A-frame trellises... that is a good use of home-grown poles. A well-supported system, especially when braced on the ends as in the top photo. Little digging or pounding involved, but a lot of tying.
No idea. Just an example I pulled off the internet. My garden is not that pretty looking. This is my first year putting poll beans in the big garden so it’s the first year trying the A-frame trellis. I had forgotten what it was called so thank you! That would be an insane amount of chive though!
I like the single poles as it seems faster and easy. I think of it as very efficient. I do have to do the prep of cutting points on them, long taper makes them easier to drive into the ground I think. In the autumn I store them away in my garage and they are ready for the next year. I've grown pole beans like this since 1975. I can put garden fabric between the rows easy too. To me it all seems nice and straight, square, neat and quick. In my 2019 pole bean garden I put up 126 poles this way in about 4 hours. I planted 504 seeds around all those poles and was done about 7 pm. I started about 10 in the morning. I enjoy looking at all types of suport structures that people come up with, but still seems like more work than I want to do.
In loamy soil, maybe. The problem is the wind, how windy is your part of Ontario? I've seen your trimmed cedar photo, how long are they? By the time you set them down deep enough to be stable they may not be that high off of the ground. To me the height isn't the big issue, it's just getting the bean pods off the ground so they don't rot or sprout because they are touching the ground.
T-Posts can get expensive. They come in different lengths too. If you are going to do that just use taller T-Posts. Forget the saplings. Or get shorter T-Posts and do as you said to get then higher. Something just goes against the grain in cutting T-Posts. It just doesn't sound right.
I'd think the tripod is probably the simplest. The problem with the tripod is the skinnier it is the more unstable in a high wind but the flatter you build it to keep it stable the more room it takes up.
If you go with the tripod just plant one variety on a tripod. When I plant network beans I try to keep each variety by itself but I also look at the bean itself so I plant totally different looking beans close to each other. Once you get out there and actually do it you'll probably find it isn't that big of a problem. It's the thinking about it that gets you. But you need some separation between varieties but since the beans look so different there will be no mix-ups when you hull them. If you get a segregation you'll want to be able to identify which bean it came from but that should be easy.
i picked out Huey, Purple Dove and Top Notch for starters, we'll see how those do for them.
How many years of use can you get out of a pole @Bluejay77? Is it difficult to get them out at seasons end? A 1X2X8 here is about 2.50, which is not bad if I can get a couple years out of them. I've used some of these before to stake tomatoes, but they often broke at their joint when I tried to pry them out.
