Perennial ryegrass

How to recognise it

Growth habit

Perennial grass in loose to dense tufts, 10–60 cm tall, without runners.

Leaf

Narrow, 2–6 mm wide, dark green and strikingly glossy underneath; folded in the bud. Short ligule and small auricles at the base of the blade.

Flower

Flat, straight spike of 10–25 cm, from May to August. The spikelets alternate left and right, set edgeways against the stem, and have no awns.

Stem

Smooth, upright or rising at an angle; the base of the shoots is often reddish to purplish.

Roots

A dense network of fine roots, mainly in the top layer of the soil.

Confusion with

Italian ryegrass has awned spikelets, is taller and paler green, and has rolled young leaves. Common couch has creeping rhizomes and spikelets set broadside against the stem. In perennial ryegrass each spikelet has only one glume, on the outer side.

Flowering: May–August · Pruning: June and September

Why grow it?

• Very tough under trampling: ideal for paths, play lawns and places with a lot of foot traffic.
• Food for the caterpillars of butterflies and moths that live on all kinds of grasses.
• The ripe seeds are eaten by sparrows, finches and other seed-eaters.
• Wintering geese like to graze ryegrass pastures in the polders.
• It germinates and grows fast: bare patches in a lawn turn green again within a few weeks.
• An important fodder crop for cattle and horses, and one of the most widely sown grasses in Europe.

Perennial ryegrass: where does it grow best?

• In the wild in grassland, road verges, on dykes, paths, farmyards and other rich, trampled places.
• It likes fertile, moisture-retentive soil: loam, clay or humus-rich sand. On poor, dry soil it slowly disappears.
• Sun to light shade; in deep shade it becomes thin.
• In the garden: in a lawn, play area or path. In a flower meadow it is better to sow little or no ryegrass.

Goes well with

• White clover: Flowers among the grass of a lawn, fixes nitrogen from the air and is loved by bees.
• Yellow rattle: Holds back the grasses and so makes room for flowers in a meadow that is too grassy.
• Daisy: Flowers almost all year round in the short grass of a lawn.
• Common bird’s-foot trefoil: Yellow flowers for bees and a food plant for blue butterflies in a meadow.
• Oxeye daisy: White flowers in May–June that stand out beautifully among the grasses of a hay meadow.

Perennial ryegrass: when and how to plant it?

1. Ryegrass is grown from seed: never take plants or turf from a verge or from the wild. Buy seed or a lawn mixture from a garden centre or seed merchant.
2. Sow from mid-April to late May or from late August to mid-September, when the soil is warm and moist.
3. Rake the soil fine and level, scatter the seed in two directions, about 25–35 g per m² for a lawn, and rake it in lightly.
4. Roll or firm the soil and keep it moist until the grass is 5 cm tall; it germinates within one to two weeks.
5. For a flower-rich meadow, choose a mixture of native grasses and wild flowers with little or no ryegrass, and sow it in September–October.
6. Mow a new lawn for the first time when the grass is 8–10 cm tall, and never shorter than 5 cm.

Care

Water

A ryegrass lawn turns brown in a long drought but greens up again after rain. Watering is usually unnecessary.

Feeding

In a lawn, at most a little compost once a year. In a flower meadow, never: fertiliser makes ryegrass so strong that the flowers disappear.

Mowing

Mow a lawn from April to October at 4–6 cm. Cut a hay meadow twice a year, in late June and September, and remove the cuttings.

Reducing fertility

To turn a ryegrass lawn into a flower meadow, cut it twice a year for a few years and remove the cuttings each time, so the soil becomes poorer.

Yellow rattle

Sow yellow rattle in a grass-rich meadow: this semi-parasite taps into grasses, weakens them and gives flowers more room.

Tip: To turn your lawn into a flower meadow, do not dig it over, but cut it twice a year and remove the cuttings: the soil becomes poorer and ryegrass loses its advantage. Sow yellow rattle to speed things up.

Pruning and mowing

Pruning months: June and September.

When: In a hay meadow in late June and September; mow a lawn from April to October, whenever the grass is 8–10 cm tall.

How:

• Cut a hay meadow with a scythe, brush cutter or bar mower at 5–10 cm.
• Leave the hay for a few days so that seeds can drop and animals can escape, then rake it off.
• Leave a strip or corner uncut each time: caterpillars and other insects overwinter in the grass tussocks.
• Never cut more than a third of the height of a lawn at once.

Caution: Before cutting long grass, check for hedgehogs, toads or young birds, and cut from the centre outwards so that animals can escape.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow in April–May or from late August to mid-September; germinates in 7–14 days. In a meadow it also self-seeds if you let the spikes ripen.

Turf

Pieces of turf can be moved to repair bare patches in a lawn, throughout the growing season in damp weather.

Perennial ryegrass: how does it get through the winter?

Hardy to −25 °C.

• It stays green all winter; in hard frost the leaves discolour a little, but it grows away again in March.
• Hardy to about −25 °C, although long, severe frost without snow cover can cause bare patches.
• Geese, rabbits and hares graze the green leaves in winter.
• Leave a strip of longer grass: caterpillars and beetles overwinter between the tufts.

Diseases and pests

• Dominance: In a flower meadow on rich soil, ryegrass crowds out the flowers. Cut and remove the hay, sow yellow rattle and never feed.
• Rust: Orange powder on the leaves in late summer, especially in dry weather. Simply mow and remove the cuttings; the grass recovers.
• Red thread: Pinkish-red patches with pink threads in the lawn in wet weather. Often a sign of exhausted soil: a little compost and aerating help.
• Hay fever: Its pollen is a major cause of hay fever from May to July. Mow the lawn before it comes into flower if someone at home is sensitive.
• Bare patches: After drought or heavy wear: rake the patch open, oversow and keep moist.

Through the year

• March: The grass starts growing again. Rake moss and thatch out of the lawn.
• April: Sow and repair bare patches. First cut of the lawn.
• May: The spikes appear and flowering starts.
• June: Full flower: lots of pollen in the air. Cut the hay meadow in late June.
• July: The seed ripens. Sparrows and finches feed on it.
• August: Late August: the best time to sow.
• September: Second cut of the hay meadow, remove the cuttings. Repair bare patches.
• October: Last cut of the lawn.
• December: Stays green. Geese and rabbits graze the leaves.

Did you know?

• The Dutch name raaigras is borrowed from the English ray-grass, which is why the Dutch call this species ‘English ryegrass’.
• To the Romans, lolium was darnel, a poisonous relative that grew as a weed in cornfields and that Virgil already called ‘unlucky’. Darnel is often identified with the tares among the wheat in the Bible parable.
• In the 17th century, perennial ryegrass was one of the first grasses to be deliberately sown in England for pasture and hay.