Why Are My Taro Leaves Curling?

Taro leaf blight

Taro leaf blight (Phytophthora colocasiae) produces water-soaked lesions on the leaf blade and petioles that enlarge rapidly in warm, wet conditions. The lesions collapse the leaf tissue, turning it brown with a purple-brown margin; in humid conditions a cream or white sporulating crust appears. The affected leaf buckles and curls around the dead areas as the healthy tissue contracts around the lesion. In severe cases, the petioles rot and the entire leaf collapses. Taro leaf blight is more common on plants grown in warm, wet greenhouse conditions or in an unusually warm, wet UK summer than on outdoor container plants in typical UK weather.

What to do

• Remove and dispose of (do not compost) affected leaves as soon as lesions appear. Improve air circulation around the plant. Avoid overhead watering and keep foliage dry. If the crown is infected, remove the entire plant. No fungicides are approved for taro leaf blight in UK home gardens.

Dasheen mosaic virus

Dasheen mosaic virus (DsMV) is the most widespread virus of taro worldwide and affects plants brought from infected corms or spread by aphids. On taro, DsMV causes yellow or pale green mosaic streaking along the leaf veins, distortion and curling of the leaf blade (particularly on younger leaves), and reduced plant vigour. Infected plants do not recover. DsMV can be introduced in infected planting material; starting from certified virus-free corms avoids the problem.

What to do

• Remove and destroy infected plants. Control aphids to slow transmission. Use certified or known-healthy corms for new plantings. Do not replant from corms saved from infected plants.

Low humidity and drought

Taro is a marsh and wetland plant in its natural range, adapted to consistently wet conditions. In a UK container in warm weather, the pot can dry out quickly, causing the large leaves to wilt and curl within a few hours. Indoors in winter (for overwintering container plants), low humidity causes the leaf margins to brown and curl. The plant slows dramatically below 15°C and should be kept just barely moist through winter.

What to do

• Water taro very generously in summer; stand the pot in a deep saucer kept filled with water, or grow in a submerged pot at a pond margin. Indoors, place on a gravel tray with water and mist regularly. In winter, reduce watering significantly but do not allow the corm to desiccate completely.

Slugs

Slugs cause large, irregular holes in taro leaves. Severe slug damage distorts young unfurling leaves as they expand around the eaten areas, causing curling and irregular margins rather than smooth, undamaged leaves. Taro's soft, large leaves are attractive to slugs and snails, particularly when plants are young and newly planted out in spring.

What to do

• Protect young plants with copper tape around container edges, or use nematode slug control (Phasmarhabditis hermaphrodita) applied to the soil in spring. Check plants in the evening when slugs are active and remove by hand. Once taro is large and fully established, slug damage is less significant relative to the plant's size.

Frequently asked questions

Why are my taro leaves curling?

Taro (Colocasia esculenta) leaves curl most commonly because of taro leaf blight, dasheen mosaic virus, low humidity, or drought. Taro leaf blight (caused by Phytophthora colocasiae) produces water-soaked lesions on the large, elephant-ear leaves that rapidly expand, turn brown, and cause the leaf tissue to collapse and curl as it dies; the lesions have a purple-brown border and may produce a white or cream crust in humid conditions. Dasheen mosaic virus causes yellow mosaic streaking along the leaf veins and distortion and curling of the leaf blade, particularly on younger leaves. Low humidity in UK indoor conditions causes the leaf edges and tips to curl and brown, as taro is a tropical plant from warm, wet environments. Drought causes the large leaves to wilt and curl rapidly, as taro needs consistently moist or wet conditions at the root.

How do I grow taro in the UK?

Taro (Colocasia esculenta) can be grown in the UK as a container plant or as a temporary garden plant in the warmest summer months. It is not frost-hardy and must be brought indoors before the first frost, or the corm lifted and stored frost-free over winter. Start corms in pots in late March to April in a heated greenhouse or on a warm windowsill; corms need warmth (above 18°C) to sprout and begin growing. Once the risk of frost has passed (late May to June in most of the UK), plants can be moved outside to a warm, sheltered position in full sun or dappled shade. Taro thrives in moist to wet conditions and can be grown as a marginal pond plant with the pot submerged in shallow water; it also grows well in a very generously watered container of rich, moisture-retentive compost. Protect from slugs, which attack the large, soft leaves. Lift the corms in October before the first frost; store in dry compost in a frost-free position and replant the following spring.

What is taro leaf blight and can it be treated?

Taro leaf blight is caused by the oomycete pathogen Phytophthora colocasiae, which infects the leaves and petioles (leaf stalks) of taro. It produces water-soaked lesions that enlarge rapidly, particularly in warm, wet conditions; the lesions turn brown and the surrounding leaf tissue collapses and folds or curls around the dead area. A cream or white crust of sporulating tissue may appear in humid conditions. The lesions typically have a distinct purple-brown margin separating dead tissue from healthy leaf. Taro leaf blight is a serious disease in tropical taro-growing regions; in the UK it is less commonly encountered but can occur on plants grown in warm, wet greenhouse conditions. Remove and destroy affected leaves immediately to reduce spore spread. Improve air circulation, avoid overhead watering, and reduce humidity around the plant. There are no fungicides approved for taro leaf blight in UK home gardens. Plants with severe crown infection should be removed and destroyed.

Is taro the same as cocoyam or eddoe?

Taro (Colocasia esculenta) is the same species as cocoyam, dasheen, and eddo, though different cultivars are known by different names in different parts of the world. Eddoe (or eddo) typically refers to cultivars that produce a smaller central corm with many cormels (side corms) and is common in the Caribbean and West African food tradition. Dasheen refers to cultivars that produce a large central corm with fewer cormels and is used more in the Pacific Island and South Asian traditions. Cocoyam is a broader term used in West Africa for both Colocasia and the unrelated but similar Xanthosoma (which includes malanga, yautia, and taro blanc). All are edible, all are closely related, and all share the same cultural requirements and susceptibility to the same pests and diseases in UK cultivation.