Why are your runner beans curling?

Runner beans may curl due to several factors, including environmental stress, such as inconsistent watering or extreme temperatures. Pest infestations, particularly aphids, can also cause the leaves to curl as they feed on the plant's sap. Additionally, nutrient deficiencies, particularly in nitrogen or potassium, can lead to abnormal leaf growth. Ensuring proper care, including adequate water, nutrients, and pest management, can help prevent curling.