People are wondering why French & runner beans go curly.

TopVeg spent a whole summer at Penn State university measuring the angle of the curve - for plots of beans which were grown with different amounts of trace elements!

There does not seem to be much literature available about this, so we asked the Pea Growing Research Organisation why beans grow curly. This is their answer:

“We are not sure if there is any single reason for pod curvature. Some varieties are more prone and although we tend to avoid the worst ones, environmental conditions can be an over-riding factor. Temperatures, particularly big fluctuations between day and night temperatures can be associated but some work in the US seems to think that trace element deficiencies may also be involved.”

Pod curvature in beans is due to several factors:

• temperature - particularly big fluctuations between day and night
• uneven rainfall
• trace element deficiencies
• bean variety -
  White Apollo is a runner bean variety producing straight beans.