Huh? Let's just set aside the viability of this project and my inexperience for a moment. What you describe sounds more like an ordinary containerized tree. Assuming full "bonsai" style root pruning, wouldn't a pot be more somewhere in the order of 8:5 ratio (tree ht:pot length) and 10:1 (tree ht:pot depth)? (I've been measuring various images of upright conifer bonsai... )kdodds wrote:I don't think the difference between a 5 and 6 foot tree is going to be all that much in terms of an appropriate pot, ... Conservatively, I'd say the five footer would need something on the order of a 30" cube, but that's being very generous.
Hopefully, for a 5 ft tree, that would bring the pot size down to around 3ft L x 10" D oblong pot, OR somewhere around 24" diam x 10"D round pot when finished.
In fact, I'm leaning towards a B&B tree rather than a containerized. This way, initial root pruning would be already done, and my first year challenge would be to pot it up in proper planting medium (having first removed all existing soil ) and keep the tree alive. Thereafter, I would imagine the depth of the root ball would need to be reduced at each late winter/early spring repotting until the desired shallowness is achieved. If it's an ultra hardy species (like hardy to zone 3) I wonder if it could be root pruned/tip sheared again around late August as well here in zone 6? I'm thinking hardiness to least zone 4 at any rate.
So far, I've found a 15 gal rubber feed pan (26" diam x 9.75"D) for $20 (those puppies are heavy though, and floppy/flexible which maybe a problem. On the other hand, a couple of old gratings from a kettle grill might provide a support structure inside and, supported on brickes, a draining surface for the pot (with holes in the bottom of the pan of course). 15 gal wash tub ($32) is a bit small at 21.5" diam x 10.25"D and 17 gal wash tub ($36) is just a bit smaller at 23.75" diam x 10.75"D.
Also I was watching a youtube video https://www.youtube.com/watch?v=yEYQyCW9Gnw and I swear his bonsai is planted in a baby bathtub! I rushed out and measured the one I have in the garage and it's about 20" long, which, by my calculations, is good for a 32" tall tree. (Yes, yes, HIS tree is 24" tall at most)
What can I say, this is the way I treat all new ideas
p.s. This is a really interesting read although the subject matter is deciduous trees -- this is giving me a new insight re: B&B vs. containerized
Here's the abstract -- download the pdf or google for it to read the rest of the paper:
NURSERY PRODUCTION OF TREES IN CONTAINERS
by William Flemer III
P.O. Box 191
Princeton, NJ 08540
ABSTRACT. --The possibility of growing sizeable shade trees
(1%" and over in caliper) in containers is exciting to
both arborists and nurserymen.
Advantages include reduc-
tion in transplant shock, ease of retail storage, exten-
sion of the planting and shipping seasons, and less need
for nursery space.
However, problems include difficulty
in overwintering in northern climates, root girdling,
potbound trees, and the high cost of growing mix and
The suggested best method for cold-weather
zones is to re-establish large trees in containers.