Trident Late budding and Screen side pots

[mcpesq817]

I tried screen sided pots for the air pruning effect. Vance Wood and others have touted the benefits so I thought it worth a try. Now I am not sure about tridents in these pots. My pines in these types of pots came through fine. Only tridents had a problem.

Frank

I've used pond baskets for pines and junipers to great effect - the root growth is fantastic. Because you don't repot them frequently, I think they can really benefit from the air pruning effects.

On the other hand, tridents seem to push out roots with ease, so much so that I find myself needing to repot them fairly often. Plus, they don't have the same drainage concerns as conifers, so I'm not sure that pond baskets are needed.

 

[Brian Van Fleet]

I overwinter my bonsai on the ground, but place them up on bricks --placed at either end of the pot suspending the pot over the soil. I THEN cover them with mulch.

This is exactly how I overwinter in B'ham and have never had a problem...even last winter when temps got down to 12-13F at night for a couple weeks at a time. My benches have a brick "floor" underneath them, and in December, they all go under the benches, then I rake pine straw from the yard and bury them up to the first branch or so.

 

[FrankP999]

I don't have that many bricks HA HA. I would have thought keeping mine on a screened in porch covered by blankets provided temp control. Plus I used a small light bulb for supplemental heat when temps dropped below 25. I think my problem was the extra drying in pond baskets.

Frank

 

[rockm]

"I don't have that many bricks HA HA."

I have well over 24 trees, some quite large (over 3 1/2 feet tall with correspondingly large pots --24 inches wide) I use bricks on all of them. The big ones require paving bricks. This only begs the question though, bricks are only one alternative.

 

[BoneSci]

Thanks rockm,

I'm in northeast PA where it gets quite cold at times. It can be down to single digits for days. I have been burying my trees in pots for years now, although the majority of then are in cut-down nursery pots or mica training pots. I don't have a cold-frame or hoop-house, but I have been considering making one to at least protect the azaleas in.

I typically bury the pots deep enough so that there is soil over the bonsai pot also - I know this is probably even worse, but maybe it prevents some water from making it into the pot. Maybe I've just been extremely lucky. It's just been easier for me than to try to watch the temps in a cold frame on those warmer days etc. Maybe I can put some mulch or leaves underneath the pots when I bury them to make sure they drain (sorta like the brick idea, but with teh added benefit of having them break down for my spring seed planting )

Thanks again,
Chris

 

[rockm]

I have a plastic tent cold frame over a foot deep cold pit here in Va--where warmer winter days require opening the frame up to vent it. I have it sited in shade to help prevent heat build up. I've found that six to eight inches down in the mulch temp remain remarkably constant--it can take more than few days above 50 to thaw even three inches down... We also get single digit temps here for days at a time in deep winter. I found that too much moisture in soil in the winter can produce die back on major branches-even trunks. I can better regulate the amount of moisture with in the cold frame with more cold sensitive species like trident.

I don't have to worry about watering the other trees that are mulched in the open on bricks. Since they drain very easily, rain and snow keep the mulch adequately moist from Nov. to March. I don't water them at all.

 

[FrankP999]

So what kind of training pots do you guys use on your tridents?

Thanks

Frank

 

[Dav4]

It depends. When I was growing out my tridents for trunk development, they were planted in the ground. From the ground, they would go into a nursery can or a wooden training box for a year or two. Finally they'd end up in a bonsai pot, but not the final one.

Dave

 

[mcpesq817]

Depends for me as well. I use the ground, or if in pots, plastic squat pots or other nursery type containers and mica pots. I also use Anderson flats, which seem to be incredible at developing great root systems (not only for tridents, but I had amazing results on other species like japanese maples and cork bark elms).

 

[Mojosan]

The short story is that all the moisture in the soil must freeze before the soil temp falls below 32F.

You do realize that this is an impossibility.......right?

 

[rockm]

"The short story is that all the moisture in the soil must freeze before the soil temp falls below 32F."

This is not completely true, but it's got the concept of how water freezes--freezing water disperses heat. Additionally, moist soil also holds more heat than dry soil, just as warm air can hold more moisture than cold.

This is a good article on how things work:
http://evergreengardenworks.com/overwint.htm

This is another thorough and informative one on overwintering, including the stages of root freezing:
http://evergreengardenworks.com/frzekill.htm

 

[Dav4]

You do realize that this is an impossibility.......right?

Thanks for your help, you really added to the discussion.....

Yes, I realize solutes in the soil moisture lower it's freezing point. I thought I'd keep things relatively straight forward and simple to understand, as everyone associates 32F as the temp where water freezes...Er, I mean distilled water..sorry for not being more clear. Sorry I so confused you Mojo. Anyway, Mark was nice enough to include the link to Brents' article which I mentioned; they are a great reference.

 

[Mojosan]

Dav4, hey - it just wasn't quite on target. Relax.

Rockm - you say that it is bad practice to bury pots for the winter because the ground does not have the same drainage capacity as the fast draining soil in the pot, thereby creating a 'swamp condition' for the roots. There might be other reasons why it is not a good idea, but this just does not seem reasonable to me. Trees planted directly in the ground would be exposed to the same moisture levels as the trees in the pots, no matter how the water got down to root depth.

 

[BoneSci]

Brent's article says the critical temp point in 15 degrees. If there is reliable snowfall that could be used to isulate the trees, they can be heeled into the ground and covered with a mulch halfwaay up the trunk. The cold frame seems to come into play when there is not a reliable snow covering (like where I am). I think this explains why I occasionally lose an apex - this is the area exposed to the extreme cold. Although this winter was 'rough' it seems to have worked to my advantage because my trees were covered with snow for the majority of the time.

There is no mention of things being to wet by these methods, just too dry if there is not enough precipitation (or when using the cold frame). I also question the root rot worry, because at these temperatures, I am not sure if the pathogens that cause this would be active. The spring would pose the greatest danger here at the soil temps warm up and if hte trees are left in too long. but htis is all just speculation here....

Thanks for the article links and the great discussion!
Chris

 

[Dav4]

Dav4, hey - it just wasn't quite on target. Relax.

Hey Mojo, my comments were spot on target, at least in the context of this discussion. Ok, for the nitpickers out there, I should have said that water in you soil will freeze "just below 32F", instead of "at 32F". I even referenced Brents' article which, for those interested, goes into much greater depth and detail on the subject then I was willing or able to. I honestly don't understand why you brought it up...

Dave

 

[Vance Wood]

The trees in the screen sided pots seem to have had some "issues" with overwintering. I'd suspect they dried out faster than their solid pot companions--Frozen soil can give up moisture even though it's frozen--especially in colder conditions. The screen may have allowed that to happen faster, as solid pots can shield evaporation somewhat.

Also, not to be a nag, but blankets and porches are a very poor overwintering media. Blankets don't retain moisture (moist roots are critical to overwintering trees as water in the soil protects roots) and provide no protection against cold. Plants have no internal heating mechanism--blankets cannot trap heat that isn't there to begin with...Pots on the porch are also not protected from the cold as a raised porch is exposed not only from the sides, but also from underneath. It's also subject to more temperature fluctuation.

Mulched plants on the ground against the house or in a protected area on the ground is more suitable. I've overwintered tridents here in No. Va. when temps ranged well into single digits and even below zero by mulching pots eight to nine inches deep in a cold pit a foot deep.That keeps temps evened out and the mulch retains moisture--I allow only snow and rain to water them.

I'd not give up hope on your trees. Keep them moist and in the shade until the end of June. See what happens. They may surprise you.

I suspect that the light bulbs may have warmed up the soil mass on the screen sided pots too much. In my experience with Tridents, which I do not grow any more, it is those in ceramic pots that suffer. I have found, or concluded wrongly, that the roots of Tridents are fussy. In ceramic pots if allowed to become root bound, the roots will turn to mush when exposed to freezing and thawing. I suspect that in the screened containers the addition of heat warmed them up enough so as to cause them to start to function out of season.

Either way and no matter the cause, because I doubt anyone can give you a better answer, that maybe you should not use a screened planter or pond basket for Tridents as long as treated in the way described. It is possible that the light bulb never allowed the trees to become dormant, and exposing what is essentially a bare root mass to an unnatural heat source may have caused the problem. This may be a classical example of killing your trees with kindness.

 

[FrankP999]

Vance
Thank you - I think your answer combined with more drying in the pond baskets accounts for my problems. I appreciate your thoughts. By the way, a JBP in one of your patented hand crafted screen side pots came through just fine - but I never brought it inside my porch.

Frank

 

[Vance Wood]

Vance
Thank you - I think your answer combined with more drying in the pond baskets accounts for my problems. I appreciate your thoughts. By the way, a JBP in one of your patented hand crafted screen side pots came through just fine - but I never brought it inside my porch.

Frank

I have only shared with you my thoughts and limited experience with Tridents. I no long bother with them, our winters are too cold and winter survival of potted specimens is iffy.

 

[rockm]

"Trees planted directly in the ground would be exposed to the same moisture levels as the trees in the pots, no matter how the water got down to root depth."

Simply not true and overlooks the obvious--the pot is the limiting factor here. Trees in the ground don't have their roots encased in a container with two drain holes that is itself encased in slower draining soil. All things being equal (unless you live somewhere like the Achafalaya swamp) the ground has infinite capacity to drain itself. The pot does not. Water will stand longer in the pot because the soil it in drains through bottlenecks--the drain holes. These bottleneck situation is complicated by the ground soil that's packed underneath the pot. It's like stuffing a clay plug into the drainage holes... It doesn't matter what the surrounding soil does (and ground water has infinite drainage capacity compared to a bonsai pot. It only matters that the soil in the bonsai pot can't get rid of water fast enough to prevent root damage.

Even landscapers recognize the danger of drainage problems when planting a tree. They advise making sure not to plant the tree too deep, include a raised central point and to poke holes through "glazing" caused by digging:
http://www.tree-planting.com/tree-planting-4.htm

I've seen people dig holes and store potted trees in them over winter. In spring they inevitably show the same kind of damage, sporadic dead branches and partial trunk die-back can be typical. Root rot and soggy soil are always present upon root inspection. Means there's been consistent water build up over the winter.

If you do want to store plants this way, GET THEM OUT OF THE POT and heel them into the ground. Without the pot, your argument is correct. You've eliminated the complicating factor in all of this--the container.