Rebar steel rods for climbing plants - rust protection?

Moin everyone,

After my first DIY climbing help for peas collapsed under the weight of the green masses, I swore to make it better the following year.

So now I bought a bunch of rebar steel rods (length 150 cm, diameter 10 mm) in the hopes of using them to build my own climbing aid for plants like peas, small bushy beans and others that need a little bit of support. The rough pattern on the rods seems really helpful to give them a good grip.

My question would be the following:
Do you have any experience using rebar rods for plants? Do I need to protect them from rust (e.g. painting them) because they will be outside for the better part of the year. About one third of the length even beneath ground.
Or do they live long enough in those conditions, so that paying 1-2€ per piece every X years is the better investment?

 

I've used the thinner rebar as climbing support and only painted them for aesthetics. It doesn't need to be an expensive brand, anything that can be used on metal.
I used black because it matched the side gate and ornamental lamp post(and it's the colour I had)

 

I don't plan on installing them permanently. Nor do I want to weld the together into a bigger structure.

My hope is to use them as a kind of "modular building kit" together with a little bit of wire. Then, after I harvest whatever was growing on them, I disassemble them and they get stored in the shed for the next season

 

I got similar diameter iron bar sections from a builder's providers to be used as hoop supports for netting to protect crops almost 20 years back and they are still OK to use. They are rusty on the surface so I wear gloves handling them but they have been outside in all sorts of weather for all that time with no protection. I think when I used them one year to support climbers I strung string between the iron bars to cover the area better.

 

I've got a few lengths and the rust colour actually helps them to blend in.
Unlike a few lengths I acquired from where I worked years ago, which are stainless steel.

 

I doubt they are stainless, but I think I will leave them as they are now.

I'm using gloves anyway whenever I work in the garden, so I don't cut myself.

May they rust in peace and hopefully I won't see them anyway because of all the plants growing around them

 

Oh they are stainless steel it was all bought in specially for making reconstituted stone work.
It's been outside for years and still bright silver.