Just one of those things. The graft may have been dodgy in the first place causing weakness and issues with water transport withing the plant. And the species would be more vigorous by nature than the cultivar. If anything causes the scion to struggle the rootstock could overtake it. Alternatively it was missold in the first place. We cant see the base of the plant in your picture so we don't know if there is evidence of a graft.

My 'Twomblys' is in full sun and fries every year during the first (and any subsequent) heat spells. I'm either going to find a shady place to move it to or just get rid of it. It's a nice tree, though. I plant almost everything on mounds; I scratch/dig out a shallow depression, tease the roots apart and set the tree on the depression, and make a wide mound around it. Sometimes I just dump (read: have someone else dump) a few yards of soil to make a large mounded bed and then plant it that. My mounds are made of a mixture of amended loam (the highest mineral/lowest organic mix that I can find) and 1/4" red lava rock, no fines. I usually use a 65-35 mix, although when I am planting Australians and succulents, I do 50-50. Conifers do great in either mix. This allows for good drainage and enough structure. Eventually many of the tree roots make it down into the native soil, but if I start them there, level with the surrounding ground, they struggle. And Ken is right - local conditions make all the difference. I read with interest many posts here and elsewhere about issues and problems growing all kinds of trees that we don't have here in conditions that we could never hope to emulate. I couldn't possibly offer any advice!

Oaks don't 'like' to be forced to do anything. - staking a tree that size will be remarkably unproductive - the current lean will never be enough to cause it to fall from it's own weight - the crown will even up but that section of trunk will retain that lean Looks like a Live Oak? It's not a tree with a long central leader anyway so the current form will evolve into a form that you'd note as typical for the species (ie. not having a long straight dominant leader).

That's a great looking tree Dave, thanks for sharing! It looks very happy. How old is it? I'm encouraged that lower limbs will sprout within the next year. I have a Meyer lemon and this Ruby Red grapefruit. Both are new to me this spring, so I've never enjoyed the eventual fruit crop. Everything I've read is that citrus love sun all day, especially if you want them to fruit, but Phoenix has brutal summers, so maybe less sun is okay? Then you add in the container factor, and I just don't know what to expect. It's hard to tell from the pictures I posted, but my grapefruit has several large leaves attached directly to the trunk below the limbs. These are the largest leaves on the tree (so I assume they are the oldest). I've never seen leaves attached to the trunk instead of branches. They are also kind of droopy, which I initially attributed to "sulking" due to location change. But they haven't lifted up yet after a week, so maybe that's just how they are. Is it normal for the trunk to grow leaves?