After a slow start the Runner Beans are a triumph. I didn't sow as many seeds this year, keeping my fingers crossed that the few that I did sow, would survive any onslaughts from slugs, snails and weather. Thankfully they all survived. I did put a pop bottle collar round them when they were planted to deter slug damage, but raising strong plants in the greenhouse helps. In the wild runner beans grow in the Mexican mountains together with dahlias, begonias and lobelias which help bring the bees in to pollinate. Fortunately, bees have learned the trick of opening up the petals to provide an efficient pod-setting service. Unfortunately, pollen beetles also like them which discourages the bees as they sit in the keel of the flower which will then be left unpollinated. The more you pick the more beans will come, but leaving beans on the plant will result in stringy beans and production will stop.
I have sown a late crop of 'Hestia' in pots, they are a dwarf variety, I haven't tried these before, so it will be interesting to see if they produce beans before the frosts, and how many the plants will produce.