Masterwort 'Shaggy'

Sun

Partial shade; full sun in cool climates if the soil stays consistently moist. Provide afternoon shade in warmer areas.

Water

Keep evenly moist during growth, watering deeply during dry spells. Avoid both prolonged drought and waterlogged soil.

Soil

Humus-rich, moisture-retentive but well-drained soil; tolerates clay improved with organic matter. Suitable for acidic, neutral or alkaline soil.

Height

2-3 ft (0.6-0.9 m)

Spread

1.5-2 ft (0.45-0.6 m)

Flowers

Late spring through summer, sometimes repeating into early autumn after cutting back; greenish-white to pale pink flower heads surrounded by long white, green-tipped bracts.

Foliage

Basal clumps of mid-green, deeply divided, toothed leaves; dies back for winter.

Growth

Moderate

Care needed

Medium

• Pollinators
• Deer resistant
• Cold hardy
• Low allergen

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

Difficulty

Moderate

Toughness

Fairly tough

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

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.5 ft (0.45 m)

3. After 2 years

   2 ft (0.6 m)

4. After 3 years

   2.5 ft (0.75 m)

   full size

About 3 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

Growth rate

Moderate

• Water deeply whenever the root zone begins to dry, especially during the first growing season.
• Apply compost or leaf mould in spring, keeping it clear of the crown.
• Use a moisture-retaining organic mulch to keep roots cool.
• Avoid heavy feeding; on poor soil, apply a light general-purpose feed in spring.
• Divide congested clumps in spring every three to four years if flowering declines.

Pruning. Cut spent flower stems back to the basal leaves to encourage another flush and prevent unwanted seedlings. Remove dead foliage in late autumn or before new growth starts in spring; cut back scorched summer foliage only if you can keep the plant watered while it regrows.

Early spring

Remove remaining dead foliage and check that the crown is not buried under mulch.

Spring

Plant or divide clumps, water thoroughly and top-dress with compost.

Late spring

Check soil moisture as flower stems develop; water during dry spells.

Summer

Remove fading flower stems to encourage repeat flowering and limit self-seeding.

Late summer

Continue watering during drought; trim badly scorched leaves if fresh growth is possible.

Late autumn

Remove collapsed foliage, or leave sound stems until spring for winter shelter.

• Plant in groups through a partly shaded border, where the pale bracts show against darker foliage.
• Combine with hardy geraniums and lady's mantle for a soft cottage-garden planting.
• Use beside hostas and ferns at a bright woodland edge with moist, drained soil.
• Thread through a white or cool-coloured border for fine texture between larger flowers.
• Include in a cutting border for fresh or dried arrangements.

Garden styles it suits: Cottage garden, English country, Woodland, White garden, New perennial (prairie) and Blues and silvers.

Plant it with: Hardy geraniums, Lady's mantle, Hostas, Japanese painted fern, Astilbes and Siberian irises.

Wildlife: The small, accessible flowers attract bees, hoverflies and other flower-visiting insects.

• Brown leaf edges and early dieback usually indicate dry soil or excessive heat: water deeply, mulch and provide afternoon shade.
• Slugs and snails may eat emerging shoots: inspect young growth and use barriers or locally approved iron-based slug bait as needed.
• Powdery mildew can develop on stressed or crowded plants: maintain soil moisture, improve spacing and remove badly affected leaves.
• Poor growth or crown rot in waterlogged soil: improve drainage or move the plant to a raised, moisture-retentive but freely draining bed.

Not known to be toxic to people, cats, dogs or horses, and no particular part is established as poisonous. It is an ornamental rather than a food plant; toxicity information specific to this cultivar is limited.

• Great masterwort (Astrantia major)

  Typical plants have shorter, less conspicuously shaggy bracts and variable white or pink colouring; 'Shaggy' has particularly long, narrow, white bracts with green tips.

• Largest masterwort (Astrantia maxima)

  Usually has broader, pink bracts forming a more solid-looking collar, and leaves divided into three main sections rather than the more deeply hand-shaped leaves of great masterwort.

Astrantia comes from the Greek word for star, referring to the star-like ring of bracts around each flower head.

Propagation. Divide established clumps in spring to retain the cultivar's characteristics. Seedlings may differ from the parent, so do not rely on seed to reproduce 'Shaggy'.

Accepted botanical name

Astrantia major involucrata

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