Last time I showed my trellis someone wanted to know how I built it. So here here are the instructions. My beds are 4' wide and 8' long. In the past I've put one trellis along the northwest side of the bed and I've grown something shorter along the southeast side of the bed (the sunnier side). This year I'm putting in a trellis on both sides and will see if both sides will grow well or not.
I build this out of poles that are 8' long and 1" in diameter. I take three sets of two poles. Two sets will be put at opposite ends of the beds and one in the middle. One pole in each pair is placed along the edge of the bed and the other is placed 18" in front of it. I push them as far into the ground as I can. It is OK to have one pole stick up longer than the other.
I suppose I should talk a little about string. I use jute. This trellis takes a lot of it. I find it much cheaper to buy my string in a huge roll that lasts for years. I like using string because at the end of the season I can just cut the whole thing down and compost it. When I do my tying I use about a yard at each joint for joints with just two poles. I use 50% more if there are more poles at the joints. I loop the string around multiple times and really pull tight.
After I have my top cross bar up, I put up two cross bars about a foot from the ground. One on one side of the trellis, and one on the other. As you can see I do one end first. Then I do the other end, then the middle. You may ask why I put them a foot above the ground and not closer to the ground. I find it easier to weed the bed if I don't have to go through a trellis. Also the beans can find their way up with no trouble at that height and it uses less string.
The other end of these diagonals rest on the bottom bar and are tied to the bars at the ends. I only put diagonal bars on the side of the trellis that faces outside. If you feel your trellis at this point it is pretty stable.
My site however is very windy. Over time the trellis rocks back and forth. The beans growing up are like a sail. First one side gets buffeted and then the other. Over time the trellis will lean into the bed. This is because my pathways have very solid soil from walking on it all the time and my bed has very loose soil. So the poles on the outside near the paths can't dig themselves farther in. While the poles on the inside of the bed get pushed farther and farther down. I fix this by adding a side brace. I can't show you as the one I built had two trellises on each side of the bed. But I put in one more supporting bar that is tied to the trellis at the two corners of the bed and is pushed against the wood of my raised beds at the other. I do it diagonally from the trellis side down to the edge of the bed.
But this time I made two trellises and connected them with a cross bar at the sides that just connects to each trellis. I'm hoping that is good enough. I get some pretty strong winds here. I've been here three years and have seen two wet microbursts so far. I don't know what wind speeds we had as my weather station has a broken wind meter but they can generate speeds over 140mph (we didn't see even close to that speed I'm pretty sure though it was destructive and brought down more trees in our town than Sandy took out and the microburst covered less than a square mile and only lasted about five minutes). They arrive very suddenly and don't last long and effect a very small area. I saw my bean trellises bending to about a 45 degree angle during one but it stayed up. The bamboo didn't break (go bamboo) and the beans survived. The rest of my plants were flattened except interestingly enough some corn that was planted between two of my bean trellises.
Now on to the strings. Because of my winds I've found that I need to keep the strings from moving sideways along the pole. I made a string with loops in it every 6". The string has a foot on either end without loops to tie it down to the top cross bar.
To put up the bean strings I take an end and put it through one of those loops and then over the bar. I tie one end to one bottom bar and the other end to the other. I will plant two bean seeds under each end of the string. So the beans are actually growing up both sides of the trellis.
Sadly some of them have been laced. This one will survive. But others have been totally eaten. I'll have to seed some more today to replace them. I think the rolypolys have been at them. It might be slugs, but with the dry weather we had for most of the spring it is more likely not.