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Having trouble with my runners ; they are a white self pollinating variety
growing extremely well with masses of flowers. These unfortunately are not
setting and are falling off. The house is well ventillated at all times with
doors and vents open fully. the roots are kept moist not sopping and other
plants are also growing well. when I have similar problems outside I watered
with a strong lime mix which helped ; not to keen to use this method in the
house.

Runner beans are self-fertile but I've ever heard of self-pollinating
ones. Usually they need bees to fertilise the flowers, which are heavy
enough to open the flowers and get inside. Not many bees go inside a GH;
and anyway it will be too hot for the beans in there. Best grown outside
imho, though if you are in an area with late frosts it's useful to start
the beans in pots in the GH and plant them out in the 2nd week of June.

Janet.