Container Wars

[Gabler]

What type or types of containers do you use for trees in training? Why?

I’ve lately been using growing bags myself, since I wanted to experiment with air pruning, but many of you use colanders, wood boxes, ceramic training pots, plastic nursery cans, Anderson flats, etc. What do you tend to reach for by default? Is there an optimal container for your climate? Do you consider any of the options I listed to be suboptimal or outright bad?

Here’s an ironwood (Carpinus caroliniana) in a growing bag, just because I feel like every thread should start with a picture. Note that I’ve folded down the sides to make the bag more shallow.

 

[BobbyLane]

How do those bags hold their shape? Id be concerned about damaging roots, when moving those bags around.
I tend to use plastic tubs, or whatevers at hand really, sometimes oversized bonsai pots, cut down nursery tubs, washing up bowls

 

[LuZiKui]

I pretty much use all of those options except for grow bags. And it's no fault of the efficacy of grow bags, its just that I'm cheap

I've got my pines and olives in pond baskets from depot/local nursery. I have some trees in cut down nursery cans. And I've also started making boxes for some of my larger trees. I've said this elsewhere but I'll look in the back of the home depot where all they put all the discounted bad wood. A lot of times they have a bunch of cedar/redwood fencing that is a little too curved for a fence but perfect for a grow container. 70% discount and those planks are like $1.50, so I can make a grow box for $1-$2 with wood, screen, screws, etc.

So like a lot of my bonsai decisions, whatever is cheapest/easiest/most readily available, in some order.

 

[Gabler]

How do those bags hold their shape? Id be concerned about damaging roots, when moving those bags around.
I tend to use plastic tubs, or whatevers at hand really, sometimes oversized bonsai pots, cut down nursery tubs, washing up bowls
View attachment 482291View attachment 482292View attachment 482293

They hold their shape as well as any thin plastic nursery pot. Once they fill with roots, they’re very firm. I can’t say I’ve noticed issues with root damage after the trees are established. I’m somewhat careful not to squish the bag if moving a newly-potted tree, but there’s seldom any reason to move a newly potted tree. Accordingly, I can’t say I’ve noticed issues with newly-potted trees either, but that could be due to my additional caution.

 

[Gabler]

It seems I neglected to include pond baskets in my list of container options.

 

[Cruiser]

For collected trees, whatever’s nearby that they’ll fit in, with not too much extra space. For recovery/growing, not showing off.
This includes costco storage tubs, cheap wooden crates, milk crates, pond baskets, plastic feed bins, etc with lots of drilled holes. Also screwed together wooden flats made with 2x4s etc and 1/4” hole chicken fencing stapled to the bottom.
I’ve seen some collected trees that have sat in black trash bags for who knows how long.

I’ve had good experiences with Anderson flats. Both the wider flat versions and deeper square sizes. I consider them a bit more presentable than some of the other mentioned containers and a step in the right direction when reducing roots on the journey to a more presentable pot.

I’m not a fan of thin-walled black plastic nursery pots but will keep nursery material in them if out of repotting window. My experiences have shown them to be poor insulators of roots, not just in winter but in our hot dry summers. If possible I’ll put them within larger ceramic pots to provide better insulation.

No experience with grow bags…

 

[Gabler]

The gist of this thread seems to be “whatever is lying around,” but I know I’ve seen at least one thread about sourcing Anderson flats. Is there anyone out there who strongly prefers a specific type of container?

 

[BrianBay9]

I prefer to use pond baskets. I don't like grow bags because I know I'll move trees around throughout the year and they are hard to move without disturbing the roots.

 

[Cruiser]

I prefer Anderson flats. No need to add mesh underneath. Many hole options in which to feed wire through when securing a tree or guying. No issues with sitting water in bottom of pot. Bottom roots get air pruned, but if the flat gets placed on the ground or substrate, tree roots are permitted to escape all across the pot, not just through a few holes.

 

[Tieball]

Wooden boxes because they hold up well in my environment, insulate well in my winter where they are left outside, and the boxes don’t blow over in the wind. I maintain smaller size boxes made to fit my needs, however, all my boxes are generally the same size. In the boxes I can plant as low or as high in the box as I want. Easy for guy wire attachment.

 

[Orion_metalhead]

For grow out, I make boxes out of pallet wood. Pallets are usually free and other than some screws, theres not much cost if you have tools. If they break apart or rot, no big deal, i just plan to make another. Additionally, you can make them so you do not need screening by leaving 1/8" gaps in the bottom planking. Soil typically doesnt fall out if you screen to that size. I can get as much crate wood for free as I can handle through work when we get shipments of crated equipment and my boss just usually tosses it.

I use smaller quart sized nursery pots once cuttings have taken/seeds have germinated.

I move to nicer pots once I feel the tree has a structure set and the majority of root development is sorted out. I dont kind slow growing the trees.

 

[LittleDingus]

What type or types of containers do you use for trees in training? Why?

I’ve lately been using growing bags myself, since I wanted to experiment with air pruning, but many of you use colanders, wood boxes, ceramic training pots, plastic nursery cans, Anderson flats, etc. What do you tend to reach for by default? Is there an optimal container for your climate? Do you consider any of the options I listed to be suboptimal or outright bad?

Here’s an ironwood (Carpinus caroliniana) in a growing bag, just because I feel like every thread should start with a picture. Note that I’ve folded down the sides to make the bag more shallow.

View attachment 482268

I predominantly use grow bags...I have a few as large as 15 gallon. I often fold them over as well

A well rooted tree holds its soil solid. I mostly use NAPA 8822 with some chunky coconut coir or fir bark. The root bags get solid as rock as the tree establishes.

The "air pruning" is a myth. I still get circling roots on everything. This is my latest extraction from a grow bag: a 4 year old dawn redwood. This is after being in a 5 gallon folded over grow bag for two years.



Some of those curlers were 3' long when combed out. I've used true air pruning pots. This doesn't happen in a true air prune pot.

What does happen is the fine roots knit themselves into the weave. I've never had one escape...but not what I would call "air pruned" either.

I'm probably going to stop using bags bigger than 5 gallon. I've had many of the bigger bags rip due to the weight. I'm sticking with the smaller bags though because they are very hard to overwater, they're reasonably cheap...I get 5 years out of the smaller ones easy and they fold up to take less space in storage.

 

[JackHammer]

I have been enjoying bus tubs lately. Large, relatively shallow and plenty of room. I use terracotta large azalea pots for a lot of things. I can bring the smaller ones inside in the winter. Otherwise, I will slip pot into something plastic when the fall comes.

 

[proninyaroslav]

If there is such an opportunity, then I prefer to use a mesh container. I have appreciated their excellent functionality for forming a dense, fine root system, without annual repotting and root pruning. Such a pot dries faster and less frost hardy, but its pros outweigh the cons, I think.

 

[JeffS73]

I've used grow bags, and the 1 litre ones are fine. Above that, I can't easily push a plant out, and have to cut the pot, which makes it either single use or I stitch it with garden wire and reuse which is a huge waste of time. Also as others have said, unless you suspend them, you still get circling roots.

I've moved to pond baskets from 1L to 4L/8L (1gal/2gal). Above that, boxes.

 

[Wires_Guy_wires]

Is there anyone out there who strongly prefers a specific type of container?

I don't like bags because the soil shifts when moving them. Relocate a plant and you might kill it.
I switched to cheap terra cotta candle containers; wedge out the candle, drill a hole and you're done. About 3-4 euros a pop.