Great masterwort

Great masterwort: how do you recognise it?

Habit

Loose clump with branching, upright stems, 60–90 cm tall and 40–50 cm wide.

Leaves

Palmate and deeply cut into three to seven lobes, with toothed edges; dark green.

Flower

Domed heads of tiny flowers in a ruff of stiff, papery bracts, 2–4 cm across; from June to August.

Colour

Greenish white, pink or wine red, often with green or pink tips to the bracts.

Roots

A compact rootstock; the clump spreads slowly.

Flowering: June–August · Plants: March–April and September–October · Pruning: March and July

Why grow it?

• Flowers for weeks, from June to August, and again in late summer after cutting back.
• A lovely cut flower that lasts well in the vase and also dries beautifully.
• Bees and other insects like to settle on the flower heads.
• Grows in sun and partial shade, in places that do not dry out.
• Fully hardy and easy in the border.

Great masterwort: where does it grow best?

• Sun or partial shade; in full sun only if the soil stays moist.
• Humus-rich loam or clay that holds moisture, from slightly acid to chalky.
• Normally moist to moist: it does not cope well with drying out in summer.
• Allow 40–50 cm between plants; it looks best in small groups.

Light

Sun and partial shade

Soil type

Loam or clay

Acidity

Not fussy

Moisture

Normal or wet

Size

0.7 m tall, 0.45 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Cranesbill: Low blue or pink flowers at its feet, also in partial shade.
• Lady’s mantle: Soft green leaves and lime-green flowers as an edging.
• Hosta: Large leaves beside the delicate flower heads, in the same moist soil.
• Foxglove: Tall spikes in June, in the same partial shade.

Great masterwort: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October.
2. Dig a hole twice as wide as the pot and mix in compost.
3. Set the plant at the same depth as it was in the pot and firm the soil well.
4. Keep 40–50 cm apart and plant in groups of three to five.
5. Water in generously straight away, and again in dry spells during the first year.
6. Mulch around the base with leaf mould to hold in moisture.

Care

Water

Keep the soil moist, especially in dry summers; in drought the leaves scorch.

Feeding

A layer of compost around the base in spring.

Cutting back

After the first flush, usually in July, cut back flower stems and old leaves; a second flush follows.

Self-seeding

If you do not want seedlings, remove spent flowers before they set seed.

Cut flowers

Cut the stems when the heads are fully open; they last a long time in the vase.

Tip: Cut the flowers for the vase when they are fully open: they then stay fresh for a long time, and you can also hang them upside down to dry.

Great masterwort: when to prune it?

Pruning months: March and July.

When: After the first flush, usually in July, cut the clump back. In March, remove the old, withered leaves.

How:

• After the first flush, cut the flower stems and old leaves back to just above the ground.
• Then water and add some compost: within a few weeks fresh leaves and a second flush appear.
• In March, cut away dead leaves and stems, before the new shoots appear.

Caution: Seedlings from cultivars often do not resemble the parent. To keep the colour true, remove spent flowers in good time.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April or in September, lift the clump, split it into pieces with roots and shoots, and replant at once.

Seed

The seed needs a cold spell to germinate: sow fresh seed in a pot in autumn and leave it outside over winter. Seedlings from cultivars do not always resemble the parent.

Great masterwort: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: in Belgium no protection is needed.
• The top growth dies back and sprouts again in March–April.
• A layer of compost in autumn protects the roots and feeds the soil.

Diseases and pests

• Powdery mildew: White powder on the leaves, especially in dry weather. Water, remove affected leaves and cut back after flowering.
• Slugs: They eat the young leaves in spring. Pick them off in the evening.
• Scorched leaves: Brown leaf edges in sun and drought. Water and mulch the soil.
• Too many seedlings: It self-seeds freely. Remove spent flowers or weed out the seedlings while small.

Through the year

• March: Cut away old leaves. Give compost. Plant or divide.
• April: Plant. Watch for slugs.
• May: Mulch. Water in dry spells.
• June: Flowering begins. Cut flowers for the vase.
• July: Flowering. Cut back after the first flush.
• August: Second flush begins. Water in dry spells.
• September: Late flowers. Plant or divide. Sow fresh seed.
• October: Plant. Leave seed pots outside.
• November: Spread compost over the clump.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Its Dutch name, little Zeeland button, refers to the round silver and gold buttons of the traditional Zeeland costume.
• The name Astrantia probably comes from the Latin aster, star, after the star-shaped ruff of bracts.
• What looks like a single flower is actually a head of dozens of tiny flowers inside a ruff of bracts.