Why Are My Blueberry Leaves Curling Inward?

Blueberry leaves roll or curl inward as a protective response to stress — it reduces the leaf surface area exposed to sun or drying wind and slows water loss. Knowing whether the curl is a short-term physical response or a sign of pest feeding or disease determines whether you need to act or simply wait. The clues are in which leaves are curling, whether there is distortion, and what the underside of the leaf looks like.

Heat and drought rolling

During hot, sunny or windy weather, blueberry leaves will naturally curl along their length into a narrow tube to conserve moisture. This is a temporary physiological response, not a disease or pest. The leaves will uncurl in the evening or after watering, and there will be no discolouration, distortion or insects visible. If this is the cause, the plant simply needs more consistent moisture and thick mulch. Plants in containers or light sandy soil are most susceptible. The fix is deep, regular watering and a generous mulch layer to insulate the root zone.

Blueberry tip midge

Blueberry tip midge larvae feed on new growth at the shoot tips, and the plant responds by rolling or puckering the young leaves tightly around the feeding site. Unlike drought curl, this distortion is fixed — the leaves do not flatten out in the evening, and they often remain twisted or stunted as they mature. If you look carefully inside the tightly rolled tip, you may find tiny orange or cream larvae. Affected shoot tips should be removed and destroyed. Encourage natural predators and avoid insecticides that disrupt beneficial insects during flowering.

Aphid colonies

Large colonies of blueberry aphids feeding on young leaves cause the leaf edges to curl downward and inward around the colony, which both shelters the insects and traps them against the food source. Turn the leaf over: if you see dense clusters of small pale or green insects, aphids are the cause. A strong blast of water removes many of them, and insecticidal soap applied to the undersides of leaves is effective for larger infestations. Do not overfeed with nitrogen, which produces the soft, sappy growth aphids prefer.

Virus infection

Persistent leaf curling or rolling that is accompanied by mottled, mosaic-patterned or dwarfed leaves across multiple parts of the plant may indicate a viral infection such as blueberry leaf mottle virus or blueberry shock virus. There is no cure for viral infections — the plant should be removed and destroyed to prevent spread to healthy bushes. Always buy certified virus-free stock and control aphids, which are the primary vectors.

Normal young leaf behaviour

Very young leaves emerging from the bud are often slightly cupped or rolled as they unfurl. This is completely normal and resolves as the leaf expands. If only the newest, smallest leaves look rolled while the mature foliage is flat and healthy, no action is needed.