Shasta doublefile viburnum

Sun

Full sun to partial shade; afternoon shade helps in hot climates.

Water

Moderate; keep the root zone evenly moist, especially during establishment and hot, dry weather.

Soil

Moist, well-drained soil enriched with organic matter; tolerates clay if drainage is adequate. Acidic to neutral soil is ideal.

Height

6-10 ft (1.8-3 m)

Spread

10-15 ft (3-4.6 m)

Flowers

Mid- to late spring; flat white lacecap clusters with showy sterile outer flowers surrounding small fertile flowers.

Foliage

Opposite, dark green, oval leaves with toothed edges and deeply impressed veins; often reddish-purple to burgundy in autumn.

Growth

Moderate

Care needed

Low

• Pollinators
• Wildlife
• Low allergen

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

Difficulty

Easy

Toughness

Fairly tough

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

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.9 ft (0.88 m)

3. After 2 years

   4 ft (1.3 m)

4. After 3 years

   5 ft (1.6 m)

5. After 5 years

   8 ft (2.4 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

Growth rate

Moderate

• Plant where its full width can develop without regular clipping.
• Water deeply during dry spells for the first two growing seasons; established plants also need water in prolonged drought.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the stems.
• Top-dress with compost in spring; use fertilizer only if growth is weak or a soil test indicates a deficiency.
• Avoid exposed, hot, dry sites and ground that remains waterlogged.

Pruning. Prune just after flowering, removing dead, damaged or crossing branches and, if needed, a few old stems at ground level. Avoid shearing or shortening every branch, which spoils the layered outline; late pruning also removes next spring's flower buds.

Autumn

Plant while the soil is workable and moist, allowing room for the mature spread.

Late winter

Check for broken or dead branches and remove them; leave routine shaping until after flowering.

Early spring

Refresh mulch and add a light compost top-dressing.

Late spring

After flowering, make any necessary thinning cuts without disturbing the horizontal tiers.

Summer

Water deeply during prolonged dry weather and check stressed foliage for mites or mildew.

Early summer

Take softwood cuttings if you want more plants identical to 'Shasta'.

• Use as a specimen in a broad lawn or open border, where the tiered branches can be seen from a distance.
• Place at a woodland edge with ferns and shade-tolerant perennials beneath its outer branches.
• Set behind a low mixed border to provide spring flowers and a strong branching framework.
• Combine with other deciduous shrubs for a loose screen with seasonal flowers and autumn colour.

Garden styles it suits: Woodland, Japanese, English country, Traditional, White garden and Autumn colour.

Plant it with: Japanese maple, Oakleaf hydrangea, Hosta, Japanese painted fern, Astilbe and Epimedium.

Wildlife: The small fertile flowers attract visiting insects, and birds eat the fruits. A genetically different doublefile viburnum flowering at the same time usually improves fruit set; two plants of 'Shasta' are not genetically different pollination partners.

• Leaf scorch and premature leaf drop in heat or drought: water deeply, mulch and provide afternoon shade in hot locations.
• Powdery mildew in crowded or stressed plants: improve airflow, avoid drought stress and remove badly affected fallen leaves.
• Spider mites in hot, dry conditions: check leaf undersides, rinse foliage with water and use insecticidal soap if an infestation persists.
• Root rot in waterlogged soil: improve drainage or move the shrub to a better-drained site; do not keep watering saturated ground.

Not known to be toxic to cats, dogs or horses. It is not generally regarded as poisonous to people, but the ornamental fruits are not recommended for eating and may cause stomach upset if eaten in quantity.

Where it spreads. The species has escaped cultivation and is considered invasive in parts of the eastern United States, including Pennsylvania and Virginia. Birds can spread its seeds into woodland; 'Shasta' can produce viable seed, so check local guidance before planting near natural areas.

• Japanese snowball viburnum (Viburnum plicatum f. plicatum)

  Has rounded, snowball-like heads of sterile flowers rather than Shasta's flat lacecap clusters; it normally produces no fruit.

• Mariesii doublefile viburnum (Viburnum plicatum f. tomentosum 'Mariesii')

  Has very similar tiered branches and white lacecap flowers. 'Shasta' generally has larger flower clusters and a broader, lower habit, but young plants can be difficult to distinguish without a reliable label.

• Japanese hydrangea vine (Hydrangea hydrangeoides)

  Also bears white lacecap flowers but is a climbing plant with aerial roots, not a self-supporting shrub with horizontal tiers.

Plicatum means pleated, referring to the strongly veined leaves, tomentosum refers to their hairs, and doublefile describes the paired rows of flower clusters along the branches.

Propagation. Root softwood cuttings in early summer under humid conditions, or layer a low branch. Seedlings will not reliably retain the characteristics of 'Shasta'.

Accepted botanical name

Viburnum plicatum Viburnum plicatum f. tomentosum 'Shasta' is an older name for Viburnum plicatum.

In the US and Canada

Introduced in the lower 48 states.

Native range

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

Measured

Average height 300 cm.

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