Double Colanders?

[QuintinBonsai]

I know that the purpose of the colander is to provide aeration to the roots, and allow good drainage. So what is the purpose of placing that colander into another larger colander?

 

[FrankP999]

the theory is that double colanders allow the roots to continue to grow when they have filled the first colander.

 

[cmeg1]

I could barely find any 6" colanders so I am now planting directly into 8" colanders with that method.I did have some 6" colanders and the root branching was quite spectacular with a seedling pine even after one growing season as I drooped one and sacrificed it to see the root growth.I feel confident that 8" or 9" colanders by themselves will do a fine job of making dense feeder roots with branching also.I am even throwing deciduous trees in large 13" colanders now.

 

[milehigh_7]

As the point of screen pots / pond baskets / strainers etc is "air pruning" the roots. I don't get the point of the double stack. What you want is for the roots to hit the edge, have the tips die from touching the air and have the long roots "back bud" in to smaller feeder roots.

If you keep em in more soil with too large of a container or a double stack you are defeating this purpose IMHO.

 

[Poink88]

As the point of screen pots / pond baskets / strainers etc is "air pruning" the roots. I don't get the point of the double stack. What you want is for the roots to hit the edge, have the tips die from touching the air and have the long roots "back bud" in to smaller feeder roots.

If you keep em in more soil with too large of a container or a double stack you are defeating this purpose IMHO.

I agree...not to mention how in the hell you will remove the inner collander later w/o obliterating all the roots outside it???

If you need to up pot...remove the (smaller) collander first before putting the tree in a bigger one. JMHO

 

[Dav4]

My understanding of the double colander method is that it allows for greater root growth (into the soil in the larger colander) followed by pruning without disturbing the root ball in the smaller colander. You pull the small colander out of the big collander, prune the roots back to the smaller colander, then place back into the big colander for more root growth. You still get the nebari developing benefit of the colander, but you get continued strong top growth because the majority of the rootball doesn't get disturbed.

 

[Eric Schrader]

Personally, after having grown pines using the double method and also having removed the smaller collander (without doing root work) before putting into the larger one, I prefer removal of the smaller one.

I think the original intent of the BT article was that there would be no disturbance to the roots while potting up, thus increasing the speed of trunk growth. The reality is that at least in my case after 5-6 years in the smaller collanders the nebari are nearly reaching the outer edges of the smaller collanders which makes it worrisome to cut back that far all in one go to get them out of the smaller containers. I'd prefer to be able to remove just the bottom half of the rootball without disturbing as much of the area surrounding the nebari...


I will say - I've gotten some really fantasitically branches root systems from these containers.

 

[QuintinBonsai]

As the point of screen pots / pond baskets / strainers etc is "air pruning" the roots. I don't get the point of the double stack. What you want is for the roots to hit the edge, have the tips die from touching the air and have the long roots "back bud" in to smaller feeder roots.

If you keep em in more soil with too large of a container or a double stack you are defeating this purpose IMHO.

That's what I was thinking. The Stone Lantern BT book doesn't give any explanation on doubling the colander. The only other thing I see is maybe to retain moisture? I've bought a couple of 1 gallon JBPs with the intent of growing them in colanders with fertilizer cakes as I've read. How do you guys manage keeping a colander from drying out?

 

[pwk5017]

I also grow in pine baskets and colanders and never bothered with stacking them. Always seemed like it would be an enormous pain to separate the roots from the inner colander/basket after a few years. I just pot up into the larger container with minimal to no root pruning. These things produce awesome root systems!

 

[AboveBeyond]

That's what I was thinking. The Stone Lantern BT book doesn't give any explanation on doubling the colander. The only other thing I see is maybe to retain moisture? I've bought a couple of 1 gallon JBPs with the intent of growing them in colanders with fertilizer cakes as I've read. How do you guys manage keeping a colander from drying out?

I have the same question. I just repotted one of my trees into a pond basket and it's drying out before the end of the day. Perhaps I should use a soil mixture that contains more fine bark to retain more moisture?

 

[lackhand]

This thread is the first I've heard of using doubled colanders, but I have heard of putting a colander in the ground. Seems like the same effect, but less worry about drying out. The point of the colander in this case would be that it's easy to lift the tree every year or so and prune the roots back to the edge of the colander. Gives you the benefits of ground growing, but helps develop the fine roots a bonsai needs at the same time. I'm trying this method out, but so far the colanders have been in the ground for about . . . 2 day. I'll get back to you next year.

 

[milehigh_7]

I grow nearly everything in strainers etc. During the summer when it is 120F I water up to 4x per day. More frequent is better anyhow. You get more oxygen to the roots this way. Again, the main reason to grow this way is air pruning the roots.

 

[milehigh_7]

First of all, credit where it is due. Our own Vance Wood owns a patent for screen sided pots so he may chime in with true expertise.

That said, here is a video that shows the air pruning I am talking about.

[video=youtube_share;wHhZeeTrfs0]http://youtu.be/wHhZeeTrfs0[/video]

 

[pwk5017]

Yes, the whole point of a mesh/colander/pond basket planter is for it to dry out as quickly as possible!!! It allows you to force feed the root system with water, nutrients, and air. This is why incredible growth is possible when proper care is taken. You should be watering twice a day(sometimes more as has been mentioned) if you are growing in 100% inorganic medium and one of these containers.

 

[nathanbs]

Pwk is right the main or original reason for growing in the colanders was to enable "superfeeding" to maximize the growth potential out of JBP specifically. Flush as much water and fertilizer through the tree as possible. Air pruning was not a reason for collander growing and that is why the second collander is added to prevent roots from drying out as they reached the edge of the collander. The point was to build the trunk quickly it wasnt necessarily about promoting fine roots.

 

[AboveBeyond]

Yes, the whole point of a mesh/colander/pond basket planter is for it to dry out as quickly as possible!!! It allows you to force feed the root system with water, nutrients, and air. This is why incredible growth is possible when proper care is taken. You should be watering twice a day(sometimes more as has been mentioned) if you are growing in 100% inorganic medium and one of these containers.

Makes sense, thanks!

 

[Ross]

I posted a thread about my experience with this a couple years ago.

http://bonsainut.com/forums/showthread.php?3824-colander-inside-a-colander

I got pretty good root growth on a Catlin elm in less than two months. The double colander allowed me to pull the little colander out to trim the roots. I never had to worry about drainage or circling roots, but it was tough to get the elm out of the little colander eventually because the roots grew through the holes and it had to be basically cut out. The lava rocks on the surface of the pot were supposed to discourage squirrels from burying their nuts in there.