Non setting of Greek and Nepalese giant white beans

Asked October 21, 2015, 12:30 PM EDT

I have been growing giant white beans this year with a very low yield. These plants flower copiously, form beans but they do not develop. The flowering has continued well past the season for kidney beans - mid October . What do I need to do to improve my growing regime ?
Regards Paul Pearn

Outside United States

4 Responses

I don't know where you are growing your beans, but I can give you some ideas that might explain the low yield of your bean crop. The optimum temperature for growing beans is around 18-24 C. If the temperature rose to 30C or above during the flowering stage, then it damages the flowers and you will have poor pod set. I assume that you gave your beans adequate water (400-500mm) rain or supplemental watering during the growing season. If you had a freeze during the flowering time, that could have either damaged the flowers or prevented pollinating insects such as bees from doing their part. Another consideration along those lines is whether or not chemical pesticides were used. If the pollinators were killed because of pesticide exposure, that could also lead to poor pollination and poor yeild.

This is all the general information I have--hope it helps!

Hi Alice I live in Exmouth Devon UK . The growing conditions are fine, other varieties of bean do well, so it does not seem to be an above ground problem.
I believe that the beans that I grow for drying are linked to the Northern white bean as both look identical to dry Northern beans, but much larger and were collected in Greece and Nepal . I have not grow the Northern bean so I can not compare them ( I would like to send photos but I need a standard email address as I am not up to speed with linking my photos to your site.)
Could it be that my soil is deficient in a nutrient ? Or the lack of the correct nitrogen fixing agent ?
Regards Paul

It could be that the beans won't grow well in your may be that they were well-suited to their countries of origin, but not where you live. I think the fact that they are continuing to flower later in the year supports that. Perhaps the place you got them had a much longer growing season. Your nights must be getting cooler now that it's toward the end of October, and the flowers aren't happy below 13C. If your other bean plants are doing well, I don't believe it's a below-the-ground problem. I believe it's environmental.

Here's some information about the problems encountered when growing beans. Hopefully you'll find more information there. Excerpt from the article below:

Plants flower, but blossoms drop. There are several possible reasons: (1) Night temperatures are too low, less than 55°F (13°C): use a hormone spray to improve fruit set during low temperatures and keep soil evenly moist. (2) Day temperatures are too high, greater than 90°F (32°C): there is no solution, temperatures must drop. Also weather may be windy. (3) Smog during blossoming period: tap on blossoms 3 times a week when flowers are open to assist pollination. (4) Too much nitrogen in the soil: feed plants properly; (5) too much shade: plant beans in full sun. (6) Early blossoming, then drop: don’t plant too early, early blossoms will not set fruit. (7) Variety planted is not adapted to your region: get regional suggestions from a garden center or the cooperative extension. Avoid planting Blue Lake, Kentucky Wonder and pole lima beans which are especially susceptible to blossom pod drop. Plant quick-maturing varieties

Thanks Alice
Regards Paul