No, you can trim off thorns, will not hurt the plant. What citrus cultivar has such wickedly long thorns? That sounds more like rootstock to me, and not an edible citrus cultivar. I would check to see if you can see a visible graft line at the trunk. If not, your citrus tree may have died, and all you have growing now, is the rootstock. Again, photos are helpful.

Patty S.

a few pictures of the tree and of the base and trunk would help.

although my N-33, Cara cara and Moro blood orange trees all have some long thorns from 1" to 1.5" long.

I planted a navel orange tree 2 years ago and it's bearing a few oranges this year. About 2 months ago a branch sprouted off the main trunk above the graft and has long thorns on it and is growing very aggressively. It's already taller than the rest of the tree. Photos are attached. From the other postings it appears I should not prune it off. Does anyone have any advice after looking at the photos?
Thanks

Maybe it's a sport? Hopefully it will fruit soon and you can tell what you have.

Fast-growing water sprouts are often quite thorny, aren't they?....even on a mature tree?

Water sprouts are naturally thorny, big vicious thorns.

What are water sprouts? And what should you do about them?

Navels grow low to the ground. It looks like a vigorous low growing branch with thorns on it.

My Pomelo seedlings have developed some impressive thorns.

Josh

I have to agree with Patty . I have a few trees with very high grafts . If you can take a picture from the other side of the tree we might be able to see the graft line better .

Brian

I could be wrong but doesn't it look like the thorny branch is growing from exactly where the graft scar was? Zoom in on the photo a bit.