Masterwort 'Roma'

Sun

Partial shade; full sun where summers are cool and the soil stays moist. Give afternoon shade in warmer gardens.

Water

Keep evenly moist, especially during establishment and flowering; do not leave the roots waterlogged.

Soil

Humus-rich, moisture-retentive but well-drained soil. Tolerates clay, loam and a range of soil pH levels.

Height

2-3 ft (0.6-0.9 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Early to late summer, sometimes continuing into early autumn after deadheading; soft pink flowers with silvery-pink bracts.

Foliage

Green, deeply palmately lobed leaves form a low mound beneath slender, branching flower stems. Dies back in winter.

Growth

Moderate

Care needed

Medium

• Pollinators
• 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 during dry spells before the leaves begin to wilt.
• Mulch each spring with compost or leaf mould, keeping it clear of the crown.
• Avoid heavy feeding; a spring compost mulch is usually enough.
• Use discreet supports if stems lean in exposed sites or rich soil.
• Divide congested clumps in spring when flowering begins to decline.

Pruning. Cut spent flower stems back to the basal leaves to encourage further flowering. Remove dead stems and foliage in late autumn or late winter; if summer foliage becomes scorched, trim it back and water to encourage fresh growth.

Early spring

Remove remaining dead growth and divide congested clumps as new shoots appear.

Spring

Plant into moist, prepared soil and apply a compost or leaf-mould mulch.

Late spring

Check young shoots for slugs and snails, and add supports if needed.

Summer

Water during dry weather and remove faded flower stems regularly.

Early autumn

Plant new specimens while the soil is moist and still warm.

Late autumn

Remove collapsed or diseased foliage; leave sound stems until late winter if preferred.

• Plant in groups through a partially shaded border for a repeated layer of soft pink flowers.
• Combine with ferns, hostas and hardy geraniums along a moist woodland edge.
• Use beneath roses where the soil receives enough moisture and the canopy is not too dense.
• Mix with fine-textured grasses and summer perennials for an informal, airy planting.

Garden styles it suits: Cottage garden, English country, Woodland, New perennial (prairie), Romantic rose garden and Pastel border.

Plant it with: Hardy geraniums, Hostas, Lady's mantle, Astilbes, Japanese painted ferns and Roses.

Wildlife: The small, accessible flowers attract bees, hoverflies and other pollinating insects.

• Slugs and snails can damage emerging leaves: inspect at dusk, remove by hand and use wildlife-conscious controls where necessary.
• Powdery mildew may develop in dry, crowded conditions: keep roots moist, improve spacing and remove badly affected foliage.
• Brown leaf edges, wilting or early dormancy usually indicate heat or drought stress: water deeply, mulch and provide afternoon shade.
• Crown or root rot can occur in waterlogged soil: improve drainage and avoid planting the crown too deeply.

Not known to be toxic to people, cats, dogs or horses. No particular part is recognised as poisonous, although specific veterinary information is limited and it should not be treated as an edible plant.

• Great masterwort (Astrantia major)

  The species has the same divided leaves and starry flower heads, but flower colour is variable and often paler or greener. Colour alone cannot reliably distinguish 'Roma' from other pink cultivars;

• Largest masterwort (Astrantia maxima)

  Usually has broader pink bracts, fewer and larger-looking flower heads, and leaves divided into three main sections rather than the more numerous finger-like lobes typical of Astrantia major.

• Masterwort (Imperatoria ostruthium)

  A different plant with broad leaflets and open, flat clusters of small white flowers, without the conspicuous pink, star-shaped bracts of 'Roma'.

Astrantia is generally linked to the Greek word for star, referring to the star-like flower heads, while major means larger.

Propagation. Divide established clumps in spring, keeping several healthy shoots and roots on each section. Division preserves 'Roma'; seed-grown plants will not reliably match the cultivar.

Accepted botanical name

Astrantia major

In the US and Canada

Introduced in St. Pierre and Miquelon.

Native range

Albania, Austria, Belarus, Bulgaria, Czechoslovakia, France, Germany, Greece, Hungary, Italy, North Caucasus and Poland.

Measured

Soil pH 6.5 to 7. Average height 40 cm.

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