Let's All Get Some Answers and Not Wait for the Book

0soyoung

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I mean answers to horticultural bonsai questions and/or problems.

I didn’t really intend to hijack IntriguedByBonsai’s thread, but nonetheless I did. What set me off was Attila Soos’ rant that “…by and large, WE HAVE NO IDEA what to do with these wonderful trees [pinus contorta = lodgepole pine]. We don't even have a Mugo book, for goodness' sake. Neither [do] we have a Redwood, or a California Juniper book, which is beyond comprehension.” You can read all about it there; I won’t repeat it here.
What I had in mind was native American species and/or species we commonly find in home gardens. Japan has its native species bonsai and Europe has theirs. I know that I will offend some, but in America we basically have junipers. Otherwise, we seem to keep working with Japanese species (not that there is anything wrong with that). The only real change lately is Ryan Neil loves Ponderosas and Randy Knight finds the best yamadori. I know that other people have been doing serious stuff, but this is how the American bonsai scene impresses me in the short time I’ve been playing on its outskirts. But this is just background. I don’t mean to restrict BNuts in any way.

So, for me there are two basic issues to begin with:
  1. When can we repot (meaning with root pruning and hence dig yamadori) trees?
    • Spring, ‘as buds swell’ is known
    • August/September when growth stops??
  2. If I can’t treat it like a JBP, then how?

My thinking is that we collectively can find our own answers using cheap/junk trees. These might be nursery trees (even saplings) or ‘junk-adori’. The point is that each of us should accept the fact that we are probably going to kill a lot of trees in the process. Killing trees, of course, is not the goal. Learning something, answering our horticultural questions is the goal. But it will cost money in dead trees - hence the sole reason for experimenting with cheap junk.

Regarding 1. Repotting: Vance Wood has demonstrated that Mugo pines are best repotted in August/September. My bet is that most, if not all, conifers likely can be repotted this same time of year as well as a large number of deciduous trees. I know from home-gardening experience that woody perennials (like roses) can similarly be repotted at that time of year. Further my wife made me aware that, ‘everything just stops growing then – its like the plants all take a deep breath before starting their fall work of getting ready for winter’ (or words to that effect). I’ve been intrigued by the question of why does Vance’s revelation work, thinking that maybe it has a connection to the shift from early wood to late wood. I’ve yet to find anything in scholarly papers so far, but I keep encountering studies that talk about ‘growth cessation’ in August/September with pines/spruces growing around the Mediterranean (Israel, Spain), to as far north as Finland.

I am suggesting that we repot (meaning bare root and root prune) some conifers and deciduous (angiosperms) trees when they have ceased growing for the season (August/September). What species are of common interest?

Regarding 2. How to treat it: Is far more complex question (set), IMHO. Ryan Neil, has extensive university horticultural study in addition to his extended apprenticeship with Kimura. He starts with separating out single flush species from those like JBP that can produce multiple flushes in one season. This could be a suitable first group experiment if we don’t know or want to challenge conventional wisdom. I am boggled right now.

What do we want to work on: lodge pole pines (pinus contorta), junipers, and redwoods per Attila Soos? Hemlocks (Tsugas) and Douglas firs? Arborvitae (american/western/eastern ‘cedars’)? What are our common interests?

From here, I suppose it will make sense to form a group or groups for our collective projects rather than leaving bits and pieces laying all over the place for the coming season(s).
 
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I like this plan.

For myself, I'm finding that North American broad-leaf species such as certain maples and oaks are easily attainable, and in the conifer category, I can obtain junipers such as juniperus communis, Juniperus virginiana, Juniperus squamata (grown as an ornamental in the U.S.), juniperus chinensis (shimpaku), Juniperus procumbens, and Dawn Redwoods (clearly not a juniper). The hemlocks, firs, and cedars that would be easily attainable for me seem to be mostly Asian species that aren't really present in North America.

So here's what I think I'll do: I'll just go ahead and purchase a few specimens of various trees that are native to or common in North America. When I've purchased them, I can start posting information wherever we decide to post (different threads for different species and different experiments?) and if anyone else wants to focus on anything else in particular, I'll look at what you guys are experimenting on and see if I can find it somewhere here in China. I'm currently excited about the fact that I discovered Quercus rubra, Quercus palustris, and Acer rubrum here in China, so I think I'll start with those and maybe a couple junipers and Dawn Redwoods as well.

Thoughts, anyone?
 
I like your idea Oso, and no hard feelings about that thread. It makes a lot of sense though. Why don't we have a bonsai book on our own native trees? Why are our eyes only set on what originates in Japan or elsewhere? I might be taking a gamble with that lodgepole anyways. Considering where it came from, and our extreme summer heat. It may pose a threat to it's health, but who knows at this point, and only time will tell. I'll give it until spring of '14 before attempting anything drastic.
 
I'm a little confused by this post. Are you referring to evergreen conifers when you say (or imply) that we know little to nothing about native North American species for bonsai? If this is true, then you've missed the boat somewhere. We have broad and deep expertise in the U.S. in regard to most commonly grown native species, even though books have not been written about most of them. Native maples, elms, bald cypress, redwood, hornbeam, azaleas, crape myrtle, the list goes on and on. I think it's great that you plan to practice on lots of "junk" trees, and we should always strive to add to our knowledge, but the idea that no one has figured anything out in regard to our native material is just plain wrong.

If I didn't understand something in your post, apologies in advance.

Zach
 
If you're creating a list of native plants, there are several species of oak that should be on that list.

Also, our continent contains such diversity in climates and ecosystems that it is difficult to make broad sweeping statements that are true of all regions. Nonetheless, some information is better than no information.
 
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Please don't forget to write the chapter that fits into my growing area. I don't want to be surprised when all my plants die because I followed the advice of someone growing natives in New Hampshire.
 
Oso, I posted here in some other thread that I have found over the years that Aug/Sept is a good time to re-pot any juniper I have ever worked with. I have never had a hitch when bare rooting, root trimming and repotting one during that time. I have more problems in the spring with the chance of an unexpected freeze on a newly repotted plant. I have had many if not all American species of juniper and quite a few Japanese and Chinese varieties as well.

ed
 
Just join the American Bonsai Society and learn all about natives.
 
The potting time comparison is a good place to begin with statistical, horticultural testing. Think about measuring the heights of 10 year old wild oak trees, for example. I think you can appreciate that even though they may average 12 feet, some are going to be smaller and some will be taller. The actual heights of the shortest tree might be 8 feet and the tallest 15 feet, say (of course, the rest are also of differing heights between these two extremes). So, suppose you arbitrarily pick one of these wild oaks and compare its height to your 10 year old Japanese maple and find that the Japanese maple is taller. Can you now say that 10 year old Japanese maples are taller than 10 year old wild oaks? Of course not, but this is exactly what we often claim to be ‘proof’ of our bonsai techniques. So we need enough trees in each test group to estimate the variation within the group. To shorten this long story, we will each need 8 to 10 trees of each specie tested, half of which will be repotted in spring and the others that will be repotted in Aug/Sep for the experiment to yield statically meaningful conclusions about whether one time is better for repotting than the other, or not. This presents a bit of a cost/benefit dilemma that you will have to decide for yourself.

I have ordered seedlings of each Douglas fir (Pseudotsuga menziesii var. glauca) and Lodgepole pine (Pinus contorta var. latifolia). I wanted to get the coastal variety of Douglas fir, but ArborDay.org had a deal I couldn’t refuse. In exchange for a $10 membership fee, they knock the unit price down from $4 to $2.50 per tree and throw in 10 eastern redbud (Cercis Canadensis) seedlings. I am thinking about getting one more specie - cork oak or a prunus, maybe.

Experiments are designed to find measurable responses. While we can deal with some number of trees dying or living, the experiment will be much more powerful if there is something we can measure that has a value. I am thinking that we should measure the weight of the trees. Since trees fix carbon, healthy trees will get heavier than sickly trees.

So, when my seedlings arrive this spring, I plan to simply wash out the roots, blot them dry with a towel and weigh each one before potting it. I will assign each seedling 1) a unique i.d., 2) tag the tree with that id#, and 3) record its weight by id#. I am also planning to keep them grouped in a tray and will randomly assign them a position in the tray (write each i.d. number on a slip of paper and blindly draw a slip; first drawn goes in the first position, etc.). I will also rotate this tray one quarter turn each week trying to keep all sides of all seedlings equally exposed to sunlight. All trees will be given identical amounts of food and watered evenly, en masse. All this ceremony is simply trying to keep the growing conditions for all the trees as identical as I possibly can.

Come August/September 2013, when it appears that growth has ceased, I will randomly choose 5 of the 10 seedlings for repotting. I will first gently clean the soil from the roots, blot them dry, and record the weight of each by id# and the date. I will photograph the roots of each tree before and after I have combed and pruned the roots. Then I will again photograph the roots and record the root-pruned weight of each tree before replanting in its pot. The difference in the weight of the tree before root pruning and after, of course, measures the root mass removed. The other trees will be similarly repotted ‘with bud swell’ in the spring of 2014.

At this point (spring 2014) all trees were initially potted (without root pruning) spring 2013. The Aug/Sep repot group was potted only for the period spring to Aug/Sep (ca. 6 months) whereas the spring group has been potted for an entire year. So, I really should run the experiment one more season. Then in Aug/Sep 2014 I will have the measured year-long ‘Aug/Sep-to-Aug/Sep repot’ and in the spring of 2015 the year-long spring-to-spring repot effects which will be more of an apples-to-apples comparison.

Unfortunately, there is no getting around how long this will take. However, if anyone also using one of the species that Daygan or I are, will be ‘simultaneously’ (instead of serially) and blindly (without any ‘inside knowledge’ or prejudice) reproducing our experiments (just follow the same procedure). Likewise, for any other BNuts that choose the same specie will also be replicating one another’s experiment (possibly revealing whether climate is a strong influence or not). Contrast that with how things have been. Vance Wood says that he’s been working on Aug/Sep repotting of Mugo pines for more than 10 years. Some others have tried a tree or two (me included) and have had differing results – and that is about all we really know (you may disagree).
 
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I'm a little confused by this post. Are you referring to evergreen conifers when you say (or imply) that we know little to nothing about native North American species for bonsai? If this is true, then you've missed the boat somewhere. We have broad and deep expertise in the U.S. in regard to most commonly grown native species, even though books have not been written about most of them. Native maples, elms, bald cypress, redwood, hornbeam, azaleas, crape myrtle, the list goes on and on. I think it's great that you plan to practice on lots of "junk" trees, and we should always strive to add to our knowledge, but the idea that no one has figured anything out in regard to our native material is just plain wrong.

If I didn't understand something in your post, apologies in advance.

Zach

Sorry, I was just opining as a matter of background for this thread. I undoubtedly have missed the boat because I only involved myself with bonsai about 4 years ago. I've been reading everything I could find while playing at it and, in the last year, participating in BNut and a few other similar forums. Knowledge of native species is either highly coveted and screted away (Bogarted, on other words) or very obscure.

On the other hand, I am challenging what we 'know'. Do we know it as a matter of anecdotal experience or do we 'know' on a scientific basis with data. Like many others I am also guilty of waiting for someone to write a book or otherwise tell me how to do it, rather than experimenting to learn something for myself. There is no reason I/we cannot do as the experts did - experiment and learn how. That is what I'm going to do and I am thinking that a number of BNuts might find experiments I am proposing here to be fun and (maybe) enlightening.

Still confusing?

You aren't the first to have that complaint about me. I mean well, but simply cannot help myself. This marketing of ideas is tough.
 
Please don't forget to write the chapter that fits into my growing area. I don't want to be surprised when all my plants die because I followed the advice of someone growing natives in New Hampshire.

I am posing a group grope.

Data, not anecdotal tales.

The only book will be here in BNut and written by all who wish to participate. Participation is optional. Sneers and derision are options as well. :)

To each his own.
 
Oso, I posted here in some other thread that I have found over the years that Aug/Sept is a good time to re-pot any juniper I have ever worked with. I have never had a hitch when bare rooting, root trimming and repotting one during that time. I have more problems in the spring with the chance of an unexpected freeze on a newly repotted plant. I have had many if not all American species of juniper and quite a few Japanese and Chinese varieties as well.

ed

Thanks, Ed.
I too have uprooted junipers from my yard and potted them - one died, one is still with me. I've done many azaleas, but not with root pruning and replacement of soil as one might need to do with bonsai. It certainly indicates spring may not necessarily be the best time to repot, but at this point we've got little more than 'it works for me'. Maybe we can do better.
 
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...
So, when my seedlings arrive this spring, I plan to simply wash out the roots, blot them dry with a towel and weigh each one before potting it. I will assign each seedling 1) a unique i.d., 2) tag the tree with that id#, and...
...
...Then in Aug/Sep 2014 I will have the measured year-long ‘Aug/Sep-to-Aug/Sep repot’ and in the spring of 2015 the year-long spring-to-spring repot effects which will be more of an apples-to-apples comparison.

Now that's thorough!
 
Sorry, I was just opining as a matter of background for this thread. I undoubtedly have missed the boat because I only involved myself with bonsai about 4 years ago. I've been reading everything I could find while playing at it and, in the last year, participating in BNut and a few other similar forums. Knowledge of native species is either highly coveted and screted away (Bogarted, on other words) or very obscure.

On the other hand, I am challenging what we 'know'. Do we know it as a matter of anecdotal experience or do we 'know' on a scientific basis with data. Like many others I am also guilty of waiting for someone to write a book or otherwise tell me how to do it, rather than experimenting to learn something for myself. There is no reason I/we cannot do as the experts did - experiment and learn how. That is what I'm going to do and I am thinking that a number of BNuts might find experiments I am proposing here to be fun and (maybe) enlightening.

Still confusing?

You aren't the first to have that complaint about me. I mean well, but simply cannot help myself. This marketing of ideas is tough.
Don't take my post as complaining, I just hate to see anyone try to reinvent a wheel. Now, as to what we "know," your point is well taken. Under the best of circumstances, we know what we know from trial and error, but it must be clearly understood that there's less science in this than we'd like (in a past life I was in industrial research). Our experiments may be poorly designed, or we may misinterpret the results from a pretty well-designed experiment. So we have to be careful when drawing conclusions, and even more careful when trying to apply what we've learned across hardiness zones and even from one person's backyard micro-climate to another.

I hope this helps. Don't be discouraged, and please share whatever you may learn about the species you work with. No one, and I mean no one, knows it all.

Zach
 
On repotting times of year; my understanding has been that you generally want to do this just before or during an active growth period. This is why spring is so popular. Also I have read in several places that pines/conifers generally put much of their energy in to root production during the late summer/fall period...(August/September) I have found this to be true both in repotting and collecting... so I wouldn't say that it is necessarily a late summer dormancy (though I do believe heat stress can cause this) that is the primary reason for repotting this time of year, but a late season root push. -- I can't say this is the case with deciduous trees as I have always potted them in spring.

I'm not saying that dormant repotting doesn't work, I just think there may be other reasons for potting in August/September...(or relative time in your climate) -- the dormant seasons in my climate would be extremely harsh for potting, though I think it can be done if you are able to protect the plant from the extremes.

Just my experience and understanding. :) I'd love to hear others thoughts and experiences on this.
 
‘Reverse taper’, ‘no taper’, and similar esthetic defects are frequent problems that have shown up in bonsai forum discussions (I imagine that it is also in some old bonsai magazines/books too). I’ve read several threads claiming that pounding the trunk with a hammer works and, more recently, another claiming thickening by vertical cuts. I’ve decided to include ‘thickening by a thousand cuts’ as a factor in my experiments because it also is a way for me to learn whether the Aug/Sep growth cessation corresponds to the earlywood/latewood transition or not. Of course, I will have to sacrifice a few trees for cross-sectioning at some point to find out.
I will use a simple 2-level factorial design (I give it a name in case you want to read up) to do this. Each row in the table below is a group of trees. It is a common convention that each of these groups is referred to as experiment ‘run’ (an obvious influence of industrial manufacturing). This could be done with as few as 3 trees per run without sacrificing the resolution of the original potting experiment (a total stock of 12 trees).

[table="width: 500, class: grid, align: center"]
[tr]
[td]Factors -->[/td]
[td]repot[/td]
[td]1000 cuts[/td]
[/tr]
[tr]
[td]run 1[/td]
[td]spring[/td]
[td]no[/td]
[/tr]
[tr]
[td]run 2[/td]
[td]spring[/td]
[td]yes[/td]
[/tr]
[tr]
[td]run 3[/td]
[td]Aug/Sep[/td]
[td]no[/td]
[/tr]
[tr]
[td]run 4[/td]
[td]Aug/Sep[/td]
[td]yes[/td]
[/tr]
[/table]

Since I will be experimenting with young seedlings, I plan to make eight (8) vertical cuts (each something like one-half to one inch long) equally spaced around the circumference of the trunk when I am repotting the runs that get this treatment. Of course it would make sense to measure the caliper at each potting, but my measurement errors will almost certainly be much larger than the effect. So, it is likely that the response to this treatment will be just what can be seen in a photograph – a bulge or not in the trunk where the cuts were made.
As I said, at some point I will sacrifice some of the seedlings to cross-section their trunks. My thinking is that the damage to the xylem that existed at the time I made the cuts will remain, whereas the cambium will have healed after a short time and resumed producing xylem. Hence, it ought to be possible to determine where the repotting times are in terms of the earlywood/latewood growth pattern.

Maybe thickening by a thousand cuts doesn’t interest you, but something else does. Maybe something like comparing two different soils, or two different fertilizers interests you. Just substitute your factor of interest. It could even be something like full sun versus shade or two different places in your garden, or, I suppose, growing inside versus outside. You would simply grow the designated runs as a group in the specified locations. Further, it could be the extent of the root pruning at potting. The treatment could be as simple as root pruned versus not or a bit more subtle if you have some repeatable measure of heavy versus light root pruning, say.
 
I’ve been thinking about how to get more bang for the buck (time is also money) from the repotting experiment. It seems to me that developing ramification can be incorporated into the experimental design without introducing serious noise/errors that might hide the effects of Aug/Sep versus spring (bud swell) potting.

In my view there basically are only two things that I can do to a lodgepole pine, Douglas fir, or similar conifer to develop ramification:
1. Cut the new shoot, leaving 2 or 3 rows of needles (treat it like a JWP)
2. Remove the newly hardened shoot (treat it like a JBP)

For deciduous trees, including broadleaf evergreens (e.g., camellia and live oak) it’s only:
1. Defoliate
2. Or not

On second thought, there is more, even though it isn’t exactly ramification. With pines, spruces, firs and the like, there is a question of whether ‘back buds’ occur where needles exist or where they used to be. Similarly, there is the possibility of nipping off the tip of a deciduous or broad leafed evergreen shoot tip that could be seen as the analog to candle pruning. Nipping back the shoot during active growth (i.e., basically just removing the bud(s) at the tip) isn’t used much in bonsai, but an experiment is an experiment, so I might as well include it too.

I will only do heavier pruning (if at all), like ‘chasing back the foliage’, as part of repotting so that the weight loss will not affect the measurement of each tree’s annual weight gain. Similarly, extensive defoliation could easily have a major impact on a tree’s annual weight gain (loss), especially with saplings. So I will only defoliate sparingly; like removing needles from one side of last year’s node on one branch and one side of two years-ago’s node on another - otherwise leaving all the rest of the foliage be. I keep having to remind myself that my objectives are to see the effects on ramification and back budding. Later, I can always find out how hard things can be pushed.

To sum up what I am planning to do is:

[table="width: 500, class: grid, align: center"]
[tr]
[td]Factor -->[/td]
[td]repot[/td]
[td]1000 cuts[/td]
[td]shoot prune[/td]
[td]defoliate[/td]
[/tr]
[tr]
[td]run 1[/td]
[td]spring[/td]
[td]no[/td]
[td]
-​
[/td]
[td]
+​
[/td]
[/tr]
[tr]
[td]run 2[/td]
[td]spring[/td]
[td]no[/td]
[td]
+​
[/td]
[td]
-​
[/td]
[/tr]
[tr]
[td]run 3[/td]
[td]spring[/td]
[td]yes[/td]
[td]
-​
[/td]
[td]
-​
[/td]
[/tr]
[tr]
[td]run 4[/td]
[td]spring[/td]
[td]yes[/td]
[td]
+​
[/td]
[td]
+​
[/td]
[/tr]
[tr]
[td]run 5[/td]
[td]Aug/Sep[/td]
[td]no[/td]
[td]
-​
[/td]
[td]
+​
[/td]
[/tr]
[tr]
[td]run 6[/td]
[td]Aug/Sep[/td]
[td]no[/td]
[td]
+​
[/td]
[td]
-​
[/td]
[/tr]
[tr]
[td]run 7[/td]
[td]Aug/Sep[/td]
[td]yes[/td]
[td]
-​
[/td]
[td]
-​
[/td]
[/tr]
[tr]
[td]run 8[/td]
[td]Aug/Sep[/td]
[td]yes[/td]
[td]
+​
[/td]
[td]
+​
[/td]
[/tr]
[/table]

• Douglas fir & Lodge pole pine: 16 plants each (2 per run)
o Shoot prune ‘+’ = cut candle keeping some of the new needles (treat like a JWP)
o Shoot prune ‘-‘ = remove the entire newly hardened candle (treat like a JBP)
o Defoliate ‘+’ = remove needles one side of branch segment
o Defoliate ‘-‘ = do nothing
• Red bud & cork Oak: 8 plants each (1 per run)
o Shoot prune ‘+’ = nip shoot tip to just remove terminal leaves
o Shoot prune ‘-‘ = do nothing
o Defoliate ‘+’ = remove fraction of leaves by cutting through petiole
o Defoliate ‘-‘ = do nothing​
 
In my original repotting experiment proposal I suggested that one needs to have a total of 8 or 10 trees – 4 (or 5) repotted in spring and another 4 (or 5) repotted in Aug/Sep. My purpose in this post is to provide a little background for this.

First, I am hoping to not kill anything. I am going to the trouble of weighing every tree when it is repotted so that I can keep track of the seasonal weight gain, thinking that this is a good measure of tree health. I don’t know, however, that the weights will necessarily be normally distributed as is required by the established statistical analysis methods. The Central Limit Theorem, however, tells us that if we use groups of n trees, the average weight of these groups will be approximately normal. The convergence is at least as fast as 1 over the square root of n. For all practical intents, the average is normally distributed if we use groups of at least 4 or 5 trees.


On the other hand, suppose a few trees die. The question we should ask ourselves is whether we could have gotten the same results just by dumb luck. That is, maybe the trees really died for some reason that was present in the beginning and they just got assigned to that experiment group by nothing more than the luck-of-the-draw. To see the results that simple random chance would produce we presume that all of our trees were in a ‘big bucket’ and that we randomly drew trees, arbitrarily assigning each to one of our two groups; then repeat many times. While we could write a macro in a spreadsheet program to discover the probabilities, it is well known that they are given by the Hypergeometric distribution [in Excel =HYPGEOMDIST(k, n, K, N), where K is the number of dead trees observed in the N (= 2n) trees, n of which we have repotted in spring and the other n in Aug/Sep.]

We should not conclude that repotting had an effect unless the results we get are very unlikely to have been just random chance. Intuitively it is obvious that if we only had two trees (total) and one died, it could have equally well been randomly assigned to either spring repotting or Aug/Sep. Hence, we really cannot be confident that spring repotting is bad when we find the one tree repotted in spring died and the Aug/Sep repotted one lived. In fact, we really cannot say much of anything based on the results of one event versus another single event (contrary to claims I often read on this and other forums).

If we have more trees, say 4, in each repotting group, the chances of randomly having 0 (zero/no) dead trees in one group of 4 and 4 dead trees in the other is only about 1.4%. If 4 dead trees in one group were our result we can indeed conclude that it was due to fall repotting, say, because it is so unlikely to have occurred by dumb luck. If we only had 3 of the 4 spring repotted trees die, instead, we could still be confident that it was due to the repotting because this result has less than a 10% chance of being due to random chance.

The more trees per experiment group, the better the experiment will resolve the effect. Four per group, which is the case for in my red bud and cork Oak experiments, is minimal. With 8 trees per group, as I have in my Douglas fir and Lodgepole pine experiments, a potting effect can be discovered if as few as 3 trees should die in one repotting group or the other. My choice to use factorial experiment designs locks me into these two choices. As a simple paired comparison, instead, one is free to choose 4, 5, 6, 7, or any larger number of trees per group to balance the material costs against resolution of the experiment.

And there you have it. Probably a lot more than you wanted to know and likely every bit as tedious as your worst fears. Sleep well.;)
 
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