Why Are My Orlaya Leaves Curling?

Aphid infestation

Aphids are the most common pest problem on orlaya. The feathery shoot tips and the umbel stems are particularly favoured, and the delicate, finely divided foliage curls and distorts visibly even under light aphid pressure. Willow-carrot aphid and other green aphids are common on umbellifer family plants including orlaya. Heavy infestations distort the developing flower heads as well as the leaves, spoiling the plant's elegant appearance and reducing its value for cutting.

What to do

• Inspect the shoot tips and the undersides of the delicate leaves for aphid colonies. The fine, feathery foliage makes colonies easy to miss at a glance.
• Spray with insecticidal soap every four to five days for two to three weeks, covering the shoot tips and developing umbel stems.
• The flat-topped flowers of orlaya are excellent for beneficial insects including hoverflies, parasitic wasps, and other natural aphid predators: avoid spraying in full flower. Spray in the evening to reduce impact on visiting pollinators.
• Avoid over-feeding with nitrogen-rich fertiliser, which produces soft growth that is especially attractive to aphids.

Drought stress

Despite being a plant of dry Mediterranean scrubland in the wild, orlaya grown in UK gardens, particularly in containers or in free-draining sandy soils, can suffer from drought during warm spells in late spring and summer. The fine leaves wilt and curl relatively quickly when the soil dries out. Container-grown orlaya is particularly at risk since it cannot access deeper soil moisture. Drought stress reduces flower quality and shortens the flowering season.

What to do

• Water orlaya during prolonged dry spells, particularly in the weeks leading up to and during flowering.
• In containers, water when the top 2 cm of compost feel dry. Check daily in warm weather.
• Mulch around border-grown plants to conserve soil moisture and keep the root zone cool.
• Orlaya does not need regular feeding and performs well in lean soil, but adequate moisture is important for good flowering.

Overwatering

Orlaya is a plant of well-drained, even poor soils and does not tolerate persistently waterlogged conditions. In heavy clay or in containers without adequate drainage, the roots deteriorate and the plant declines: the delicate leaves yellow and curl, and the whole plant loses its characteristic freshness. Overwatering is most likely in containers or in borders that have been heavily improved with water-retentive organic matter.

What to do

• Plant orlaya in well-drained, even poor soil. Avoid overly enriched, water-retentive beds for this plant.
• In containers, use a gritty, free-draining compost and ensure good drainage holes.
• Reduce watering during cool or wet periods. Orlaya does not need as much water as most container-grown annuals.

Powdery mildew

Powdery mildew occasionally affects orlaya, particularly later in the season as conditions warm and dry out. The feathery leaves develop a white powdery coating, and affected areas curl and look scorched. It is most common on plants that are under water stress or growing in very dense groups where air circulation is poor.

What to do

• Thin orlaya plants to improve air circulation: aim for 30 cm between plants when thinning autumn or spring sowings.
• Remove and bin affected leaves and stems. Spray remaining healthy growth with a sulphur-based fungicide or potassium bicarbonate solution.
• Ensure adequate watering: drought stress significantly increases susceptibility to powdery mildew.

Transplant stress

Orlaya dislikes root disturbance and is notoriously difficult to transplant successfully. Plants moved from pots or trays frequently wilt, drop their lower leaves, and fail to establish well, with the fine foliage curling and browning at the edges as the root system struggles to recover. This is why direct sowing in the final position is so strongly recommended by experienced growers. Plants that have been transplanted may look stressed for several weeks before either recovering or failing entirely.

What to do

• Sow orlaya direct into its final position in autumn or early spring. Direct-sown plants are far more vigorous than transplants.
• If transplanting is unavoidable, sow into deep root trainers or individual biodegradable pots that can be planted whole without disturbing the roots.
• Water transplants gently but consistently for the first two to three weeks after planting and keep them out of direct sun for the first few days.

Frequently asked questions

Why are my orlaya leaves curling?

Orlaya leaves curl most often from aphid infestation or drought stress. Aphids colonise the feathery shoot tips and young flower stems, causing the delicate foliage to curl and distort. Drought causes the finely divided leaves to wilt and curl rapidly, particularly in containers or in warm settled weather.

Why is my orlaya not flowering?

Orlaya flowers best when sown in autumn or in early spring in a cool position. Plants sown too late in spring or grown in too-rich soil tend to produce leafy growth at the expense of flowers. Orlaya also performs better in lean, well-drained soil than in heavily enriched borders. It will not flower in deep shade.

When should I sow orlaya?

Orlaya germinates best in cool conditions and is best sown direct into the ground in autumn, or in late winter to early spring. It dislikes transplanting, so direct sowing in its final position is strongly recommended. Autumn-sown plants overwinter as small rosettes and begin flowering from late spring.

Does orlaya self-seed?

Yes, orlaya self-seeds freely if the seed heads are allowed to mature and shed. This is one of its most valuable attributes in the cottage or cutting garden. The self-sown seedlings emerge in autumn and provide a fresh cohort of plants without any additional sowing effort.