This year I have finally developed a sure method to build a stable frame for the runner beans - which I have yet to plant this season, but there's plenty of time!
In my early years of allotmenting, my traditional bamboo bean poles always blew over, or at least became very wonky within very few weeks of the summer. With this method, the frame is much more stable.
I find 7 foot (2 m) poles about the right size, using thirty all together, and a good deal of green garden twine to tie them all together. My swiss army knife comes in handy! This task definitely brings out my inner girl guide... All that practice putting together washing up tripods finally paying off!
Start by laying out a pair of poles for each end and one for the middle, with a cross pole at the top and two across the middle between each pair (see picture, left). The whole frame ( allowing for overlaps) is about 12 foot long.
Bamboo is good, as it grows in roughly one foot sections, and so the cross poles helpfully indicate the distance to allow between supporting uprights, and, eventually, the bean plants. (I usually put in a double row of beans round each upward pole.) Add the uprights in pairs, reserving 2 poles to use as supports for the ends.
It's useful to tie each pair of uprights to the top cross pole, but only about a third to the middle ones. Use good knots and secure girl guide methods!
Lastly, insert the last two poles at an angle leaning into either end of the frame and tie them in securely. I like to plant nasturtiums or train sweetpeas up these end poles.
The last pair of poles add stability to the frame, and will stop it bending to every breeze, although if there are high winds later in the season, I sometimes need to attach guy ropes and pegs (borrowed from our tent) for additional support.
With this size frame and with a double row of bean plants each side ( about 40 plants altogether) I usually grow sufficient runners for my family of four to eat three or four times weekly through August and September, and give surplus to neighbours and friends now and then.