Why have my French beans got curly pods?
Why Do My French Beans Have Curly Pods
Certified GKH Gardening Expert
There's doesn't seem to be a definitive answer for this but some varieties are more prone to curling pods than others, French and runner beans being the most affected. Environmental conditions are the most likely the cause with temperature fluctuations most prevalent. Other factors such as uneven rainfall and trace element deficiencies are also possible.