Use cable (clothes line) for the horizontal lines.
Use cotton cord for the vertical lines.
When the bean vines are starting to run, wrap the cord around the vine loosely & retie the cord.
Do this as the bean grows.

When I first began growing pole beans, I used pretty much the same setup: horizontal strings top & bottom between poles, with vertical strings running between them above each plant. I experienced two different problems:
(1) During heavy winds, the vertical strings would slide on the top string & get pushed to one side. This would damage some of the vines.
(2) When heavily laden, the vines would weigh down the top string, which would pull the poles toward each other & cause sagging of the top string.

Both problems can be overcome by using a rigid crossbar as the top piece, in place of the string. Rebar rod works well for this, because it has a rough surface which grips the vertical strings & prevents them from sliding. I route the rebar through PVC T's placed on top of the poles. For heavy vines like limas, I would recommend 1/2" rebar. A rough piece of wood would work as well, provided it is thick enough to bear the load of the full grown vines without breaking.

10' is a tall trellis, with a large wind signature - especially when covered with dense vines like limas. Even deeply driven poles might not withstand a good thunderstorm without being toppled. Depending upon the length of the row, you might need more than just two poles. If the trellis is exposed to strong winds, you will definitely want to brace the poles somehow. It is so disappointing to have a trellis full of developing pods, only to lose it all to a strong storm... I know that from experience.

I would recommend hemp or sisal baling twine for the verticals, and avoid cotton. Cotton tends to rot or weaken in a wet year (or if irrigated overhead). Some of the strings could fail when weighed down - again, this avoids disappointment. I seldom have that problem with baling twine.

Good luck with "Big Mama", those are some impressive limas!

Hi Zeedman,

I noticed on a Bill Best video that he was using white twine. Is it possible that this would be a bleached natural fiber or could it be plastic bailer twine? Has anyone tried plastic twine and used if for more than one year? - Dick

zeedman, I never had the problems you had (as of today), but see that your system works better for many reasons.
Thanks.

Zeedman,
Thanks for your very informative post. We had planned on bracing the posts but had not considered how the verical strings might slide on the upper horizontal string. This will be our third year of experimenting and learning about gardening on a different level. We are both big lima fans, but our bush crop last year was a bit disappointing. Planted Burpee Ford Hook 242's. The only plants that did really well were the ones that could lean over on the fence at the end of the rows or on some other plant. Rather disappointing. We hope to solve that problem with the big mama's, and also increase our yield by using a pole variety. It's still a small (expermental)garden, only 12x14. One row of Blue Lake Bush, one row of Big Mama's, 22 Bell Pepper plants of assorted color and variety. And yes, we both like growing peppers! The first ones sprouted in the seed tray in the last couple of days. The peppers will stay until the end of the season, but we will pull at least the Blue Lakes mid season and try some other type of bush bean or pea. Leaning towards trying peas, but still trying to decide which one would be best suited to start in our zone (7) mid season.

Just out of curiosity... were the Fordhook 242's producing pods, but rotting where they touched the ground? I had that problem when I grew them. Still got a fairly good crop, though, and if I ever choose to give up pole limas, they would be the variety I'd grow.

Yeah, me give up pole limas... like that will ever happen! ;-)

Drloyd & Jolj,

When I gardened is SoCal, I used cotton twine for trellises, and swore by it. In fact, I recommended it (along with other natural fibers) for pole beans, since some are reluctant to climb artificial supports (especially yardlongs). Rotting was not a problem for me there, and those who garden where summers are fairly dry would probably have similar results.

But when I first moved & began gardening in the much wetter climate here, I had quite a few cotton string failures late in the season - when the vines were at full growth. My trellis design has redundant support, so the vines didn't collapse completely... but I switched to natural baler twine for verticals after that. It is sold in several grades here at the local Farm & Fleet, varying in thickness. The smallest grade will occasionally fail toward the end of the season too, so I use the medium grade, and have had no string failures since.

Since the grade of the string/twine had something to do with its tendency to fail, its possible that a heavier grade of cotton string would be just as effective. I haven't seen the Bill Best video, but I wonder if he uses a heavier grade, or a synthetic or cotton/poly twine.

It's been quite a few years since I used cotton, and don't remember how thick the string was. I know there were not many choices available at the time, and it came in fairly small balls. It was also pricey for the amount that I needed - another reason that I switched to the more economical baler twine. Keep in mind, though, that I put up about 500' of trellis a year. If you only have a few feet of trellis each year, a roll of baler twine would probably last for several generations. ;-)

Dick, I also use plastic baler twine in my trellis system, for several horizontal strings that run between poles & tie them together (that's part of the structural redundancy). I tried to re-use it one year, but found the process of removal to be too time consuming, given that the twine itself is so cheap. It looks to be strong enough to use for multiple seasons, though. Some years I don't get to tear down my trellises until late Spring, and the orange plastic twine shows little sign of deterioration. In contrast, the organic twine has pretty much fallen apart by that time.

Oh, a curious note about that. When I don't remove the strings until Spring, I notice that the bottom foot or so of most of the vertical strings is missing. I can only speculate what is doing it, but my guess would be that the voles (or rabbits?) have made themselves some very comfy Winter accommodations. ;-)

Zeedman thank you for the informative post. Your posts could be compiled into a first class guide to growing legumes. I do have a rather long Word file of them!

I have about 300 feet of trellis and as you know it takes time to put up the twine each spring. So I was wondering about using a UV resistant plastic that should last a few years. That would make removing the vines more difficult as with jute I can just cut the twine top and bottom. With plastic I would have to untangle the vines from the plastic in order to leave the plasic in place.

If I understand correctly, you tried that and it took too much time. - Dick

No one has mentioned trellis netting & it works well and lasts several years, though I am not doing long runs as some are. Mine are left in place at ends or sides of raised beds using junk wood for posts & one crossbar at the top.

It occurs to me that this discussion probably should be on the trellis thread, but since the OP did mention support...

..."With plastic I would have to untangle the vines from the plastic in order to leave the plastic in place... ...If I understand correctly, you tried that and it took too much time."

Although I do not leave my trellises up from year to year, I did try to recycle the twine once, as well as to leave all vines in the garden to be tilled under. If the vines were left on over Winter, they were dry & brittle by the time I removed them in Spring. I would cut the bottom of the vertical string, cut the base of the vine, and cut any tops that had grown beyond the trellis. Most of the time, I could then pull from the top down, and the vines would slide off. It took practice, and some varieties were more difficult to remove than others.

But in the end, with the wife & I both removing the vines, it took several days. The weather is fickle here, and I don't usually get the luxury of that much time; so I decided that my time was worth more than the cost of the twine.

I've actually been wanting to change my trellis system, to reduce the time I spend each year erecting them. I have thought about 5' tall concrete remesh, cut into 5' & 10' lengths & attached to the poles with zip ties. The different lengths would be combined as needed depending upon trellis length. I already use zip ties for attaching the bottom support, so I know they hold up pretty well. SSE uses basically the same system on their farm, where they use thousands of feet of trellis.

But there are two drawbacks. The first is that to get the lengths of remesh I need, I would need to cut my own from the 150' rolls. Sounds easier than it really is. The wire is fairly heavy gauge, and after you cut it, you then need to bend it straight... which is also difficult & time consuming. I have 2 rolls now, and might get this done eventually... but it will be a lot of hard work to turn those rolls into flat panels.

The other problem with using steel for the trellises (whether remesh, fencing, or cattle panels) is the storage issue. Because of my crop rotation, the trellises will be in different places each year & must be removed before Spring for tilling. As it is, after Spring cleaning, I have to make piles of poles & rebar rod off to the side of the garden. That much remesh (or steel fencing), when stacked off to the side, would be a real eyesore. My main garden is on a friend's property, so that is out of the question.

"No one has mentioned trellis netting & it works well and lasts several years, though I am not doing long runs as some are."

I considered it in the past, but found it cost prohibitive. Also, although it might last several years, you have to clean all of the debris out of it after the first year in order to reuse it. While that might work for small runs, it would be nearly impossible to clean off 100' or more in a reasonable amount of time.

Oh, and on the topic of cleaning trellis material, there is an easy way to clean old vines from wire fencing. Just roll up the fence - vines & all - when everything has dried, and (in a safe place) set fire to it. Presto! no more vines. Cool, unroll, and reuse.