Broad Bean plants can be very floppy and I think they benefit from some support. If left to their own devices they often get very tangled, and sometimes fall flat on the ground, where they can become wet and start to rot. Another reason why they are best kept upright is to give bees better access to the flowers. I have tried various support systems over the years, but I have concluded that the best method is to stake each plant separately. This of course is only really practical if you have a small number of plants. In this raised bed in my garden I have a total of 20 plants - 5 each of 4 different varieties - and this week I have staked them. They were getting too tall for the net which has been covering them since they were first planted out.
Each plant has its own 5-foot bamboo cane, to which it is lightly tied with soft green string.
Some varieties of Broad Bean grow quite tall, so longer canes might be necessary for these, though of course most people pinch out the tops of the plants once pods begin to set, because this helps to reduce Blackfly infestation.
The net which had been protecting the Broad Beans has now been re-deployed to the Parsnip bed, which has gone from this...
Up at the Courtmoor Avenue plot I have used the same staking technique for my Broad Beans, except that the canes have been substituted with some rather rustic sticks taken from the apple-tree prunings.
I can see that the apple-trees are going to be a very valuable source of materials for one thing and another. This makes me happy, because it is good to work in harmony with Nature whenever possible and little bits of wood will be much better for the planet than plastic or even bamboo imported from the other side of the world.