A shoutout to bush and pole bean mavens

Hi folks!  I'm observing something a I think is  a bit unusual, but I can't come up with an explanation for what I am seeing.
My Zone is 8b, east of Seattle, with about 2 to 3x the number of sunny days as Seattle proper.  I am growing in raised beds constructed with Hugelkultur technique, with my soil layer consisting of a modified Mel's mix made with coir, pumice/perlite, 2-3 types of commercial organic compost as well as worm castings and a bit of topsoil.  I generally have reasonable success with most things I plant, barring insects or boneheaded mistakes of my own.
Here's what I'm seeing now for the 3rd year in a row :
1.  For both bush and pole varieties, every year the purple variants come out of the gate like gangbusters and are pretty prolific.  Everything is direct sown.
2.  I am seeing comparatively very late germination of my green types - both Blue Lake and Provider and the same for my yellow wax beans.
3.  The greens and yellows also germinate quite poorly - sometimes as little as 20%, while I consistently see 90-100% germination of my purple variants.  All of my beans are of similar vintage, being 1-4 years old.
I am wracking my brains trying to understand why these beans are so late to germinate and have such a bad percentage compared to all of my purple variants - of which I have 4 or 5.
I'm at the point where I feel it's not even worth the effort to plant the green and yellow varieties.  
My past experience has been that when I have poor results, it almost invariably is because I did something dumb.  But c'mon guys, these are BEANS - and some of them do just fine.  
Your perspectives and experiences would be very helpful - so thanks in advance!

We find that different bean types have different seasonal rhythms. So I'm not sure this is unusual. We plant bush beans, scarlet runner beans, and blue lake pole beans at roughly the same time in late spring -- and they "peak produce" roughly in succession through the season. This is actually a good arrangement for us; if they all came at once we could not possibly handle them all.

BTW, what are the purple pole beans you plant that are early producers?

Hi Russell,
It sounds like you have been using the same seeds each year? I wonder if you got a bad batch. I would try a germination test.

The paper towel method is probably easiest. You can look up specifics online, but generally you get a papertowel damp, put some seeds in it, put it in a plastic bag, and put it in a warm place for a few days. If the problem is with your soil, then they should germinate well. If the problem is with the seeds, then you should see the same 20% germination rate as in the soil.

Let us know how it goes.

Although not ALWAYS accurate, I use the float test on any bean seeds that are more than 2 years old. Drop the beans in a cup of water. If they float, they probably will not germinate. I plant any that sink.

Joshua States wrote:Although not ALWAYS accurate, I use the float test on any bean seeds that are more than 2 years old. Drop the beans in a cup of water. If they float, they probably will not germinate. I plant any that sink.

Hm! That's new to me. Interesting!

I would question the age of the seed, followed by where you acquired it.  If the seed is older, where was it stored?  I seldom have germination issues with beans and am finding that my saved seed often germinates at 100%.  

I constantly had issues with bush Lima beans germinating poorly and blamed it on grower error.  Bought a second package of seeds from a different supplier and had excellent germination.  

I regularly grow one variety of purple pole beans and find them incredibly prolific but some of the green varieties produce equally well.  As for bush beans, Provider has produced well for me a long with Cherokee Yellow Wax.  One thing I often do with new varieties that I have limited seed of is to let the seed soak in warm water for a few hours before planting.  I've only had one variety to germinate poorly after soaking and I believe they soaked a bit too long as direct-seeding the same variety without soaking was successful.  I'm not suggesting soaking several pounds of seed, but maybe give a handful a try to see if it makes a difference.

I don't know, but I also don't feel the need to figure this kind of thing out. I just save the seeds that do well and over time and my grex of beans bends toward something that does well in my garden.

I'm having the same issue with scarlet runners, which I have planted at least 3 times this fall and not one has come up (where I live they're a winter thing). In fact this thread is a good reminder to get soaking, I'm going to try sprouting them in a paper towel.
It's disappointing considering beans are probably the easiest thing I grow, and kids do it in nursery school. I was thinking some of these seeds I have are quite old, and maybe were damaged by weevils.... then just now (edited) I went to get the beans to sprout and realized that they're all gone. I planted an entire new pack from Baker Creek that I bought last August, which were kept in the fridge the entire time.

Russell,

I am in a similar growing zone. We have had very dry conditions until this week when we have had many many inches of rain in a matter of 48 hours. My Blue Lake beans I have planted thrice. They finally took, but at two months old and with irrigation, are barely eight inches high. I have seeds from a friend and they are also going very slow. The Blauhilde (purple) are the only ones actually growing with a bit of fervor, however only two plants germinated. In short, I am having almost the same exact experience and I'm flummoxed. I was really counting on these beans for fresh eating and pickling!

@tereza when you eventually manage to get your scarlet runners to grow, leave the plants in the ground, they are perennials and will come back again.

This is cool! We do this with our dry beans before soaking (in anticipation of cooking), never thought to do it before planting. Thanks!

Joshua States wrote:Although not ALWAYS accurate, I use the float test on any bean seeds that are more than 2 years old. Drop the beans in a cup of water. If they float, they probably will not germinate. I plant any that sink.

Megan Palmer wrote:@tereza when you eventually manage to get your scarlet runners to grow, leave the plants in the ground, they are perennials and will come back again.

I wish that were true here. I go to great lengths to harvest seed. I wonder, at what stage could I harvest the roots and bring them into my cold room to jumpstart next year's production? This would be huge.

Douglas Alpenstock wrote:
I wish that were true here. I go to great lengths to harvest seed. I wonder, at what stage could I harvest the roots and bring them into my cold room to jumpstart next year's production? This would be huge.

Douglas, our winters are much milder than yours so we leave them in ground, I have never lifted them. Perhaps you could try leave some plants in ground and protect with a heavy mulch and removable cold frame?

I would guess that if you wait until the leaves have all started to die back in autumn that would be a good time to lift them.

Please do let us know whether either or both methods work for you.

Megan Palmer wrote:

Douglas Alpenstock wrote:
I wish that were true here. I go to great lengths to harvest seed. I wonder, at what stage could I harvest the roots and bring them into my cold room to jumpstart next year's production? This would be huge.

Douglas, our winters are much milder than yours so we leave them in ground, I have never lifted them. Perhaps you could try leave some plants in ground and protect with a heavy mulch and removable cold frame?

I would guess that if you wait until the leaves have all started to die back in autumn that would be a good time to lift them.

Please do let us know whether either or both methods work for you.

It may be possible to lift them and store in the cold room -- a worthy experiment.

Our climate reaches temperatures of -40C. The ground is frozen solid to a depth of 6'/2m or more. Scarlet runner beans will not survive without extraordinary measures.

Megan Palmer wrote:@tereza when you eventually manage to get your scarlet runners to grow, leave the plants in the ground, they are perennials and will come back again.

I've tried this here in the UK with no success. Once I tried heavy mulch in situ - no joy, they seemed to rot in the soil. A second time I lifted them once they had died back and stored them in the cold and dry, wrapped in newspaper. No joy there either.

I'm sticking with seeds until someone comes up with a hardy variety selected for overwintering potential.

Wow! Thanks everybody for your prolific replies!  Lots of helpful info here!
Here's what I've been planting:  
Among the pole beans the winners are Baker Creek Blauhilde, Purple Podded Pole and to a lesser extent, Monte Gusto Yellow Pole beans (from a different source)
These seeds are all 4 to 5 years old and consistently germinate at 90%+.
The poorest pole performer is my Botanical Interests Blue Lakes - 20 to 30% germination at only 1 year old for the packet.
On the bush side, I'm having success with Royal Burgundy, with very anemic germination from my Gold Rush and (so far) no germination with my Providers.  These seeds are all 1 year old.  The Providers and Gold Rush all pass the "float test."
Right now I'm going to try some paper towel germination of a batch of Providers and see if that yields any useful info.

We have given up trying to pre-soak bean seeds. It works for squash and such, but beans rot more often than not. So we just plunk them in warm moist soil.

Well, about 7 days ago, I took a batch of my Provider bush beans and soaked them for 24 hours, followed by an attempt a germination using the wet paper towel method.  It's so far taken a full week to get 10% germination, which is pretty disheartening.  I'm going to continue for another week, but it looks like I'm running a race with the beans rotting at this point.  The preliminary indicators are certainly pointing in the direction of bad seeds, though.