Is it too late to post a few photos?....are they dead and gone? If some are still eeking along and you don't mind carefully pulling a few up, it would be interesting to see the roots. Also see http://aggie-horticulture.tamu.edu/archives/parsons/vegetables/bean.html in case something pops up in the list. Don't worry if it recommends using a fungicide.....there is usually an organic work-around to at least try.
“The most important decision we make is whether we believe we live in a friendly or hostile universe.”― Albert Einstein
I also struggle with phaseolus beans, as their performance has been inconsistent from year to year. My last few years went like this,
2014. The best year I've ever had. Healthy plants shot up at great speed to eight feet, with only some minor leaf rust issues. Tremendous yields of pods over a long period, followed by a huge crop of dry beans.
2015. The worst year I've ever had. Same variety, seeded in the same month, applied the same light compost dusting, etc. Plant's struggled for months to reach a measly three feet. Produced only a small handful of pods, but failed to mature beans. A complete loss from all plants.
2016. Same variety and culture as 2014 & 2015. It's shaping up to be an average year, plants are healthy, and growing at a moderate pace. I'm hoping for at least something this year to replace my old seedstock.
I think that beans may be sensitive to changes in weather, but I'm not really seeing a pattern as to what weather does what. Supposedly, beans will fail to flower and set pods at very high temperatures. However, in 2014 I also saw huge yields from okra - a plant that really thrives on heat. Likewise, I had terrible okra performance in 2015. Both years were hot, with similar below average rainfall.
I've never had a good bean crop in this garden. In my old garden a few yards away, I had one good bean year. Beans just don't like it here, I guess. Soil is clay, still rather heavy after a few years of mulching.
Oh wow, I just realised the beans I'm currently trying to grow aren't even Phaseolus, they are Vigna (Yard Long Bean). Oh well, both kinds of beans have done poorly, but I've been able to grow cowpeas and teparies in the past in my old garden a few yards away.
Did you add any bacterial innoculant to the soil to support the beans? Mixing a little soil from the successful plot could introduce these, if that's what is missing. I hear light green leaves and think nitrogen deficiency. If it where me, I'd try to introduce the appropriate micrology and give supplemental nitrogen while that got established (this is a good opportunity for diluted urine or careful chicken manure application)
Yard long beans are one of those true hot season crops. In my garden my runner beans are producing right now, the Kentucky Wonder have just started (traditional green beans) and the yard longs are still very short.
If you are having trouble growing beans it might be a nutrient defect that is the problem.
Beans are usually thought of as "easy to grow" but they do have some requirements to thrive and they are fairly heavy feeders so they might grow really well in your spot for one or two years then fall off in growth and or production.
The main requirements for good bean crops are;
friable soil that drains well
equal density of Nitrogen, Phosphorus, Potassium
adequate zinc, calcium, molybdenum, manganese, iron and other micronutrients.
With out these beans can be stunted in growth and they won't be prolific in production.
Leaves can give you good clues as to what is missing in your bean patch, for example:
Yellow top leaves along with brown bottom leaves and stunted growth means you are missing enough zinc and iron.
An inexpensive soil test kit is a very worth while expenditure, they can be found for under thirty dollars for a 20 test kit.
If you have a worm bin you can add castings from worms fed a variety of vegetable matter
If you take multi vitamins yourself, dissolving 4 tabs in 1 gallon of water will give you a solution you can dilute 4:1 and water the plants.
That will give you all the main micro nutrients the beans need to thrive.
IF you also inoculate the bed with mycorrhizae, the hyphae will attach to the bean roots and help with mineral up take.
William Bronson wrote: This is gonna sound dumb, but, I thought beans and peas fixed their own Nitrogen from the air? I must be way off.
It's actually this interesting process where the legume roots have a symbiotic kind of relationship with a certain bacteria, and the bacteria is what makes the nitrogen that the legumes use. This is just a quickie paper I skimmed to check out, but it has some good basic information on it (I only know it because I was having struggling beans too last year and thought the legumes made their own nitrogen too, and someone pointed me in the right direction. ^_^ )
Yeah, that! So, no good bugs, no nitrogen fixing. I guess I thought bean seeds were pre-treated, or if saved from last years crop, naturally inoculated.
Guess not always.
I got a crapload of naturally occurring Mimosa, would the soil from their roots count as an inoculate?
Depends on whether they are evolved to work with the same kind of bacteria. That's why I was recommending Tyler add some soil from where she did have success with her beans. Burpee seed company has started to sale a multi species bean innoculant alongside their bean seeds. I saw it for the first time a couple of years ago. Once you've got your soil innoculated it shouldn't require additional doses unless you go several years without growing any beans there. I don't know how many, but unless your beans show signs of suffering I'd assume you've got enough.
Nitrogen fixers are really misunderstood by most, because of the way they are usually represented to gardeners by both "scientist" and Nurserymen.
What they do is attract Rhizobia bacteria that form in nodules on the roots, these bacteria change the free N2 into usable forms of nitrogen.
With out the Rhizobia bacteria, even animals can die from lack of Nitrogen.
The guys we want in our gardens are Rhizobiaceae and α-Proteobacteria these are the two species that do the nitrogen conversion for us and our plants/ animals.
When we grow known nitrogen fixers what we are really doing is growing plants that gather up usable nitrogen, the soil improvement only comes after these plants die.
1/2 of the process is the release of the gathered nitrogen when the plants decay.
The other 1/2 of the process is the bacteria living in the soil, they continue to convert N2 even after the plant above ground dies back.
I've been throwing peas in with my potted corn, thinking that they would enrich the soil as each grew.
Perhaps they will at least not compete for nitrogen, and as I have discovered a fondness for the pea greens, maybe I can promote some die back in the roots by harvesting them for stir fry.