What is the smallest diameter for a tree to safely hold a lock-on stand? I am thinking of putting a king-kong lounger on a tree that is only 33" in circumfrance. I have to do this because it is the biggest tree downwind from where the deer will be enterning my food plot.

33" in diameter is a nice size tree. I have had climers and hang-ons on trees that are only 15" in diameter. You should have no problem with that size tree as long as the tree is living and does not sway too much when you get into it.

Do you mean circumference?

Sorry!! My tree is 33" in circumference.

A tree with a circumference of 33 " isnt that big especially for a stand the size of a King Kong Lounger.You can do it more comfortably with a small loc-on but stay away from the windy days.
Have you considered using a ground blind like the double bull in your food plot,considering the trees are limited?
Another idea is to make a permanent tree stand using 2-4 of these trees or a ladder stand.

I really want to get up in the air, do you think a good ladder stand would work on a tree of that size?

A good ladder stand of about 12-15 feet would work great in the tree.I usually put my stands about 20 feet off the ground.
A ladder stand would also work great if you put it up to 2 trees side by side.Maybe making it a little sturdier on the windy days.
Good luck

P.S----try a small stand in the tree first,try not to go to high up as the tree is getting smaller and weaker as you climb.If you can safely get to 15-16 feet go for it.Only thing I would suggest though is to stay out of the wind and only hunt it on calm days.And please wear a safety belt.

thanks for the tips

That tree is about 10.5 " in diameter.

I have never seen a tree break from a human that was that big.
Go for it. Just make sure that you have some good "back cover" Use some good ratchet straps to secure it like a rock.
I'm in trees all day that size. You will have no problems!

Most lock-ons I see advertised say they will fit any tree from 8-20 inches in diameter. I know I've been in some so small that every time I moved, the entire tree would sway. I never felt unsafe.