If I understand what you are saying, you have a stub left at the top of the central trunk. Is that right? If so, no, you cannot graft at that point because the tissue is dead or has at least lost most of its vigor (if the area is green and possible has some small branching growth) if the cut is not fresh (which you said it wasn't). If there is live branching left near the top of the trunk, you could could recut, below that growth, and graft there. A picture of the area in question and of the whole plant would sure be helpful.

Now the big questions...you mentioned "the main" trunk. Are you wanting to grow your plant as a tree with a single central leader instead of as a shrub. There are advantages to growing them as shrubs (easier picking, continuation of plant after single trunk loss, less worrying about suckering, etc). I remember seeing a good video on pruning and growing pomegranates, but can't seem to find it at the moment. I thought I remembered it being one of Dave Wilson's videos, but could be wrong. Maybe someone knows the one I'm thinking of.

Next big question...is there a reason you want to graft onto the existing tree instead of growing a second plant? I would imagine, if there is, it's probably a space thing, but you can grow a pomegranate in a relatively small area. There are numerous advantages to growing another plant, if that's an option.

And a small, but important question...where are you? Climate is going to make a big difference in what you can grow and even how your plant can be grown best. For example, in colder climates, bush-form pomegranate plants may have an even bigger advantage over tree-forms.

I am located in San Diego, CA.

I am looking to graft because space is a concern. I only have space for a few pots, and the rest are currently full, so I figured growing a few different pomegranates on one trunk would be a good alternative.

The tree is fairly small, which is why I was thinking of trying to utilize the main trunk. I forgot when I asked my question that there is a branch growing out of the edge of that old cut.

Do those two branches look big enough to handle a graft?

Do pomegranates do well with bud grafts?

Thank you for your help

This is a little closer shot of the top cut

Oh WOW!!! I sure had the wrong picture. When you said a pomegranate tree, I had pictured a very large specimen that had been trained into a decent-size tree over the years.

I think your pomegranate rooted cutting will very quickly outgrow that pot. Even here in zone 6/7, a pomegranate will grow into a big 6' ball in about three to four years. It will also start sprouting lots of suckers in a short time.

IF I were going to try to graft another cultivar onto that plant (which I wouldn't do), I'd wait until it got larger and try to graft onto a main limb or trunk (depending on whether you try to keep it pruned to a single main trunk or let it become a more naturally growing shrub form). Either way, if you are going to keep your pomegranate in that small of a space you are going to have to practically bonsai it. You are in for lots and lots of regular pruning (top and roots) and repotting. I don't mean to sound so discouraging, but I also don't want to give you false hopes.

Yeah, I'm so used to working in my small garden I forget to mention I'm on a smaller scale than most people are used to/thinking of. Thanks for the advice, I guess I'll hold off for now.