Grapevine deadwood or live vein?

[Vali]

I have some decades old grapevines and I'm trying to find which parts of the trunk are dead and which are alive. Some parts look dead, but after scratching, I saw they were alive, other looked alive but were dead. Different parts have different colours, but I find it really confusing. Is there a better way to differentiate them except for scratching the entire tree? Thank you.

 

[Wires_Guy_wires]

The layer of live material in grapes is so thin that I found it the easiest to strip old bark when they're actively growing. At that time it gets a little thicker. But it's still difficult.
Good luck! I hope your grape isn't the same as the unrooted trunks they threw into buckets here, because those give up after a year.

 

[Vali]

The layer of live material in grapes is so thin that I found it the easiest to strip old bark when they're actively growing. At that time it gets a little thicker. But it's still difficult.
Good luck! I hope your grape isn't the same as the unrooted trunks they threw into buckets here, because those give up after a year.

Thank you for your reply.
I have 4 and they are all alive. I collected the most recent ones last spring. One of them was exactly an unrooted trunk in a bucket, but it survived somehow

 

[Wires_Guy_wires]

unrooted trunk in a bucket,

Old trunks can live two years without roots before succumbing, so my advice is to not invest too much into that one until you see visible root growth.

 

[Shibui]

Some parts look dead, but after scratching, I saw they were alive, other looked alive but were dead. Different parts have different colours, but I find it really confusing. Is there a better way to differentiate them except for scratching the entire tree? Thank you.

It's not clear how you are searching for live and dead sections. Also not clear what you think indicates live and dead sections.
In my opinion you have not gone deep enough to work out whether that bark is alive or dead in the pictures supplied though there are some obvious dead sections in some pictures they don't appear to have been scraped.

 

[Vali]

Old trunks can live two years without roots before succumbing, so my advice is to not invest too much into that one until you see visible root growth.

I didn't think at that. I looked at the bottom of the containers and they have roots escaping. Seems that I may have been lucky.

 

[Vali]

It's not clear how you are searching for live and dead sections. Also not clear what you think indicates live and dead sections.
In my opinion you have not gone deep enough to work out whether that bark is alive or dead in the pictures supplied though there are some obvious dead sections in some pictures they don't appear to have been scraped.

I made very small scratches in different places on the trunk, they are hard to find even if you look directly at the tree. I don't think they are visible in the photos. On the rest of the trunk, I just peeled the bark, trying not to go too deep, because I don't really have experience with this procedures and don't want to hurt it. I tried to find the differences based on the colour, but wasn't succesfull. I will probably notice it in time.