Can you prune the oak to give the hackberry more light?

Prune the heavy side to lighten the load, and start planning a replacement for that tree, because it will keep leaning.

I wouldn't want one of these on my property. They are the ultimate "trash tree." They scatter seeds over a wide area, causing jillions of little hackberries to spring up. The wood is also soft, brittle, and rots easily, making the tree dangerous for children to play under. It will eventually get huge, increasing the cost of removal. I would replace it with a Monterey oak, in Central Texas. If you must have shade quickly, you might consider the much-maligned Bradford pear, but educate yourself on how to shape it, to keep it stable.

I wouldn't attack the oak for the sake of a tree that should probably be replaced with another, planted farther away from the oak anyway.

Pruning the oak is not really an option since it would be out of balance as a result. And I'd rather have the oak over the hackberry.

As it turns out, I'm already starting some replacement trees for another reason -- namely several of our oaks got oak wilt and died. This makes the decision about cutting the hackberry down rather difficult. If the big oaks die from the oak wilt, the hackberry will be the only major tree left. But it is starting to look like a hazard. My concern is the first heavy, saturating rain will loosen the roots and it's going to fall over.

I'm starting to grow some paulownia kawakamii trees to replace the dead oaks. I'm not sure how the paulownias are going to do in the soil around here. If the paulownias look like they're going to take off, I'll ditch the hackberry. But that will be a couple of years from now.

a tree that is growing out from something.. in search of sun..

is NOT 'leaning' ...

without a pic.. me thinks the tree is doing its job..

and you are thinking it is a 'problem' ...

me thinks that the problem is.. that you dont like the look.. an aesthetic issue.. rather than a tree issue ...

i would never touch an oak for a trash tree like hack ... i mean really... its name says it all ... lol .. get rid of the hack

ken

The Hackberry at some point will fail. They usually have a short life. I would probably prune one or two of the larger limbs each year to lighten its load somewhat. We have several in the back that we have pruned and left for shade. They will do better and last longer if pruned and competition is removed. While I wouldn't plant one, if one is there and useful, I would tend to work with it for a while unless I was afraid it falling would damage something.
My wife has planted a paulownia tree (Waco area) and it has done ok, tho it is not as pretty as she had hoped. Personally, I wouldn't plant one, but my inclination is toward native species.

I'd love to replace my oaks with new oaks which are the prime species here. But I don't think I'll live to 150 to see them grow. Also, I'd be reluctant to plant oaks given the oak wilt in our area. Diversity seems like a better idea. Juniper (mountain cedar) is also native, but they are not pretty and a real nuisance. They will also suck all the water out of the ground. The paulownia was chosen for it's fast growth and drought resistance. Getting some shade from the south texas sun is welcome as well.

I know about hackberry's short life. There is one in my backyard that's probably around 75yo. It's starting to go one limb at a time. That one is going to be a problem to remove due to it's location.