[nannytroll]

The vines are up and over the top of the stakes, masses of flowers, but just a few beans. The flowers seem to be falling off without being fertilized. Another thread has commented on the lack of cabbage white butterflies, and I've only seen half a dozen here. I wonder if there could be a lack of pollinating insects too?

[JayG]

Runner bean flowers have to be both visited and 'tripped' by insects to bring about pollination, which does tend to mean that bees are the main pollinators, and obviously if there are few bees you could have problems. Every year it does seem that even with plenty of bees they either take a long time to find them, or have trouble figuring out how to enter the flowers (short-tongued bees can't reach the nectar and pollen so chew through the base of the flower instead, thereby ruining it.  )

If you gurgle manual pollination it can be done that way, but it's not easy and up to now not necessary here, although it can be a somewhat nervous wait as you watch all the flowers which could have turned into beans fall to the ground... 

[mumofstig]

It is so annoying when that happens!
Next year, why not try one of the new French bean/runner bean crosses.....Firestorm, Moonlight and a few others.
They do seem to set beans much more reliably and look and taste the same as Runner beans.
 
ps I do find Firestorm easier to germinate than Moonlight, though I don't know if that is just me 

[nannytroll]

Thanks for the replies. As part of my normal crop rotation, the beans are in  a partly shady plot this year, do you think full sun would be better?

[mumofstig]

Mine are always partly shaded and still crop well  (even when I grew ordinary runners)

Have you got any pots of flowers that you could move nearer the beans, to encourage the pollinators - if it's a pollination problem ?

[JayG]

The usual recommendation is full sun, but you are a little further south than anywhere in the UK, and lack of sun doesn't seem to be your main problem at the moment.

White-flowered varieties are said to set better than red ones in hot weather - that may be because they reflect the heat, stay cooler, and therefore stay on the plant longer, but it may be because they are more attractive to bees. 

Some say that misting with water helps them to set - personally I'm not at all sure about that, but it might be worth a try.....

....as well as wot Mum says! 

[chrisnchris]

I grew Firestorm last year, lack of pollination being another problem to add to my long list  this being a self pollinating variety).
It was fairly successful, we were late with planting though, some was saved seed and we had some "mutants" 

I am growing Moonlight this year (partly self pollinating)....I have noticed 3 actual beans a'growin  .......time will tell

[jaydig]

I swapped over to Moonlight a couple of years ago, and haven't had any problems with cropping whatever sort of summer we've had. I grow my flowers for cutting in a bed adjacent to the beans to try to help with encouraging pollinating insects just as an additional bit of help.  I've already picked about half a carrier full of beans, and there's lots more to come. You're right MoS, they don't germinate quite so well as others do, but I start them off in cell trays, and sow extra ones to make up for the ones that fail. I've noticed that Moonlight also freezes very well as they seem to be a bit sturdier than some of the others.

[beesrus]

I'm doing my own fertile/self-fertile field trial this year with four different runners, all due to the lack of bean setting last year.
Self-fertile Moonlight (love the name), traditional Scarlet Emperor, my own bred seeds and Enorma.
First thing, all are doing well, and all have had the same prep.
To be honest I'm surprised there doesn't, as yet, seem much to choose between the rest and Moonlight, but it's early days. The Moonlight and Enorma in particular are covered in flowers and maybe the Moonlight are just shading it so far on setting ratio. But then, insects and bees are everywhere this lovely year, so even the squash are setting handsomely and any outdoor butternut flowers I've peered into are teeming with life. It's the poor Summers I want to insure against if at all possible.

The few Moonlights I have tasted so far are very Runner like and not a bit French, so that's a good start.

[barley]

mine were full of bees today so I'm keeping my fingers crossed that finally we will get beans