How deep do you plant runner beans?
Should I stop runner bean plants when they reach the top of the poles?
Frankly, I would just leave them be. They will eventually twine around other parts of the plant or you can even help get them started. While trimming may stunt growth, it could encourage other problems, such as disease. They're only going to grow so much anyway.
I have bunches of small wet growths on the roots and root hairs of the runner beans and potatoes I have just dug up from my garden. Are these a disease or insect? Will they affect the rest of my soil, and if so, how do I get rid of them?
I suggest you take a sample to your local agricultural extension office for identification. Without being able to see and feel, one would be hard pressed for accurate answers.
Is there any reason why I cannot grow runner beans in the greenhouse in February or March?
No reason at all. As long as the temps are right and there is enough light, you can do this.
I have just bought a home with a runner bean vine in the garden. The vine is no longer producing and is quite messy. I would like to continue growing beans. Do I cut the vine down to near soil level and hope it grows back, do I leave it to fully wither, or do I pull it out and plant fresh?
If the vine has finished, it is better to pull it up and start another plant, as these will not regrow.
I have started gardening this year for the first time. Our garden in mainly limited to patio, so I have had to use growbags and pots to create space. My runner beans are all beginning to have yellow leaves. They are setting beans and producing flowers and up until a couple of weeks ago, they looked really healthy. I have been feeding with an organic worm-cast feed every week. Any advice appreciated. I have read that nitrogen deficiency may be the problem?
Many thanks for your advice, I have been feeding with an organic tomato feed, improved drainage and they are bouncing back nicely!
Yes, yellow beans are typically a sign of poor soil conditions or poor watering conditions. Check your soil and make sure you aren't over- or underwatering. This article will give you some tips on how to correct your soil if that's the issue:
https://www.gardeningknowhow.com/edible/vegetables/beans/yellow-leaves-on-beans.htm
And this article will give you some additional tips on growing beans:
https://www.gardeningknowhow.com/edible/vegetables/beans/tips-for-growing-beans.htm
Why have I no flowers on runner beans?
This is likely due to excess nitrogen in the soil.
Here are some links that will help you.
https://www.gardeningknowhow.com/edible/vegetables/beans/get-bean-plants-to-bloom.htm
https://www.gardeningknowhow.com/ornamental/vines/scarlet-runner-bean/growing-scarlet-runner-beans.htm