Plant problems

Why Are My Garrya Leaves Curling?

Q: Why are my garrya leaves curling?

Garrya (principally Garrya elliptica, the silk tassel bush) leaves curl most commonly in the UK because of wind scorch, frost damage to young growth, drought stress, or scale insects on plants in sheltered or pot-grown conditions. Garrya is a robust, wind-hardy evergreen shrub from California and Oregon with thick, waxy, dark grey-green leaves and distinctive long, drooping grey-green catkins in January and February; it is one of the most reliable evergreen shrubs for north-facing walls in UK gardens. The thick, waxy leaves with their naturally wavy or undulate margins are inherently resistant to leaf damage, but the margins and tips can curl and brown when the plant is exposed to very cold, dry east or north-east winds in winter, when young spring growth is caught by a late frost, or when the plant is severely drought-stressed. Scale insects (Pulvinaria floccifera and other species) can build up on the stems and leaf undersides of garrya, particularly on plants growing against sheltered, warm walls or in large containers; the leaves yellow and curl as scale feeding reduces the plant's vigour.

Q: Why does garrya look so bad in spring?

Garrya often looks its worst in April and May, after the winter catkins have finished and before the new season's growth has flushed out fully; this temporary shabby appearance is normal and not a sign of a problem. The old leaves from the previous year may look dull, grey-green, slightly tatty, and the spent catkin stalks can persist on the plant and look untidy; at the same time, the new flush of growth has not yet expanded to give the plant its full summer appearance. On plants that have experienced a cold or windy winter, the old leaf tips and margins may be brown and scorched, making the plant look particularly neglected in early spring. The solution is simply patience: garrya flushes out vigorously in May and June, producing new, glossy, fresh leaves that restore the plant's good looks quickly. If the plant genuinely appears unhealthy in spring (with peeling bark, dying stems, or leaves that are completely dead rather than just shabby), this is a sign of a more serious problem; check for physical damage to the main stems, waterlogging of the root zone, or scale insect infestation on the stems. On north-facing walls in cold UK gardens, garrya that has endured a particularly harsh winter may drop some old leaves in spring as new growth begins; this is natural autumn-type leaf drop delayed by the cool conditions and is not a cause for concern.

Q: How do I grow garrya in the UK?

Garrya elliptica is one of the most versatile evergreen shrubs for UK gardens because it tolerates conditions that most ornamental shrubs reject: north-facing or east-facing walls, exposure, urban pollution, and coastal conditions. The key requirements are: a sheltered position (it tolerates sun or shade but needs shelter from very cold, desiccating east winds, which scorch the leaves; a north wall provides both the shelter and the reflected warmth); well-drained soil (garrya comes from the drier parts of California and does not tolerate waterlogged roots); and reasonable fertility. Plant in autumn or spring in well-drained soil with added organic matter; train the young plant against the wall or fence by tying in the main stems; garrya can also be grown as a freestanding shrub in a sheltered position. The most important pruning tip for garrya: prune immediately after the catkins have finished (typically late February to March) if pruning is needed; never prune in autumn because this removes the developing catkins for the following winter. To maximise catkin length, choose a male plant (male garrya have longer, more decorative catkins); female plants have shorter, less impressive catkins but produce berries if pollinated by a male. 'James Roof' is a particularly popular male selection with exceptionally long catkins to 30cm or more. Garrya is available from most UK garden centres and can be grown from semi-ripe cuttings taken in summer.

Q: How do I control scale insects on garrya?

Scale insects on garrya are most likely to occur on plants growing in sheltered conditions against warm south or west walls, or in large pots or containers, where the warm, protected environment allows scale populations to build without the natural control provided by cold and wet UK winters. The cottony cushion scale (Pulvinaria floccifera) produces conspicuous white, woolly egg masses attached to the stems and leaf undersides in spring and early summer; the flattened, brown adult scales cluster on the stems throughout the year. To control: in late spring or early summer when the newly hatched crawlers (mobile juvenile scale insects) are present, apply an insecticidal soap or mineral oil spray to all plant surfaces; the crawlers are the most vulnerable stage and the treatment must coincide with their emergence. Apply the spray thoroughly to all stem surfaces and leaf undersides where scale clusters. Introduce Metaphycus helvolus (a parasitoid wasp that parasitises soft scale) for biological control in sheltered wall conditions where the parasitoid can survive. On established garrya growing in open garden conditions, scale rarely reaches damaging levels; the UK climate, natural predators, and the plant's vigour keep scale populations in check.

Garrya elliptica (silk tassel bush) is a robust, wind-hardy evergreen from California prized in UK gardens for its spectacular long, drooping catkins in January and February and its tolerance of north-facing walls where few other attractive shrubs thrive. The thick, waxy, naturally wavy-margined leaves rarely suffer significant damage, but cold east wind scorch, late spring frost on new growth, or scale insects in sheltered positions can cause curling and browning.

Wind scorch

Cold, desiccating east or north-east winds in winter can scorch the leaf margins of garrya, causing the tips and edges to brown and curl inward even on a plant that is nominally sheltered. The damage typically appears in February or March after a prolonged cold and windy spell; the scorched leaf margins and tips remain brown and curled through spring until new growth covers them. Garrya's natural habitat is sheltered California coastal scrub, where winds are primarily from the west and are moist rather than desiccating; the cold, dry east winds that arrive in the UK from continental Europe in some winters are outside its natural experience.

What to do

Ensure the plant is sheltered from cold east and north-east winds; a wall, fence, or windbreak on the east side is the most effective protection. On newly planted garrya, protect from east wind with a temporary windbreak of windbreak netting or fleece in the first two winters while the plant establishes. Once established, garrya tolerates significant wind from other directions; it is the cold east wind, not wind per se, that causes the most damage. The scorched leaves will be covered by new growth in May and June; no immediate action is needed beyond providing shelter.

Frost damage

The young growth of garrya in spring (April to May) is less hardy than the established leaves and can be caught and damaged by late frosts; damaged young leaves turn brown at the tips, curl, and may fail to expand fully. Established garrya leaves are hardy to at least -10°C; the tender young spring growth is more vulnerable to temperatures below -2 to -3°C. Frost damage to new growth is most likely on plants in frost pockets or in garden positions where cold air drains and collects.

What to do

Avoid planting in frost pockets (low-lying areas where cold air collects). A wall-grown garrya benefits from the thermal mass of the wall, which reduces frost penetration around the plant. If a late frost is forecast when new growth is expanding, cover with a layer of horticultural fleece overnight. Frost-damaged new growth recovers as the season progresses; remove any brown, dead growing tips to encourage healthy replacement growth.

Scale insects

Scale insects, particularly soft scale (Coccus hesperidum) and cottony cushion scale (Pulvinaria floccifera), can infest garrya growing against sheltered, warm walls or in large containers where the protected microclimate allows populations to build without the usual winter checks. Infested stems appear encrusted with flat, brown or white, waxy bumps; heavily infested leaves yellow, curl, and drop prematurely as the scale drains sap; honeydew and sooty mould accumulate on the stems and upper leaf surfaces.

What to do

Scrub off scale clusters from stems with a stiff brush and insecticidal soap. Apply insecticidal soap or horticultural oil spray to all stem surfaces and leaf undersides in late spring when the crawler stage is most vulnerable. Introduce Metaphycus helvolus for biological control. Improve air circulation around the plant to reduce the sheltered conditions that favour scale build-up. On plants in open, exposed positions, scale rarely requires treatment.

Drought stress

Established garrya is more drought-tolerant than many UK garden shrubs because it comes from the seasonally dry climate of California, where summers are very dry; it copes well with UK drought conditions once established. However, newly planted garrya (in the first two years) needs regular watering through dry spells to establish; drought stress in a new plant causes the leaf margins to brown and curl. Container-grown garrya requires more regular watering than ground-planted specimens.

What to do

Water newly planted garrya regularly in the first two summers during dry spells; once established, irrigation is rarely needed. Apply a mulch of composted bark around the root zone to conserve moisture in the first two years. Container-grown garrya needs regular watering throughout summer; ensure the pot has adequate drainage to prevent waterlogging, which is more damaging than drought.

Frequently asked questions

Why are my garrya leaves curling?

Garrya (Garrya elliptica) leaves curl most commonly because of cold east wind scorch (browning and curling of leaf tips and margins in winter and early spring), late frost damage to new spring growth, scale insects on sheltered wall-grown plants, or drought stress in newly planted specimens. Garrya is a very robust plant with naturally wavy leaf margins; most leaf problems are temporary and the plant recovers with the spring flush of new growth.

Why does garrya look so bad in spring?

Garrya often looks its worst in April and May after the catkins finish and before the new growth flushes out; old leaves from the previous year may look dull and tatty, and spent catkin stalks persist. This is completely normal. By June, a flush of new, glossy leaves transforms the plant. If the stems are dead or the main framework is damaged, investigate for waterlogging, root rot, or severe wind damage.

How do I grow garrya in the UK?

Garrya thrives in well-drained soil against a sheltered north, east, south, or west wall; it is one of the best shrubs for north-facing aspects. Shelter from cold east winds is more important than sun. Plant in autumn or spring. Prune only after catkins finish (late February to March); never prune in autumn. 'James Roof' is the best male selection for catkin length (up to 30cm).

How do I control scale insects on garrya?

Apply insecticidal soap or horticultural oil spray to all stem surfaces and leaf undersides in late spring when the newly hatched crawler stage is most vulnerable. Scrub off established scale clusters with a stiff brush. Introduce Metaphycus helvolus for biological control. In open, exposed garden positions, scale rarely requires active treatment; it mainly affects sheltered wall specimens.