Growing Two Varieties of Runner Beans-How to Keep Pure?

[blackox]

So I have two different types of runner beans that I want to plant next year, Sunset runners and some runner Canellinis. My question is how can I save the seed from these two varieties without having them cross? Is there an easier way than bagging the flowers that would give me a larger quantity of seed?

[trixtrax]

Give them as much space as possible for two reasons this includes adding into the element physical barriers like forests between plots. The outcrossing rate is high comparatively high to Phaseolus vulgaris. Around here a lot of bumblebees seem be interested in the flowers.

[12540dumont]

I plant my beans in rows and separate them by forests of corn. So that the bees have to go up and over the corn to get to the next type of bean. I also surround runners with phaseolus vulgaris, because these two can't cross. You can also surround them with limas. HOWEVER, on my farm, the lunatus does not bloom at the same time as the coccineus.

My runners bloom from early spring right through to fall. Even with these precautions, I have seen some crossing. You will know if you get colored beans in your canellinis or white beans in your Sunset that you surely have a cross.

Crossed do not always turn up in the seed coats the first year. So, keep an eye on them.

[robertb]

Judging by my experience on the allotments, a hedge or equivalent is a pretty effective barrier to pollinating insects. Other possibilities are hand pollination combined with isolation with netting or similar, and growing them alternate years.

[hortusbrambonii]

Maybe there is another way?

If your season is long enough you could try for some kind of time segregation. Let the first blooming variety flower until it has a lot of young pods, and if the the other one starts blooming cut them off while still unopened. Then when the first variety has enough pods make sure it won't bloom any more by removing the flowers on that one now, and let the second one make flowers and pods...

(Flowers of Phaseolus coccineus, even unopened, are edible btw)

[blackox]

Thanks for the replies everybody! Luckily I have a lot of seed of each variety and plenty of time, so I can try both ways or maybe a combo. Maybe use the barn as a barrier and make sure that they have different flowering times, and mark the pods to be saved for planting with tape? hortusbrambonii, I heard that runner flowers were edible but have never tried them before, I will when I plant them though.

[paquebot]

It's not an issue. Cannellini is Phaseouls vulgaris. Sunset Runners are Phaseolus coccineus. All P. coccineus will cross with one another but not with any other Phaseolus species.

Martin

[raymondo]

Isn't there a P. coccineus cultivar with white seeds used as a large Cannellini and often referred to by that name? Can't confirm this but I remember something like this. Either way, you'll know whether your Cannellini is P. coccineus when it emerges from the soil. If it leaves its cotyledons underground, it's P. coccineus.

[paquebot]

Any large white bean may be called Cannellini in the culinary trade and a number of P. vulgaris are called runners but the Cannellini sold in the seed trade is a kidney bean, not P. coccineus.

I'll add that there is a large white bean available as seed, Aztec Half Runner. It is also sometimes called a potato bean. Although called a half-runner, it is P. coccineus and will naturally cross with Scarlet Runner. By its shape, it should not be easily confused with a kidney-type bean.

Martin

[raymondo]

Thanks Martin. I bought a white seeded runner to try this season called White Dutch. I'm hoping it will make a good baked bean.

[paquebot]

I've never had enough runner beans to bake but used the Aztec ones in my bean soup mixes. Their cooked texture is indeed similar to a potato. Of course, they are quite large then as they expand to more than twice their dry size.

Martin

[zeedman]

The best suggestion I could make for saving seed from two runner beans would be alternate-day caging. Cover one row with a light floating row cover just before full darkness (when bees are not active), leave it on the following day, then go out that evening & move the cover over the other row. Make sure no bees are on the cover when it is moved... I've found bumblebees sleeping on my plants, and they are the main pollinators for runner beans. Repeat the covering process, alternating between the two varieties until enough pods have set for seed. Tie strings around the stem of those pods to identify them... then unless you want to keep flipping the cover all summer, just let the bees do their thing for the rest of the year. If you cover the trellises with hoops to support the row cover, it could be moved & secured in place fairly easily, and lessen the chances of tearing the cover. The hoops should be made of smooth, non-abrasive material to avoid tears. PVC conduit is one of the best materials; it bends easily & can be placed over rebar stakes driven deeply into the ground.

If you plant one variety several weeks before the other, you might get some pure seed through time isolation. Don't know your climate, Blackox, but if your summers heat up quickly, you might want to try that first variety as transplants. Runner beans flower very quickly, I've had some begin blooming in as little as 30 days. If you can get them to bloom before the heat sets in, you might get an early pod set before the other variety begins blooming. You would still need to use caging or hand pollination & blossom bagging for the other variety.

Oh, and as Paquebot stated above, the true Cannellini is P. vulgaris - and a bush bean. The beans sold as "pole Cannellini" are generally white-flowered / white-seeded runner beans... sometimes identified as such (as is the case with the one offered by Seed Savers Exchange) but more often either misidentified as P. vulgaris, or with the species left unstated. If we knew the source of the seeds, it might be possible to make a better determination as to their identity.

[blackox]

Hi, everybody! Sorry it took so long to reply, I've been helping a local farmer take his crops in from the field.

I am pretty sure that this is the P. coccineus cultivar, as raymondo mentioned, but will poke a seed into the ground real quick to see if it is P. coccineus or not. The seeds are actually pretty large and plump when dry. My mom originally ordered these from a website to use in the kitchen. I'll have to ask her what website she ordered them from. At first I was less enthusiastic about saving the Cannellinis because they seemed dull compared to Sunset runners. But they seem to be harder to find in the U.S. I've only found two, maybe three, websites that offer them.

Zeedman, thanks for the description of the caging process. I have some tomato hoops out back that can be covered with row cover for this. I'm typing this in Central Ohio. We've had some odd weather lately. The winter of 2011 was nearly nonexistent. And this summer we have had four 104 degree days in a row. So it is hard to tell what this next summer is going to be like. We have bumblebees all over the place so now that I think about it, barriers by themselves may not work out that well. Will caging work on other open flowering legumes such as limas or cowpeas?

[zeedman]

Will caging work on other open flowering legumes such as limas or cowpeas?

I don't generally cage either bean, but know a grower in the Carolinas who sometimes cages his beans, including limas. The caging was necessary because he was saving seed from multiple heirlooms, and it needed to be pure seed. He used mosquito netting for caging material - permanently attached to hoops - and got a pretty decent yield.

One year I tried caging common beans with floating row cover, and didn't like the results. When left on long term, the spun polyester caused disease issues, probably due to the extra humidity trapped inside; peppers like that humidity, but beans don't. When I removed the covers, the new foliage on the beans came out healthy, and the plants eventually made a full recovery. The grower mentioned above used mosquito netting because it had better air circulation than spun polyester. Tulle fabric works too for the same reason, and while it is not UV resistant like the mosquito netting, it is far cheaper & easier to find.

Chances are that I will be caging some limas next year, because I am behind in my grow outs, and have several varieties that are old & need to be grown out for fresh seed. Provided that my plans don't end up scuttled due to work or bad weather (as they did this year) I'll report on the results.

Cowpeas, in my experience, don't cross as easily as runner beans or limas. In my rural plot, I generally grow 5 cowpeas and/or yardlong beans per year, spaced 50-60 feet apart. There are trellises of pole beans between them, including limas & runner beans. While I only grow one lima & one runner bean in that plot, I will use multiple rows at several locations, to act as isolation barriers. There will also be a squash or cucumber between varieties, and patches of free-blooming annual flowers. Whatever barrier crop is used between varieties, it should be blooming at the same time as the plants being isolated (in this case, cowpeas). Using this method, I have yet to see a cross in my cowpeas. It may be that different cowpeas could be grown even more closely without crossing... but due to their large conspicuous flowers, I prefer to be cautious.

If anyone has used floating row cover on cowpeas, I would be very interested in hearing the results. My suspicion is that they would handle the extra humidity better than beans, and set pods well without pollination. I hope to put that theory to the test next year.

[paquebot]

There's definitely more confusion with this one. Cannellini is a bush bean, P. vulgaris, without question. White Runner Cannellini/Runner Cannellini/Pole Cannellini is P. coccineus. If purchased for eating, they may not even be Cannellini but a similar white bean. Cannellini looks very much like it would be a kidney bean if it were red. White Runner Cannellini seed would look like a Sunset Runner if it were purple. Compare them and see how close they are for shape. I've grown them both but can't locate my reserve Sunset Runners.

Martin