Beans - cross fertilisation

[frankerooney]

A bit early to be thinking about climbing beans, I know , but I would like to be sure I'm going to be planting them out in the right place. I'm planning to grow runner, borlotti and French beans and I'd like to put them side by side along a fence. I'd like to save beans from each variety for next year. But did I read somewhere that they're likely to cross-fertilise?

Can any of you lovely people help with this?

[Eyren]

Runner beans definitely cross-fertilize between varieties, but I'm not so sure about French ones (borlotti are "French" beans too - they all come from the Americas, but they came to England via France, hence our name for them). Runners and French beans don't cross AFAIK, as they are different species.

[frankerooney]

OK, thank you Eyren .

[Flummery]

It's possible - but not all that likely - to get a cross with 2 lots of french beans close together. It's never happened to me and I sometimes grow 2 types either side of an A frame. However, one of the dwarf french beans I got from the Heritage Seed Library threw up a climber - red pod, black seeds. This must have been a cross. I'm growing those on as an experiment this year!

I would think you'll be fine if you grow the runners in between the two french types. However, if anyone within a mile (yes, really!) is growing a runner you could still get cross breeding. I still think you will get something interesting and edible. I wouldn't worry.

[frankerooney]

That's great, Flummery - very helpful, thank you.

[Eyren]

Good to know that about the Frenchies, Flummery - I thought they didn't interbreed, but didn't want to say so just in case. I shall be growing various climbing French beans, but would rather they didn't cross as I want to save the seed...

I'm also going to be growing Desiree and Red Knight runners together this year. I chose them just because they are both stringless and I thought the red and white combo would be pretty - but I read here on the Vine that they cross easily to produce black beans

[Two_Sheds]

Every year I grow about 20 different kinds of French beans, next to each other. Never had a "cross" yet.

[Alison]

As I understand it, runners are the sl*ts of the bean world but Frenchies prefer to keep it to themselves!

[Protea]

From the veggie breeder (well sort of)....its incredibly difficult to cross a runner with a frenchie...although we have now managed it!

So to answer your questions - they'll be fine - grow them all together

runners will cross pollinate amongst themselves.

[King Carrot]

one bit of useful info I remember concerning growing and saving French bean seed is not growing the same or similar coloured beans of different varieties beside each other so you know which is which for sure, and if you keep alot of seed, label each type as one type of French bean with black seed looks remarkably like all the other types of french beans with black seeds

[GardeningMike]

I think everything has been said...
Under normal outdoor conditions, runner beans will cross-pollinate (thanks to bees) so if you grow two varieties next to each other the progeny will likely be a mix of the two 'parents', segregating their characters most clearly in the second generation that you raise from this cross. French beans self-pollinate (without need for insect pollinators) but stray pollen via bees cannot be ruled out completely and cross-pollination might occur ocassionally. French and Runner beans are not incompatible when it comes to cross-pollination but again this is likely to occur less commonly. In their native wild habitat in the Andes, the dwarf beans are found at the warmer lower altitudes, and the runners found in cooler parts higher up, with hybrid runner/dwarfs in between.