So if I'm seeing that right they are very small containerized potted trees? Not bare root?
I've planted quite a bit of trees/shrubs over the past 5 years (not 1000s like some have, maybe more like 40-60 per year). Because I've staggered it out I've mixed up my exact planting type/style/caging/tubing/etc.
I will say that my trees in tubes grow much quicker than those not in tubes. That said, my deer have learned that tubes = food. ...and tubes = crinkly loud noises that the young bucks really love in the fall. So a bit of a catch 22 because my deer now "target" the tree tubes. Even some understory trees (paw paws) that I have scattered through the understory and away from any noticeable deer travel routes. Also be warned that wasps like to build nests inside the tree tubes. Not a huge deal, but the raccoons LOVE wasp larvae. They will climb up the tree tubes until they collapse and then try to fish out the wasp nest.
To that end I would HIGHLY recommend that you stake the tree tubes with PVC. In some early iterations I used the bamboo stakes and they do not withstand the full on assault (or even a half-hearted assault) by a yearling buck learning the joys of rubbing his antlers, nor will they bear the weight of a fat ass coon.
I have used
Forestry Suppliers for tree tubes in the past and have been very happy with the results. Then I just buy 1/2" PVC from a local store and cut it as needed.
I will say in general that you are better going 1 foot taller than you think you need. Also, understand that the tree tubes will cause faster upright growth of the tree, with the height outgrowing the lower stability. In other words you'll need to keep the tree staked for quite a while. It'll be too tall and weak in the lower trunk to survive any kind of decent wind storm if you pull the tree tube/stake after a few years. You should really leave the tube in place and allow the tree trunk to grow out and "fill up" the tube before it is removed.