The less damage to the roots the better. If there are circling roots, try to pull them apart and straighten out. If they are long, you should provide a much wider, not deeper, planting hole. "Vitamin B1" does not affect the plant when added as a supplement. The plant produces enough of its own. (University of California, Davis research).

For a page with links to pages discussing both topics...

Here is a link that might be useful: Horticultural Myths

Interesting reference ,bboy. Here are two more on the topics, that are actually some of the original research that is used in the Washington State summaries you mentioned.
http://anrcatalog.ucdavis.edu/pdf/8046.pdf
http://ohric.ucdavis.edu/Newsltr/fn_report/FNReportSp82.pdf

I first read about planting methods research in 'Organic Gardening', they had a sort of interview with Carl E. Whitcomb.

Here is a link that might be useful: Lacebark Inc.

So in even the above responses, we have conflicting information. One source says untangle the roots and remove as much container material as possible(but good used as a top dressing). Another source says root pruning to correct fatal root flaws when transplanting. When I did additional searching on root pruning, all the sources I found said to only do it at *least* a year before you know the tree will be transplanted.

So now I'm more confused than ever.

Untangle roots? Prune roots? How do you prune roots?

So I tried planting one of them by loosening up and untangling the rootball. There was definitely some broken roots.

There are several different types too. Some are woodier and seem to provide the tree support while others are white and almost like a thin styrofoam that break apart easily.

BTW, the holes were all dug with a 30" auger 3 feet deep and backfilled with the loose soil to a couple inches shorter than the rootball. Each one needs to be adjusted because not all the root balls are the same height in the pot. Sometimes some soil has to be scooped out and sometimes more put back in when settling the rootball on the bottom.

You're confusing pruning the roots at planting with pruning them in advance. All you need to know is you don't want to plant your trees with deformed roots like a dense plug at the bottom of their trunks. Do what you have to to correct this defect. If some of them also have burned tops those should probably be taken back. Figure on extra attention toward watering etc. after having mauled the roots.

I also favor washing the roots and trying to pull them open over arbitrarily slicing through them and cutting a bunch of root tissue away like the tree has an unlimited capacity for tolerating it. But what I end up doing with each specimen depends on the combination of factors that present themselves at the time, what looks like it will work in that instance.

in my sand.. i move/transplant most of my trees/conifers BARE ROOT ...

you are spending way to much effort on worrying about the root ball ... just do it ...

thicker roots that circle ... can.. might ... eventually ... some decades down the line circle the trunk and choke off the tree... a suicidal tree for lack of a better term.. lol ... those roots should be either straightened... or simple cut at the first circling bend ... just do it ... new feeder roots will develop at the cut.. dont worry about it ... just do it ...

the white brittle roots are probably .. if not weeds ... the feeder roots ... easily regenerated if you properly care for the trees this year and next ...

you dont mention your soil type ... in sand.. i am of the opinion.. that the trees roots will take off in any and every direction ... and most of what you are worrying about is moot ... just do it ...

in clay .. it may be a concern that the auger is shining up the augered edge.. and basically making a ceramic pot.. which the tree may never grow out of .. the roots just circling forever.. waiting for that one big wind storm ... more info as to soil type may help ...

you made the right decision to go with smaller stock ... so pat yourself on your back.. and never regret that decision ...

send me the money you will spend on B1 or any other amendments.... it will do just as much good in my pocket.. as it will for your trees .... lol

spend the money on mulch and water.. for the next two years ... ask if you need info on how to properly water them ...

working on this volume.. EXPECT to lose a few.... and dont bother blaming yourself if you do ... its just the odds ... follow up care is 10 times more important than worrying about the root issues ...

if you have your planting timing perfect .... you dont mention zone ... then JUST GET THEM IN .... and take care of them properly ... JUST DO IT ...

good luck

ken

PS: below is a picture of how i move trees on my lot ... ALL ROOTS ARE SEVERED .... so .... perhaps you are worrying a bit much ... i have never lost one.. due to proper followup care ... and sand ... THEME: JUST DO IT ... cut what needs to be cut.. and then go have a beer and dont worry about it ...
{{gwi:331094}}

You run some risk when you dig a planting hole deeper than the rootball intended for it. Settling of the loosened soil is the primary issue, resulting in the rootball sinking to an unfavorably low depth - this can be the kiss of death to many woody plants. If you have dug the hole deeper, water the loosened soil well and allow it to settle several days before planting.

For future planting activities, dig a planting hole with sloped or dished sides 2-3 times as wide as the rootball but no deeper. You can even dig it slightly shallower than the depth of the rootball and this is recommended if your soil is heavy clay or drains poorly. Backfill the planting hole only with the soil removed - you can use any amendments to topdress or mulch to the top of the rootball.

And B1 or transplant fertilizer is pretty much a waste of money. If soil tests determine it is necessary, apply an appropriate fertilizer formulation according to test results. Most woody plants do not require much in the way of fertilizers.

Wow! OK, that gives me some confidence.

The soil type varies between sandy loam, clay loam, and some clay. The last takes the longest to drain. And yes the auger was shining up the edges of the hole, but on every hole, I dug extra deep and then shaved more off the sides at an angle to loosen up the walls and to back fill.

So basically a couple of slits vertically to cut all the outer banding roots, and then some manual loosening should be no problem.

As far as watering, I have a drip line setup, 600 feet of it. I have to use PC drippers as the pressure drop over that length is too great to use the non compensating type.

I figured in the sandy loam, I'd water a great deal more than the the clay. I still don't know how much to water them. What I do know is that I'm setting up the drip for each hole first and then testing it to see how well it drains. I figured I don't want any standing water at all.

Sharply pruned roots will result in a flush of new roots just behind the cuts, something that can be quite beneficial for a newly planted container plant. Use a tool that will CUT the roots, not mash or rip them.

Something like a segmented exacto knife? How many cuts should I make? How deep?

The main thing is to get circling and kinked roots opened up. If there is an undiscovered deformity inside the center of the rootball that may produce difficulties years later. Badly knotted, fist-like roots discovered at the base of the stem dating from when a tree was left too long in a small band or pot may be unable to be repaired, making long-term success of the tree suspect. This is a common condition, unfortunately. I have had decades-old foundation shrubs fall over in the snow, to be found to have pivoted over on turnip-like knotted roots at the bases of their trunks.

sorka wrote: "some of the large trees had split their pots open. ...rootballs on all the trees were pretty tightly packed and spiral tightly circled."
Sorka, this looks to me like a substantial purchase. Can we assume that you didn't see the roots until you got home? If that's the case, that was your first mistake. In the future, have a few of the pots removed before purchase and check them out. It's kinda like smelling a fish before you buy it.
I'm assuming that the West Coast is just like where I live as far as a glut of nursery stock. By your description, your redwoods had been held over for one or two years in the same pots. I'd say they were fit for the compost pile.
Just out of curiosity, did you pay full price for them? There's no way that the consumer should be expected to take apart, unwind, bareroot, etc 48, 15 gallon trees. I've never dealt with Costco, do they offer a warranty? It's one thing to slit the roots on a batch of Blue Rug junipers, we used to do it all the time, but you're dealing with more substantial plants. I have a feeling that you paid top dollar but got bargain basement quality, is that right?

Yes: quite a chore. Most of the plants CostCo offers are OK when they come in but are displayed indoors, in a heated environment. And they are not set up for watering them.

Part of the benefit of membership is you can take things back.

The trees I bought never saw the inside of the store. They had just arrived. I did not buy the large 12 foot trees that were splitting out of their pots. I bought the 7 foot trees which were even smaller than the soquels that both Home Depot and Lowes had in 15 gallon pots. So I don't think these were kept in too long, but they do have circling roots.

The trees were $29.95 each. Is that top dollar? I don't know, but they were $8 more than Lowes and Home depot's 5 gallon container coast redwoods.

I'm still not clear on how I should prep the rootballs. Prune? Slit? Slit and loosen and how much?

You have gotten a lot of advice here, some of which may seem a bit contradictory, so I am not surprized that you don't have a clear idea of what to do.

First, let me say that as I have read this thread I have not jumped in because what I have seen here has generally been good advice. But I see now that you need a referee or something, so I will try to help.

One of the problems is that all trees are a little different. Not only is the degree of root "congestion" in the pot different, but different kinds of trees respond differently to different treatments. But I can't see--and feel, etc.--the roots you are dealing with, and I am not familiar with all the different species of trees and how they may react to different treatments. But let me give some general advice that will help you.

First, if you do any of the things recommended, it will be either good or OK. Slitting the rootball in thirds will keep any of the encircling roots from strangling some of the roots later. But undergropund roots generally don't strangle the tree--roots generally graft over themselves. The real danger is a root that encircles the base of the trunk (girdling root). These must be removed.

But better than slitting the root ball is as much as possible to "tease out" some of the encircling roots so they can be extended a bit. But often the root ball is so tight with the roots crossing each other, both in and then outside, that this is virtually impossible. In this case slitting the ball in three places is about all you can do.

If you can tease out/unwind some of the roots (and you can both do this and cut some larger/longer encircling roots) you will need a big hole to allow them to spread out a bit. But some of the roots you are able to tease out/unwind may be very, very long. In that case it may be beST to shorten them a bit, or a lot, because if you don't, they will still encircle the root system or make a tangle. But if that happens, it is not really fatal.

Sometimes with some kinds of trees in pots the root ball just seems like a dense fibrous mass. It is hard to find individual roots to tease out/unwind. In that case three slits and then some roughing up of the root mass to loosen it a bit is about all you can do.

If you do any of the things recommended here, you will be doing more than most people do when they plant these root bound trees. Have confidence and go ahead and do the best you can--use your common sense. A lot of this will be intuitive as you start working with these root balls. Just see what you can do to undo some of the tangle, one way or the other.

But one warning--these root bound trees will need more watering for maybe up to three years than a tree not so root bound. The roots will need time to get into the native soil--water that gets to the root mass that was originally in the pot will not last more than a day or two in hot weather. The more roots you can unwind/tease out and get into the native soil, the more drought resistance the tree will have.

--Spruce

Sorry for al the mistakes/typos in my previous post. I mistakenly hit "submit" instead or "preview" after making corrections. But my drift comes through anyway, I hope.

--Spruce

Wouldn't it be nice if everybody had used Whitcomb system (or something similar)???

Rootbound stock is so prevalent here that I have kind of given up on expecting to find a high percentage of acceptable purchases when shopping. Grafted collector conifers for instance are almost invariably found trapped on corkscrew-rooted understocks, production of camellias sold here is dominated by two large California growers that send these up with terrible roots also. At least with the latter one could buy an example of their garbage, comparatively easily root new ones from cuttings and then discard the original sad specimen.

Then there's all the grafted roses...

Lack of timely and efffective fertilization (if any is done at all) in local retail outlets is another recurring issue that cuts a wide swath through the quality of what is offered - it does not take long for frequently watered plant received growing in soilless potting media to become nutrient deficient.

Those roots keep growing after the retailer gets the plant as well. A large segment of the consuming public needs to react to the low standards being maintained in such a way that vendors see what is happening and decide it is cutting into their action before much improvement is likely.

I understand that you paid $29.95 for conifers in 15 gal containers.
Last week I attended an open house for one of the large, wholesale growers nearby. Their price for Leyland Cypress is $29.95 but they are in 7 gals and this is directly from the grower, no middlemen.
Our local wholesale yard charges $125-$135 for 15 gal conifers depending on species, no quantity break.
I just wish everyone could understand that every wholesale grower has a commercial shredder somewhere on the property. Overgrown, damaged, topheavy, unsalable material is run through the shredder. Right now there is a real glut. Sometimes the substandard stock makes it to the retailer and is sold for dirt cheap, it looks like that's what happened here.

I thought it was a good article. Click on the link...

Here is a link that might be useful: Click me

you know.. the more you learn .. the less you know ...

in bullet form ...

JUST DO IT ..... lol

second.. get a good pair of pruning shears.. like felcos ... any new pair .. and CLEANLY SNIP ROOTS ... razor blade to cut off pot.. but properly snipped roots ..

third ... water well at planting ...

proper mulch ...

DO NOT WATER AGAIN UNTIL THE ROOT BALL IS DRYING OR WARMING ... insert finger thru mulch to second knuckle ... when the soil is dry or warm ... water until it is damp at the rootball ... you may need to use a hand shovel and dig down.. to learn how water moves through your soil ....since you have multiple soil types ... you have to learn across all 3 ... WE CAN NOT TELL YOU when to water ...

if you put 50 gals of water on clay ... you will get a 100 foot circle of .01 inch of water.. and none at the roots ...

if you put 50 gals on sand... you will get a 5 foot wide funnel to 20 feet deep .. the difference being how the water moves thru the soil ...

plant.. water... walk away.. when you decide to water again .. run your drippers for an hour .. go dig small hole... see how deep it got... turn water back on for 6 more hours.. go check again ... etc ...

but.. JUST DO IT ...forget about worrying about it ... you will learn more by sticking the shovel in the ground. than by spending too many more hours reading ...

ken

The soil types vary enough and I'm paranoid about standing water in the areas that are clay. So before backfilling, I'm inserting a 2" perforated drain pipe vertically so that I can stick a dip stick in each one and check for standing water. I figure this will help me adjust the watering amount for drippers at each location.

Thanks for the advice everyone. The main thing that I've gotten from this is that touching the rootball is not going to hurt it and that proper watering is critical especially on trees that have had to have more severe corrective measures.

I found this thread very useful and informative.

Thanks to all who contributed.

you said:

The main thing that I've gotten from this is that touching the rootball is not going to hurt it and that proper watering is critical especially on trees that have had to have more severe corrective measures.

YOU GOT IT BUDDY .... JUST DO IT ...

think of it this way .. left in the pots.. they will all die ... and ANYTHING you do to get them out of the pots .. will be better than nothing ....

never heard of the pie idea... but who knows.. let us know how the experiment works ... this is how gardeners discover new things ...

if its too wet 2 foot down.. but ok in the first 2 feet.. guess where the trees will grow roots ... in the first two feet ... never forget... properly planted ... they are extremely able to care for themselves ... just dont screw it up... over thinking it all ...or in other words... DONT KILL THEM WITH TOO MUCH LOVE ....

KEN