I was culling some persimmon rootstocks that have repeatedly rejected grafts, and took the opportunity to examine their root systems. They were in 4x10 Treepots and Anderson Plant Bands. Both seem to produce a nice root system, but there are some clear differences. Plant band is on the left, treepot on the right.
First up is the Treepot. This one had been in the same pot for 5 years now (but cut down twice for grafting). Nicely branched root system, not really pot bound. Definitely a bit of coiling at the bottom, but nothing that couldn’t be corrected at planting.
Next is the plant band. This tree has been in this pot for two seasons. Also nicely branched. You can see how the bigger openings in the bottom very effectively prune the roots and prevent circling. This results in a heavy mass of branched roots in the bottom 3" of the pot.
Granted this is a small sample size, but I’m impressed with the performance of both containers. I’d give the plant bands a slight edge overall, but I’ll probably continue using the treepots for now. They’re easier to obtain in the quantities I need, and still do a good job.
These results also reinforce my notion that anything deeper than 10" is overkill for persimmons, so long as there’s some level of air pruning and decent soil volume. Considering the one in the Treepot had been in there for 5 years with only minor root circling, that’s pretty dang good.