colour.
• Pair with purple-flowered catmint or salvia for a long-flowering pink-and-violet combination.
• Use in front of taller shrubs to soften their bare lower stems.

Garden styles it suits: Cottage garden, Traditional, English country, Low-maintenance, Small-space and Family-friendly.

Plant it with: Catmint, Perennial salvia, Hardy geranium, Daylily, Feather reed grass and Lady's mantle.

Wildlife: Flowers provide pollen and nectar for bees and other insects. Where Japanese spirea is invasive, its spread can displace native vegetation; choose a locally suitable native shrub instead.

• Aphids can cluster on young shoots; wash them off with water and allow ladybirds and other predators to help.
• Powdery mildew may mark leaves in crowded, poorly ventilated sites; thin congested stems and avoid letting the roots become very dry.
• Waterlogged soil can cause root decline and dieback; improve drainage or move the shrub rather than increasing watering.
• Sparse flowering and loose growth usually indicate too much shade or excessive nitrogen; provide more sun and reduce feeding.

Not known to be toxic to cats, dogs, horses or people; no part is recognised as poisonous. It is an ornamental plant, not a food plant.

Where it spreads. Japanese spirea spreads by seed and is invasive in parts of the eastern and central United States, particularly the Mid-Atlantic, Appalachian and southeastern regions. It is listed as invasive in states including Pennsylvania, Virginia, North Carolina and Tennessee. Do not assume this cultivar is sterile; check local restrictions and avoid planting near natural areas where the species is invasive.

• Little Princess spirea (Spiraea japonica 'Little Princess')

  Usually forms a lower, more compact mound with paler pink flowers; Anthony Waterer has deeper pink to crimson-pink blooms.

• Douglas spirea (Spiraea douglasii)

  Usually taller and more suckering, with upright, cone-shaped pink flower clusters rather than flat-topped clusters.

• Vanhoutte spirea (Spiraea × vanhouttei)

  A much larger shrub with long arching branches and white flowers in spring rather than pink flowers in summer.

The cultivar honours English nurseryman Anthony Waterer, while japonica means 'from Japan'.

Propagation. Take softwood cuttings in early summer or hardwood cuttings during dormancy. Cuttings preserve the cultivar; seedlings do not reliably resemble the parent.

Accepted botanical name

Spiraea japonica

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

China North-Central, China South-Central, China Southeast, Japan, Myanmar, Taiwan and Tibet.

Measured

Average height 138 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.