Korean feather reed grass

Korean feather reed grass: how do you recognise it?

Habit

Upright, compact clump about 60 cm wide; about 1 m tall with the plumes.

Leaves

Broad and strap-shaped, fresh green and slightly arching; yellow to beige in autumn.

Flowers

Thick, fluffy, slightly slanting plumes from August to October; soft pink to silvery purple, later beige.

Seed

The plumes stay on all winter; it sometimes self-seeds a little.

Roots

A dense clump without long runners.

Flowering: August–October · Plants: March–May · Pruning: March

Why grow it?

• One of the finest grasses for late summer and autumn, when the border starts to look tired.
• The pink, fluffy plumes sparkle when backlit, with morning dew and frost.
• Also tolerates light shade, where most ornamental grasses fail.
• It does not spread: a neat clump that stays in its place.
• Strong winter structure: the plumes stay upright until March.
• Little work: cut back once a year.

Korean feather reed grass: where does it grow best?

• Sun or partial shade; in light shade it still flowers well, in deep shade the stems flop.
• Ordinary garden soil: sand, loam or clay, acid to chalky.
• Normally moist: it dislikes drying out in summer and wet feet in winter.
• Plant it so that the low autumn sun shines through the plumes from behind.
• Allow 50–60 cm between plants.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

1 m tall, 0.6 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Japanese anemone: Pink and white flowers in the same late summer, also in partial shade.
• Michaelmas daisy: Purple and blue flowers beside the pink plumes.
• Bugbane: White flower spikes in autumn, in the same partial shade.
• Ice plant: Pink flower heads that bloom at the same time.
• Black-eyed Susan: Yellow flowers with a dark centre as a warm contrast.

Korean feather reed grass: when and how to plant it?

Plant in March–May.

1. Plant in March, April or May, as the soil warms up.
2. Dig a hole twice as wide as the root ball and mix in some compost.
3. Set the plant at the same depth as it was in the pot and firm the soil well.
4. Leave 50–60 cm between plants; it looks best in a group of three or five.
5. Water generously straight away, then weekly in dry spells during the first summer.

Care

Watering

In dry spells during the first year; after that only in long dry periods, especially on sandy soil.

Feeding

A little compost in April is enough; too much fertiliser makes the stems floppy.

Cutting back

In March, cut the whole clump back to 10–15 cm above the ground.

Rejuvenating

Divide every four or five years, when the clump goes bare in the middle.

Seedlings

Weed out unwanted seedlings while they are small.

Tip: Plant it where the low autumn sun shines through the plumes from behind, for example to the west or south of a seating area: then they really sparkle like diamonds.

Korean feather reed grass: when to prune it?

Pruning months: March.

When: Cut back in March, before the new leaves appear; leave the plumes standing all winter.

How:

• Tie the clump together with string and cut it off in one go with shears or secateurs, 10–15 cm above the ground.
• Do not leave it too late: if the new shoots are already tall, you will cut off their tips.
• Chop up the cut stems before adding them to the compost heap.

Caution: Do not cut back in autumn: the old clump protects the heart of the plant and gives insects shelter in winter.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In April, as new growth begins, lift a clump and cut it into pieces with a sharp spade; replant straight away and water.

Seed

Sow ripe seed in spring in pots, barely covering it; seedlings flower after one or two years.

Korean feather reed grass: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy, to about −25 °C: no protection needed.
• Leave the plumes standing: they stay upright and look superb with frost or snow.
• In a large pot it can stay outside; raise the pot on feet so that water can drain away.

Diseases and pests

• Flopping stems: Too much shade or fertiliser makes the clump floppy. Give it a lighter spot and feed less.
• Bare centre: Old clumps die out in the middle. Divide them in spring and replant the outer parts.
• Seedlings: It sometimes self-seeds in the border. Weed out the seedlings while young.
• Brown leaf tips: In drought the leaf tips wither. Water during long dry spells.

Through the year

• January: Leave the plumes standing. Lovely with frost.
• February: Leave standing.
• March: Cut back to 10–15 cm. Add compost.
• April: Plant or divide.
• May: Plant. Water after planting.
• July: Water in dry spells.
• August: First pink plumes.
• September: Full flower: backlit plumes.
• October: Flowering. The plumes turn beige.
• November: Leave the plumes for winter.
• December: Winter structure.

Did you know?

• The name Calamagrostis comes from the Greek kalamos (reed) and agrostis (a kind of grass).
• It is sometimes confused with feather reed grass ‘Karl Foerster’ (Calamagrostis × acutiflora), but that flowers as early as June and does not set viable seed.
• The name Korean feather reed grass refers to its origin and its feathery plumes.