Diagnose by symptom
Curled, distorted leaves
Rolled, curled or distorted leaves are usually sucking pests or leaf-curl fungus. Check:
Diseases
Pests
Aphids
Small (1–3 mm) soft-bodied insects, green, black or pink, feeding in clusters on young shoots and the underside of leave…
PestLeaf-roller moths (tortricids)
The caterpillars roll, fold and glue leaves together with a webbing of silk threads, creating shelters in which they fee…
PestThrips
Very small (1–2 mm), slender, elongated insects with fringed wings, coloured yellow, brown or black; the larvae are pale…
Frequently asked questions
Why are my leaves curling?
Leaf curling is a response to several triggers: sap-sucking pests (aphids, leaf-roller moths), water stress and heat (the plant rolls its leaves to reduce evaporation), and sometimes disease or herbicide damage. Unroll a curled leaf and look inside – aphids or leaf-roller caterpillars often hide there. Also assess soil moisture and temperature.
Do curled leaves mean pests?
Often yes – aphids feeding on young leaves cause crinkling and curling, and leaf-roller moths roll the leaf and bind it with silk while hiding inside. Look for aphids, sticky honeydew, or caterpillars in the curled leaves. If no pests are present, the cause is more likely water stress, heat, or chemical damage.
Do heat and lack of water cause leaf curling?
Yes – in heat and with insufficient water the plant rolls or folds its leaves to reduce the evaporating surface and limit moisture loss. Such leaves usually flatten out again in the evening or after watering, provided the roots are healthy. Water evenly and mulch the soil to reduce the moisture swings that cause stress.