eco friendly and safe alternatives to treated wood as vineyard poles

I am considering establishing a grape vineyard in my small plot in semi-mediterranean climate. I am looking for safe and aesthetic alternatives to using pressure treated wood as poles. Preferably I want to use wood instead of steel, plastic, or concrete. But untreated wood is known to rot in a few years. However, treated wood causes some concerns for me.

Are there any alternatives that you may recommend? Or are you aware of any research that indicates the degree toxicity released by treated wood?

Thanks,
Oguz

the best ive ever seen were steel I beams with galvanized wire from from to rear of each row of vines for trellis. looks a lot like a cloths line. do it once and it will last a lifetime. unless you want to not use trellis and prune into bush like they in Europe quite often
if using wood I guess cedar, cypress or like orange osage or other type of wood that resists rot and bugs  would work best

Redwood would make great posts if it is available or not too expensive.

My 2nd choice would be cedar.

As Bruce said, "cedar, cypress or like orange osage", would also be good choices.

Add oak and chestnut to the list of timbers that weather well. They may also be more available in a Med-esque climate.

There are a lot of discussions about this general topic on the forum, but not so many specifically about vineyard poles. Searching for "untreated wood fence posts" brings up a lot of these discussions as fencing is a more common problem.

Generally speaking - wood breaks down over time, and we like that because it returns its nutrients to the ecosystem.
A lot of treated wood contains arsenic which makes it harder for bacteria and bugs to break it down, but they will still do it over a longer time, but in these cases releasing that arsenic into the local ecosystem.

Arsenic is present in ecosystems at a low ambient level, but the amount in treated wood can be dangerous if in very close proximity to human food producing plants. Different plants take up arsenic in the soil in different ways and in different amounts. But in the long run it's not something we want in high concentrations in a garden, field, or vineyard.

So, if you're set on untreated wood then you want something that has a natural resistance to bugs and bacteria and many of those woods have been suggested. You will have to replace the wood when it breaks down. So you would want to design your poles in such a way that replacement was a relatively low maintenance task.

Alternatively use another material.

I got my information mostly from this article: https://extension.psu.edu/environmental-soil-issues-garden-use-of-treated-lumber

Old treated wood may indeed have the aresenic treatment CCA. I wouldn't use it anywhere near food growing areas, since there are issues with uptake into plants.

The current treated wood available to consumers (here anyway) is treated with a different copper based material, and a tag is stapled to each piece. It is supposedly much safer in food production and playground areas.

EDIT: pardon my ignorance, but what sort of trellis is needed to stake grapevines?

I would strongly urge use of wood posts along the lines of what has been suggested, depending on what you have available. Trees in the juniper/cedar group last for decades. Another one ranchers in western USA use is black locust. There was a very interesting experiment done here in the western U.S. that looked at the life of posts of various compositions: different species and different treatment chemicals. Some species can be expected to last 30 or more years without chemical treatment. I've previously found the experiment's results searching on Google, but could not replicate that success just now...

My parents planted a vineyard back in 1988 using steel t-posts at each vine and a black locust post at each end. The trellis system was a simple high-wire, with canes pruned to the wire, and shoots allowed to simply trail down towards the ground. It would also have worked fine with VSP or really any other training method out there that uses rows. Every year I would replace maybe 2 posts, out of 150. That probably only started about 20 years in, and by the time I moved on to other projects, there were plenty of posts that had been in the ground for 30 years. They were still so hard that if you didnt pre-drill, a sturdy u-staple would just wad up into a mangled mess. The oldest vineyard was just pulled out this spring, as the vines were getting diseased. The t-posts would probably have been good for another 30 years.

So yeah, black locust is amazing wood. I planted a few hundred trees about 7 years ago, and I think it would be possible to have pole-sized trunks in about 10 to 15 years. They grow really fast, and they also fix nitrogen, and come back when you cut them. The negatives are that they have the most god-awful thorns I have ever seen. The wood is also hard to work with, as I mentioned; you need to drill for every nail or it wont go in. And this might not be relevant to you, but around here we occasionally get freezing rain that will coat trees in a thick layer of ice. This last spring it was terrible, there was half an inch of ice on everything. About half my locust trees simply fell over.