Non-productive beans

Asked August 18, 2020, 10:12 PM EDT

For two years, I planted dragon-tongue beans. The plants were healthy, but they never blossomed and no beans were produced. After last year, I planted the beans in a different bed. Also, the seeds came from two different sources, the last being Johnny’s Seeds. My soil was tested three years ago and is fine. Additionally, last year’s bed successfully grew tomato and pepper plants, photo also enclosed. In advance, thank you.

Anne Arundel County Maryland

3 Responses

Hi- we don't know when you planted the seed but this cultivar should reach 24-30 in. in height. These plants appear to be much shorter. We can see evidence of Mexican bean beetle feeding and possibly potato leafhoppers (small insect that flies up when disturbed) and spider mites (examine leaf undersides with a hand lens for signs of mites).
See more information on these pests:
https://extension.umd.edu/hgic/topics/vegetable-problems

However, these pest issues do not appear to be severe and would not prevent plants from growing and flowering as long as they received adequate water and nutrients. The light green leaf color suggests that nutrients (especialliy nitrogen) may be in short supply. The yellowing and decline of older leaves is natural for annual plants but is accelerated by environmental stressors.

The other major issue this summer was 25+ days of 90+ degree day temps in July and warmer than normal night temps. This effectively shut down flowering and podding in many cases, especially where bean plants were in "hot spots" such as near brick walls, full-sun Southern exposure, etc.

It's possible that your plants could start to flower and pod after a light fertilizer application. If they don't respond by flowering you should probably pull out and compost this crop.
Jon


Jon,
Thank you for your helpful response.

I fertilized the bean plants once with Espoma garden-tone. I don’t have my garden journal in front of me, but the plants were planted long enough ago to have had born fruit.
Given the sickly look, I pulled them out today and noticed a few plants with flowers. It must be a delay, given the extreme temperatures in all of July.
I was stunned to see what appears to be evidence of root knot nematode on the roots. (See photo)
Again, thank you so much for your very helpful assistance.
Best,
Elle

Hi- that does appear to be RKN- thickened roots and swellings- and would explain the stunting. Nodules that encase Rhizobia spp. bacteria are roundish, easy to rub off the root, and pink inside.

Please read more about managing RKN in the garden:
https://extension.umd.edu/hgic/topics/root-knot-nematodes-vegetables
Jon