Runner beans can outgrow even quite tall supports, for which reason it is best to pinch out the growth points when they reach the top of the poles, otherwise they just keep on growing. Left unchecked, they will grow into a top tangle. By pinching out the runner beans, you are diverting the plant's energies into making flowers, which become the beans, rather than miles of growth.
Growing Runner Beans really is as easy as that. Usually, they crop prolifically, although yields can be reduced by a poor summer. If it is cool and wet, there will be less flowers and a lack of pollinators, which will reduce yields.
Each plant will yield many beans, which means a short row or teepee will produce quite a lot of beans. To avoid gluts, sow or plant out successively, every fortnight is a good rule of thumb so that the plants fruit at different times. What to do with a glut of runner beans- click here for some ideas.
Runner beans will fruit for a long period right up to the first frosts. In a good summer with a mild autumn, such as 2014, beans were picked up to November.