Plant problems

Why Are My Lagurus Leaves Curling?

Q: Where has lagurus ovatus naturalised in the UK?

Lagurus ovatus (hare's-tail grass) is not native to the UK but has naturalised at a small number of sites in south-west England and the Channel Islands, primarily in open, sandy, coastal habitats; it is also occasionally recorded as a casual introduction at other southern England sites, typically near coastal paths, beaches, and disturbed sandy ground. Established naturalised sites in the UK: Isles of Scilly: Lagurus ovatus is well-established and naturalised in the Isles of Scilly, where it grows on coastal paths, sandy open ground, and the margins of cultivated land; the mild, frost-free climate of the Scilly Isles is the closest equivalent to a Mediterranean coastal climate available in the UK and provides ideal conditions for a permanent self-sustaining Lagurus population. Channel Islands: Lagurus ovatus is also naturalised and locally common in the Channel Islands (particularly Jersey and Guernsey), where the warm, mild, Mediterranean-influenced climate allows it to self-seed and persist as a component of the coastal sandy and disturbed-ground flora. South-west England: occasional naturalised or persistent populations have been recorded on coastal paths, sandy ground, and disturbed coastal sites in Cornwall and Devon; these are less well-established and more temporary than the Scilly Isles and Channel Islands populations. UK casual occurrences: Lagurus is occasionally recorded as a casual introduction at various southern England sites where it has self-seeded from garden plantings or arrived with imported sand or coastal material; these casual occurrences are temporary and do not persist long. UK conservation status: Lagurus ovatus is not a native UK species and is not protected; casual and naturalised populations do not raise conservation concerns; it is not invasive in UK conditions.

Q: Why are lagurus flower heads turning yellow or brown?

The flower heads of Lagurus ovatus are the primary ornamental feature of the plant and their loss of the characteristic soft, silky, creamy-white or pale green freshness is a frequent concern for UK gardeners growing the plant for cut or dried flower production. The most common causes of head discolouration and deterioration are: Natural ripening: the heads of Lagurus pass through distinct developmental stages from the first emergence of the fluffy, densely hairy, soft green head through the fully developed, bright green, soft, silky stage (the optimal harvest moment for fresh cut or drying) to the natural yellowing and browning of the head as the seeds ripen; this natural ripening progression is entirely normal and the browning and yellowing of the heads in August to September is the completion of the annual lifecycle; harvest before the onset of browning if clean, creamy-white dried heads are required. Botrytis grey mould: in warm, humid, wet UK summer conditions, Botrytis cinerea can attack the dense, soft, hairy heads of Lagurus; the mould appears as a grey, fluffy, mould growth on the surface of the head, causing rapid deterioration of the head's appearance; Botrytis is promoted by warm, humid, still air around the plant; improve ventilation around the plants; avoid wetting the heads when watering; harvest heads before prolonged wet weather in July and August. Premature ripening from drought: drought stress in July and August (from a very thin, freely draining substrate or a container that has dried out) can cause the heads to begin yellowing and ripening earlier than normal; maintain consistently moist (but not waterlogged) root zone conditions through the peak flowering and head development period to prevent premature ripening. Aphid and insect attack: aphids occasionally infest the developing heads of Lagurus and cause yellowing, distortion, and stickiness; control with an organic soap spray or by encouraging natural predators.

Lagurus ovatus (hare's-tail grass, bunny tails) is a Mediterranean annual grass widely grown in UK gardens and cutting gardens for its extraordinarily soft, fluffy, ovoid, densely hairy flower heads, one of the most popular fresh-cut and dried flower ornamental grasses available to UK gardeners. Leaves curl from drought in the root zone, overcrowding from dense sowing or competing adjacent plants, or fungal Botrytis grey mould on the soft, hairy heads and leaves in warm, humid conditions.

Drought in the root zone

Moderate drought stress in a container or very sandy bed in July and August detracts significantly from the plant's appearance, causing the soft, hairy leaves to roll inward and the leaf tips to yellow and brown; the characteristic soft, lush, grey-green leaf appearance is lost. The fluffy heads are somewhat more drought-resistant than the soft leaves but premature head ripening can also result from a persistently dry root zone during peak flowering.

What to do

Water regularly through the growing season, especially in July and August; keep the root zone consistently moist but not waterlogged; drought stress during head development in particular detracts from both the fresh-cut and dried flower quality of the heads; in a container, check daily in hot weather and water before the compost dries out completely; a light mulch of grit around the base of border plants helps retain moisture in a dry summer without causing waterlogging.

Overcrowding and competition

Sown too densely, lagurus plants produce taller, spindlier, narrower-leaved growth prone to leaf yellowing, curl, and lodging; adjacent plants taller than lagurus shade out the lower leaves, causing basal leaf yellowing, curl, and die-back. The soft, relatively small plant (30 to 60 cm) needs adequate space to develop its characteristic soft, bushy, well-branched form with multiple flower heads.

What to do

Thin direct-sown plants to 20 to 25 cm spacing as early as possible; avoid sowing too densely (a common mistake with the easily available seed); plant module-grown plants at the same minimum spacing; do not allow adjacent annual flowers to shade or crowd out the lagurus plants; a position where lagurus is among the taller plants in the bed, or where it has open space around it, gives the best, most bushy, best-headed results.

Botrytis grey mould

The dense, soft, hairy heads of lagurus provide an ideal moist environment for Botrytis cinerea spore germination in warm, humid, wet UK summer conditions; affected heads develop a grey, fluffy mould growth that destroys the ornamental quality of the head rapidly. The soft, hairy leaves are also susceptible in persistently humid, poorly ventilated conditions. Botrytis is the primary fungal threat to lagurus in a typical UK summer.

What to do

Harvest the heads before the onset of prolonged wet, warm, humid weather in July and August; the optimal harvest time for both fresh-cut and dried flower use is when the head is fully developed, at its softest, most densely hairy, fresh-green or just-emerging stage; this early harvest both gives the best quality dried material and prevents Botrytis attacking the ripe, damp heads. Improve air circulation around the plants: thin sowing, removing adjacent crowding plants, and choosing an open, well-ventilated position all reduce Botrytis pressure. Avoid wetting the heads when watering; water at the base of the plant.

Frequently asked questions

Why are my lagurus leaves curling?

Lagurus leaves curl most commonly because of drought in the root zone (soft hairy leaves roll and tip-yellow in dry spells in July and August; water regularly to keep root zone consistently moist but not waterlogged; check containers daily in hot weather; light grit mulch in borders retains moisture), overcrowding and competition (densely sown plants produce spindly narrow-leaved growth prone to curl and lodging; shading from adjacent taller plants causes basal leaf yellowing and curl; thin to 20 to 25 cm spacing; give plants open space around them), or Botrytis grey mould (grey fluffy mould on the dense soft hairy heads in warm humid wet UK summers; harvest heads at the fresh fully developed green stage before prolonged wet weather; improve air circulation by thinning; avoid wetting the heads when watering). Early harvest for drying prevents both Botrytis damage and premature ripening browning.

How do I grow lagurus ovatus in a UK garden?

Sow directly in prepared well-drained seedbed in late March to April in warm sunny position; or in modules under glass in March, plant out after last frost; surface sow; cover lightly; germination best above 12 to 15°C; thin or plant at 20 to 25 cm spacing; do not sow too densely. Warm, sheltered, sunny to lightly shaded south or west-facing position; does well against a warm wall; moderately fertile open-textured border soil in full sun; more tolerant of soil types than most Mediterranean annual grasses; no need for exceptionally lean or dry soil. Water regularly through the growing season; consistently moist root zone in July to August. Harvest heads as soon as fully developed at softest most densely hairy stage for fresh cut or drying; hang in small bunches upside-down in warm airy dry position; dries to creamy-white or pale straw retaining silky fluffy texture for months.

Where has lagurus ovatus naturalised in the UK?

Not UK native but naturalised at a small number of coastal sites. Isles of Scilly: well established and naturalised on coastal paths, sandy open ground, and margins of cultivated land; mild frost-free climate closest to Mediterranean conditions in the UK. Channel Islands: naturalised and locally common in Jersey and Guernsey; warm mild Mediterranean-influenced climate allows persistent self-seeding. South-west England: occasional naturalised or persistent populations on coastal paths and disturbed coastal sites in Cornwall and Devon; less well-established than Scilly and Channel Islands populations. Casual occurrences throughout southern England from garden self-seedings or imported sand material; temporary and non-persistent. Not a native UK species; not protected; not invasive in UK conditions.

Why are lagurus flower heads turning yellow or brown?

Natural ripening: heads progress from soft green through creamy-white to yellowing and browning as seeds ripen in August to September; harvest at the fully developed soft green or just-emerging stage to get the cleanest creamy-white dried heads before browning begins. Botrytis grey mould: grey fluffy mould in warm humid wet conditions; harvest before prolonged wet weather; improve ventilation; avoid wetting heads. Premature ripening from drought: drought in July to August causes earlier-than-normal head yellowing and ripening; maintain consistently moist root zone through peak flowering. Aphid attack: occasional; yellowing and distortion; control with organic soap spray or encourage natural predators.