[diarmuid]

I've grown Scarlets and Painted Ladies together this year and have harvested beans for planting next year. They will have cross-pollinated, no doubt.

Put "runner beans cross pollination" into Google and every site will tell you to:
- " only grow one type of runner bean"
- " Varieties must be separated by at least ½ mile to ensure pure seed" - that's a challenge in my garden

Other than the excitement of waiting to find out what my crossed variety will look and taste like, what else can I expect and why is the consensus not to cross? Is it immoral? Is "Bean Purity" so important?

Educated opinions or rants, please.

Thanks

[tagwex]

That would be a challenge in most peoples gardens unless one is a TD or MEP! Cannot wait to hear the answers to this one. I had two types of beans this year so according to your findings I could well have a mongrel variety next year. I have to wonder how allotment owners and people in rows of houses manage to keep their seed pure.

[Dr. Sunny Thomson]

[Greengage]

This is an excellent question, If you look up Scarlet runner beans it says the are self pollinating but this is not possible as they need insects to trip them i.e open the flower to allow insects deposit pollen to them, Im not sure but it may happen that they cannot cross, I also googled it and came up with this info from an American site,

The runner beans (P. coccineus) will cross with each other but not limas or common beans. (snip)

It is rare, but runnerbeans and common beans can and do cross. I had a cross several years ago, and it has been fascinating. At first I did not recognise what was happening - a common bean with red and pink flowers? But the flowers looked different from runner bean flowers. The pods were short, rough skinned, sparse, late maturing and the few black seeds they contained were of irregular size and distorted shape.

The following generation I had some cotyledons in the ground and some above. And the most exquisite flower colours imaginable. Peach, pink, purple, pale blue, apricot. The resulting beans were smooth podded and quite variable in type and yield, including just a single yellow pod on one of the plants containing two tiny seeds. One germinated and I got a very strong growing tall plant with large yellow pods and large brown seeds. Another of these second generation hybrids produced small seeds but with the same markings as the runnerbean that I suspect to have provided the original pollen.

All of the offspring of the cross have become much heavier bearing than the original cross. They still have remarkable flower trusses, but the colours are more muted now. They grow strongly and produce very well, especially later in autumn, when the ordinary beans and the runner beans have stopped. So far the hybrids haven't really stabilised much. I most often get black seeds now, but some are white or other colours.

It is rare, but if you get a chance cross, it is fun following it up, even though the first filial generation isn't very promising.

http://forums.gardenweb.com/forums/load/legumes/msg0208425612012.html?9
It will be interesting to see what others have to say.

[Blowin]

I contributed to an earlier thread on runner beans and reported on the poor performance of my Cobra seed but, to give them a chance to redeem themselves, I planted the few I had left with a separate wigwam and grew them on, purely for 2015 seed.

To me, the standard seed is a mauve colour with black speckles but some of the more exotic varieties are white, black etc. The Cobra were pure black and about half the size of normal seed. To my surprise, when I stripped the wigwam and extracted the seed, they were all mauve/black, i.e. normal colour.

My interest is solely in producing food and my seed, whether bought or saved, have always been a mixture. Crops have been good throughout so, unless an individual has a particular reason for one variety, I'd say there's no cause to worry what's crossing with what?