Common bent

How to recognise it

Growth form

Perennial grass of 20–60 cm forming loose turf, with short rhizomes and sometimes short runners above ground.

Leaf

Narrow and flat, 2–5 mm wide, green to greyish green and fairly soft; the ligule at the base of the leaf blade is very short (up to 2 mm) and cut off square.

Flower

An open, widely spreading panicle of 5–15 cm with fine, hair-like branches and hundreds of tiny purplish spikelets of 2–3 mm, each with a single flower; flowers in June–August.

Fruit/seed

Very small, light seeds spread by wind and by animals; there are thousands in a gram.

Stem

Thin, smooth stems, upright or bent at the base.

Confusion with

Creeping bent has a long, pointed ligule (up to 6 mm), long runners above ground and a panicle that closes up again after flowering. Black bent is more robust, with a long ligule. In common bent the panicle stays open and the ligule is short and blunt.

Flowering: June–August · Pruning: July and September

Why grow it?

• A food plant for caterpillars of grassland butterflies such as the small heath and the meadow brown, which live on fine grasses.
• The base grass of unimproved grassland: it grows fairly low and open, leaving room for flowers such as harebell, mouse-ear hawkweed and sheep’s sorrel.
• Its airy, pinkish-red panicles look wonderful in June–August against the light or covered in dew.
• A tough grass for a wildlife lawn on sandy soil: it copes with poor soil, drought and trampling.
• Seed-eating birds such as sparrows eat the seeds, and spiders, beetles and grasshoppers shelter in the turf.

Common bent: where does it grow best?

• In the wild: dry to moist unimproved grassland, heath and heath edges, verges, dykes, open woodland, woodland edges, old dunes and poor pastures.
• Sun to light partial shade.
• Poor, acid to neutral sandy or loamy soil; copes with drought, but also grows on moist soil.
• In the garden: as a base grass in a wildlife lawn, a poor flower meadow or a heather garden on sandy soil.

Goes well with

• Harebell: Blue bells in summer among the fine grass on poor sandy soil.
• Sheep’s sorrel: Reddish-brown flower spikes and a food plant for the small copper.
• Mouse-ear hawkweed: Yellow flowers above a low, grey-green carpet on poor soil.
• Red fescue: Another fine grass; together they form the base of a poor wildlife lawn.
• Heather: In a heather garden, bent forms the grassy edge around the heather.

Common bent: when and how to plant it?

1. Buy seed of native origin from a specialist seed supplier or nursery, preferably in a mix with other fine grasses and wild flowers; do not take turf from the wild.
2. Sow in September or in April, when the soil is moist; grasses do not need a cold period.
3. Clear the soil of weeds and rake it to a fine tilth. On rich soil, make it poorer first: remove the top layer, or mow for a few years and remove the cuttings.
4. Mix the fine seed with dry sand for even spreading, broadcast it, rake it in only very lightly at most and roll or tread it in.
5. Keep the soil moist until the seedlings are up after 1–3 weeks.
6. For a lawn or meadow, sow it together with other fine grasses such as red fescue and sweet vernal grass.

Care

Water

Only after sowing, until the seedlings are up. In a dry summer it turns brown, but greens up again after rain.

Feeding

Do not feed: on poor soil it stays fine and low and flowers keep their place. Fertiliser gives coarse grasses the upper hand.

Mowing

Flower meadow: mow twice a year, in July and September, and remove the cuttings. Wildlife lawn: every 2–4 weeks at 5–8 cm.

Spreading

It spreads slowly by short rhizomes. Cut the edges along a border.

Letting seed fall

After the July cut, leave the hay for 2–3 days so the seeds can drop out; then remove it.

Tip: Want a flowery lawn on sandy soil? Never feed it, do not mow shorter than 5 cm and remove the cuttings: common bent will then become the main grass by itself and flowers will get room.

Pruning and mowing

Pruning months: July and September.

When: In July and September, as the mowing of a flower meadow; a wildlife lawn is mown from April to October.

How:

• Mow with a scythe, brush cutter or bar mower at a height of 5–10 cm.
• Leave the cuttings for 2–3 days to dry and drop their seed, then remove them.
• Always leave a strip or a few patches uncut: caterpillars, eggs and insects overwinter there in the stems and turf.
• In a wildlife lawn: do not mow shorter than 5 cm or too often, so flowers can bloom.

Caution: Avoid flail mowers or any mower that shreds the cuttings: it kills many insects and leaves the cuttings behind as fertiliser.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

In September or April, broadcast on bare, fine soil and roll lightly. Germinates within 1–3 weeks.

Division

In spring or autumn, dig out a piece of turf with rhizomes and replant it elsewhere.

Common bent: how does it get through the winter?

Hardy to −30 °C.

• The flowering stems die back, but the turf stays largely green in mild winters.
• Fully hardy, to about −30 °C.
• Leave a strip uncut in autumn: caterpillars of grassland butterflies such as the small heath overwinter in the grass.
• Withered panicles covered in frost are a fine sight in an uncut strip in winter.

Diseases and pests

• Rank growth: On rich soil it is crowded out by coarse grasses. Mow twice a year and always remove the cuttings.
• Thatch in the lawn: Bent sometimes forms a spongy layer of dead stems. Light raking in September helps.
• Rust: Orange-brown spots on the leaves in late summer. Harmless; mowing and removing the cuttings is enough.
• Hay fever: Like all grasses, it releases a lot of pollen on the wind in June–July. If it bothers you, mow the patch near the patio before it flowers.
• Runners in the border: The short rhizomes sometimes creep into a border. Cut the edge or weed out the runners.

Through the year

• March: Rake bare patches in a meadow or wildlife lawn.
• April: Sow on bare, fine soil.
• June: Flowering: airy, pinkish-red panicles.
• July: Flowering. Mow the meadow and leave the hay for 2–3 days before removing it.
• August: Late flowers in the uncut strips; the seed ripens.
• September: Second cut and remove the cuttings. Sow.
• October: Leave a strip uncut for overwintering caterpillars.
• December: Rest. Withered, frosted panicles in the uncut strip.

Did you know?

• Agrostis comes from the Greek agros, field; capillaris means ‘hair-like’, after the thin branches of the panicle.
• On old mine spoil heaps in Wales, populations arose that tolerate heavy metals such as lead, zinc and copper. This became a textbook example of rapid evolution in plants.
• It is used in seed mixes for fine lawns and golf greens, where it used to be known by its old name, Agrostis tenuis.