I'm growing http://www.mr-fothergills.co.uk/catalogue/product/bean-broad-karmazyn/12572/
and they're in flower, ;D
Is it too early?
Could frost kill the flowers?
The other odd thing is my plants are only about 12'' where as on the MrFothergil's site it says they should be double that, will they keep going or is that the max height?
(http://www.allotments4all.co.uk/smf/gallery/10575_23_04_10_11_54_00.jpg)
Mine are the same. I sowed mine in the autumn and they have survived the harsh winter OK but are definitely on the small size. They are growing at quite a pace though so they may yet catch up with themselves. As for frost ....don't know the answer to that one. I think they'll be fine. I have given mine some chicken pellets and a good water.