Runner beans are probably one of the easiest things to grow and so every one no matter how they plant them (almost) always has a successful crop so what ever they do, works and they will swear that it is the best way.
6 - 8 inches apart, planted singly in a double row 18" between, is my favourite way.
Wind is the big problem once they have grown and are full of produce. They are heavy. If the ground is wet and slushy at the same time it can get messy.
On windy sites, perhaps making a frame with timber then fastening canes to the frame, as I have seen, will help them to stay upright. Wigwams are going to be stronger than two rows tied together, you could call it all round support.
In the past I have sown climbing french beans, dwarf french beans and runner beans together without any problem at all, other than getting more beans than I know what to do with.
The only tip I have for runner beans is to pick them all young, don't let them get long and stringy, even if you do not want them all, new ones will come. People just 'pick enough for a meal' and then have a load growing too big, I would rather give some away than do that. The french beans do not seem to get stringy.
