Why Are My Mango Leaves Curling?

Powdery mildew

Mango powdery mildew (Oidium mangiferae) is the most common disease of mango in the UK and is particularly damaging because it attacks the young leaf flush before the tissue has fully hardened. The fresh, reddish-bronze young leaves curl, twist, and become coated in a white or greyish powdery bloom as the fungus colonises them. Affected leaves fail to expand to their full size and may remain permanently distorted. The same fungus attacks flower spikes, causing the flowers and young fruitlets to drop. Mango powdery mildew is worst in conditions of warm days (20 to 25°C) and cool nights (10 to 15°C) with moderate humidity, conditions common in UK greenhouses in spring and autumn.

What to do

• Apply a sulphur-based fungicide spray or potassium bicarbonate solution to new growth at the first sign of mildew and repeat every 10 to 14 days through the vulnerable flush period. Improve air circulation. Avoid overhead watering. Remove and dispose of the most affected leaves. Do not compost infected material.

Anthracnose

Anthracnose (Colletotrichum gloeosporioides) causes dark brown to black lesions on mango leaves, typically starting at the tips or margins and spreading inward. The lesions have an irregular, water-soaked border; as the affected tissue dies, it curls and wrinkles. In humid conditions, salmon-coloured spore masses may appear in the lesions. Anthracnose also attacks flowers and young fruits and is the primary reason for post-harvest fruit rotting on mango; it can lay dormant on green fruit and activate as the fruit ripens.

What to do

• Remove and destroy affected leaves. Improve air circulation and avoid wetting the foliage. A copper-based fungicide spray applied preventively during wet conditions can slow spread. Ensure good sanitation; remove fallen leaves from the growing area promptly.

Cold damage

Mango is a tropical tree with no frost tolerance. Temperatures below 10°C cause the leaves to pale, yellow at the margins, and curl; temperatures below 5°C cause lasting damage to leaves, growing tips, and young wood. UK winter conditions in unheated conservatories (which can drop to 5 to 8°C overnight) are right at the edge of what mango can tolerate. A cool period of 8 to 10°C for 6 to 8 weeks is actually beneficial for flowering induction in mango, but the temperature must not drop below 5°C and should be managed deliberately rather than accidentally.

What to do

• Maintain temperatures above 10°C in winter and above 18°C for active growth. Reduce watering significantly in winter. Protect from frost at all times. Cold-damaged leaves do not recover; once temperatures rise, the tree will produce new growth if the roots and main stem were not damaged.

Red spider mite

Red spider mite (Tetranychus urticae) can colonise mango leaves in warm, dry greenhouse conditions, producing pale stippling on the upper leaf surface and fine webbing on the undersides. The leaves yellow and curl downward as the infestation progresses. Spider mite on mango is less prominent than powdery mildew but becomes significant in a very dry summer or in a poorly ventilated greenhouse where humidity drops.

What to do

• Increase humidity around the plant by misting the foliage (particularly leaf undersides) and standing the pot on a gravel tray with water. Introduce Phytoseiulus persimilis predatory mites for biological control. Treat with insecticidal soap or a plant-safe miticide if the infestation is severe before biological controls can establish.

Frequently asked questions

Why are my mango leaves curling?

Mango (Mangifera indica) leaves curl most commonly because of powdery mildew (Oidium mangiferae), anthracnose (Colletotrichum gloeosporioides), or cold temperatures. Mango powdery mildew is distinctive because it attacks the young leaf flush: the freshly opening leaves (which are characteristically red-pink to bronze before they mature to dark green) curl, twist, and become coated in a white powdery bloom as the fungus colonises them before the leaf tissue has fully hardened. Affected leaves become distorted and fail to expand to their full size. Anthracnose causes dark brown to black lesions on the leaf margins and surface; affected tissue dies and curls as it dries. Cold temperatures below 10°C cause mango leaves to yellow, droop, and curl as the tropical tree enters cold stress; temperatures below 5°C cause lasting damage to leaves and growing tips.

Can I grow a mango tree in the UK?

Mango (Mangifera indica) can be grown in the UK as a heated greenhouse or large conservatory plant, though producing fruit in UK conditions requires sustained high temperatures, high light, and specific management to induce flowering. Mango trees are commonly grown from the stone of a shop-bought fruit by removing the husk and planting the inner seed at 20 to 25°C; germination is unreliable and seed-grown trees may take many years to fruit, if ever. Grafted or air-layered trees from specialist nurseries fruit sooner and come true to variety. Mango requires temperatures above 18°C for active growth, full sun, excellent drainage, and a dry period in winter to initiate flowering. Hand-pollination is required for fruit set indoors. Mango trees grow very large if unpruned; in a UK greenhouse they are best kept compact by pruning after fruiting.

Why are my mango's new leaves curling and white?

Curling and white powder on newly opening mango leaves is almost certainly mango powdery mildew (Oidium mangiferae), which is specifically adapted to attacking the young leaf flush and flower spikes of mango. Unlike the powdery mildew of many other plants (which typically appears on mature leaves), mango powdery mildew colonises the leaf before the tissue has fully hardened, causing the young leaf to curl, twist, and fail to expand normally while coating it in a white or grey powdery bloom. Affected leaves may become permanently distorted even after the visible mildew is controlled. Mango powdery mildew is worst in conditions of warm days, cool nights, and moderate humidity, which can occur in UK greenhouses in spring and autumn. Treat with a sulphur-based or potassium bicarbonate fungicide spray applied to new growth at the first sign of infection; repeat every 10 to 14 days through the vulnerable flush period.

Why are the tips of my mango leaves turning brown?

Brown leaf tips on mango in the UK are most commonly caused by low humidity, salt accumulation in the compost from over-fertilising, or fluoride or chlorine sensitivity. Mango is from a humid tropical environment and in the low-humidity conditions of a UK home or conservatory in winter, the leaf tips dry, turn brown, and may curl. Salt accumulation from excessive fertiliser application builds up in the compost and draws water out of the roots osmotically, causing tip burn as the extremities of the leaves are the first to suffer. Flush the compost thoroughly with water periodically to leach out accumulated salts. Chlorine sensitivity can also cause tip browning; use rainwater or allow tap water to stand overnight before watering. Anthracnose can also cause dark brown to black spots that progress from the tips inward; this is accompanied by clearly defined lesions rather than the even browning of environmental stress.