My broad beans are not flowering

A planted broad beans in the beginning of September in the hopes of getting some production here in this late fall. We haven’t had any frosts yet here in GA. But these beans are showing no signs of flower production. Looking for some help to diagnose this problem.

If they are growing well it could be excess nitrogen.

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I think if you plant favas in the fall you have to overwinter and wait till the spring for flowering/production. Could be wrong with newer varieties.

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Any ideas as to why? Just length of time, or something else?

I actually planted fava beans in the summer. They didn’t take more than a month to produce flowers, but the plant was getting literally scorched. Many months later, I came across a website where I found out that fava beans are a cool-season plant.

So when I see that they’re not producing right now after about 2 months of growth, it leads me to speculate if - this may be a crazy idea - they need climbing heat in order to make them “bolt” and produce flowers and seeds.

Heat is possible, but I’d guess it’s the daylight interval. They’re probably programmed to stall/stay put when the days are getting significantly shorter.

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I wonder why there’s not much documentation on them not producing in the fall. I’m falling short on finding any info on the internet. This big ocean that is the internet. Even the university extensions. Something warning people “hey fava beans aren’t going to produce in the fall, for whatever reason that we haven’t looked into” and save people the trouble.

You might try looking in one of the many gardenweb.com (now Houzz.com) growing forums, such as Vegetable Gardening - GardenWeb. Since Houzz bought it it’s become a royal PITA to use, but there are some active vegetable growing forums where you can find more about growing Fava beans. Find a forum for your location and ask the question.

first time hear this but very interesting.
I grew fava bean before. It indeed needs low temperature weather to produce flowers and set pods. But I have never planted it in hot weather. I might try next year to see how the bean grows. What type fava bean did you planted?

My point for making that statement was to say that while they don’t like heat (i.e. summer), they still do need to get close to summer. I can’t confirm yet. I’ll grow it in the spring and keep track of when it produces.

I base my observation on:
(A) I grew them in the summer (not knowing they are a cool-weather crop) - they produced flowers fast but the plants died, because (as I now know) they are a cool-season crop
(B) But the fact that they produced flowers (in the summer heat), it might be a sign that heat is what triggers their flower production

So basically my theory is that maybe we need “bolting” to occur in the case of fava beans - i.e. “beneficial or desired bolting”, when we mostly associate bolting as a bad thing in the case of other plants.

I will have to test this theory and get back to you. The variety is unknown.

Also as @DCinFLX pointed out, it may be that the plant senses shortening daylight. Temperatures have been 60-70 daytime and 40-60 night-time. So I’ll see when they produce in the spring and if the temperatures are higher than what they are now.

I found an article that seems to answer your question. Here is what it says.

“The development of flowers and then that of seeds are key processes in the formation of yield in faba bean ( Vicia faba L.), as in other grain legumes. Winter faba bean generally has a quantitative vernalization requirement, allowing flowering to occur at a lower node than in unvernalized plants. Some germplasm is day-neutral, other germplasm is long-day with a critical daylength between 9.5 and 12 h. Progress toward flowering follows a conventional thermal-time model, with 830–1000 °C-d above 0 °C required for the onset of flowering and an optimum temperature of 22–23 °C.”

Here is the URL for the article Physiology of flowering and grain filling in faba bean - ScienceDirect

So it would appear that the vernalization requirement as well as the long-day requirement in some germplasm could be your problem.

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Woah. That’s very interesting! Awesome stuff. Thanks for digging it up.

I guess I should chill or freeze my seeds next time. I’d love to do a side by side experiment of chilled vs. non-chilled.

Additionally, I don’t think we’ll know if a variety is day neutral or not, unless we just test it for ourselves. And once we find a day neutral variety that produces in the fall, to save seeds from it.

I do have these beans planted in the sunniest spot. I know they get 8hrs, possibly more hours of direct sunlight.

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