Pine & Juniper re potting advice

[Snipz]

Hi all,

Now that my deciduous have been moved from nursery stock into a bonsai mix 1:1:1 I'm starting to research the next trees which to under go re-potting which I understand to be my coniferous.

Again, most of these are in nursery stock and I'd like to get them into a good free draining mix but understand there are some intricacies in regards re-potting due to stress and mycorrhiza etc

I've read that this can be done in one go or split over two Years leaving half the root ball in nursery stock whilst the other in the new mix (never bare root/wash the root ball)

Can anyone offer advice based on their experience as my preference would be to move entirely to 1:1:1 as quickly as possible so all my trees are in the same medium and re-potting regime.

I understand also that re-potting should be done in isolation i.e don't prune/style at the same time but open to any experience based advice here as again I'd like to set my trees up on the right foot for the growing season.

Thanks in anticipation
Snipz/Rick

[shibui]

A lot depends on the age of the tree. I can certainly bare root seedlings and cuttings of conifers any time of year without any ill effects on those trees but older trees need a little more care.
I still bare root (but don't wash) pines and junipers up to 10 years old and that does not seem to worry them. I generally remove some excess branches when reducing roots at repotting. When I dig pines and junipers from the grow beds I certainly reduce the root mass quite considerably and take off 1/3 -1/2 of the top at the same time. Those trees are then potted and placed on the nursery benches in full sun but they do get water as often as needed - most days.
It becomes impractical to really bare root older trees as the inner roots can be really matted and often merged together into a single lump of wood. In that case I just replace the outer mix and leave the inner rootball to look after itself.
I have not found it necessary to transfer mychorriza or even worry about it when repotting. Trees that are fed regularly don't really need it to convert nutrients for them but some will always be included in the remnants of soil on the roots and very quickly recolonises the new mix and roots if conditions suit. If conditions don't suit the mychorriza no amount of transferring or inoculating will get it established. the less you worry about it the quicker and stronger it seems to grow.

If your trees are young and healthy I think it will be OK to shake/rake out most of the older mix and get them straight into better mix.

[Raging Bull]

Hi Snipz,
I've dug pines (radiata) growing wild out at Coomera where a lot of new housing is going in and the soil is very poor. After digging, most of the soil came off the roots on the way home so I carefully pruned the tap root and potted the yamadori trees. They ranged in size from small seedling 30 cm high to small trees up to almost a metre high. They all had very strong tap roots and very few other small roots. The tap roots grew far too deep to dig out, the ground was like concrete, so I cut them off with the spade at about 20 cm. All of those pines are now doing well.
I've also root pruned a juniper purchased as a starter bonsai in February. I took it out of the plastic grow bag, raked and shook the roots out and trimmed about 30% off the bottom. After potting it, it didn't miss a beat and as soon as I saw that it was still strong and vigorous I started to thin it out and style it.
So as shibui says, go ahead and do the needed work, there should not be any problems. If you're still unsure, bring it to the G.C & Tweed Bonsai Club meeting next Saturday 10th of August, there are always plenty of helpful people there.
Cheers, Frank.

[Snipz]

Fantastic Neil/Frank, thank you for your advice!

Frank,

I live in Pimpama/Coomera and would love to get my hands on some Yamadori; would you mind if I PM'd you for some guidance?

Thanks
rick

[one_bonsai]

Fascinating. People often say don't bare root Junipers, only half bare root them.

[shibui]

Fascinating. People often say don't bare root Junipers, only half bare root them.

As I mentioned, a lot depends on the age and strength of the tree. Broad brush statements like 'don't bare root junipers' can be misleading without all the caveats and exceptions. There is also the matter of interpretation. What one person sees as 'bare root' may only be a light trim of the roots to another grower. Different climates may also require different techniques. In milder climates, like here, I think we can get away with far more than someone in a really harsh winter climate like Northern US or Canada. North QLD growers use some different times and techniques from us southerners because of their seasonal differences.

[Snipz]

I've watched Ryan's Black Pine workshop and think I've confused myself further now...

Pines - Strength in the roots
Spring or acquisition (check/check)
Balance the energy by plucking needles to 10-12 across the tree

OR

Re-pot into a good mix to improve the roots

What should I do first?

Junipers strength in the foliage

The junipers I have are over 10yrs old so probably wiser to re-pot into good mix and leave the foliage until next Year but wire for maximum sun/air at this time

Confused dot com

[shibui]

In my view balancing pine strength is only necessary when the trees reach the size and thickness you are happy with. Younger pines grow better and faster when they are allowed to grow freely. Free growth does need to be balanced with occasional cutback to keep some growing points where you can use them to develop the tree after growing phase is finished. That's a lot harder to properly describe in a few sentences.
Stage 1 - growing: allow shoots to grow freely for a year or 2 then cut back to the lowest healthy needles to get new buds growing. Repeat for as many cycles as required to get the trunk thickness required.
Stage 2 - ramification/ refinement: Now is the time to start needle plucking and decandling to get plenty of new short shoots along the branches and to balance strength so lower branches and interior shoots are just as vigorous as the apex and outer shoots. Branches and apex are allowed to extend slowly to the desired outline.
Stage 3 - maintenance: Each year the branches and apex grow longer as new terminal shoots extend. Continue with needle plucking and decandling to maintain short shoots, good shoot density and equal strength. Remove the ends of over long branches to maintain the desired outline.

I've heard Ryan's strength in roots strength in foliage catchcry for a few years now but still don't understand botanically what it means other than if you cut too many branches off a juniper it may die but if you cut too many roots off a juniper it will still die and if you cut too many branches off a pine they tend to die too

With young pines I have no problems root pruning and transplanting and I have cut back the top and roots when removing them from the grow beds and still get pretty good survival rates. Maybe this is more to do with older trees or those collected from the wild in US.

[wrcmad]

I've heard Ryan's strength in roots strength in foliage catchcry for a few years now but still don't understand botanically what it means other than if you cut too many branches off a juniper it may die but if you cut too many roots off a juniper it will still die and if you cut too many branches off a pine they tend to die too

My interpretation:

If you cut hard on a juniper's roots, you need to maintain the foliage to provide the energy to rejuvenate the roots. Cut foliage and roots at the same time at your peril.

If you candle prune and needle pluck a pine (easily up to 60% of the foliage removed, maybe more) then you need the stored energy in the roots to rejuvenate the foliage (Cut foliage and roots at the same time at your peril.)

[Snipz]

Thanks fellas; I'll just get them into a good mix and let them grow in a wooden grow box for a Year or two.

Off to procure some patience

[shibui]

Cut foliage and roots at the same time at your peril.

(Cut foliage and roots at the same time at your peril.)

What you are saying is that it is exactly the same for both pines and junipers (except one in brackets?) Why then is the distinction drawn between juniper having strength in FOLIAGE but pines in ROOTS?

I still maintain that almost all of the junipers and pines I take out of the grow beds are pruned both top and roots at the same time before potting up and they still mange to survive. By Ryan's view they should all die.

[PWC]

I take out of the grow beds are pruned both top and roots at the same time before potting up and they still mange to survive. By Ryan's view they should all die.

You obviously get the balance right between the amount of both top and roots removed so the tree continues unaffected.

[melbrackstone]

I've had a couple of junipers that have been both root-pruned and top pruned at the same time, and they've powered on ok in my climate zone... (until they died a couple of years later because of a non watering period whilst I was away for a week...my boys don't understand proper watering still..)

In saying that, Ryan lives in a much more challenging climate than most of us here, so I guess he's just telling it as it is in his area. To err on the side of caution could be his way, so that he doesn't get too much flack for telling everyone else in the world that you can do both at the same time? I dunno..

I'm guessing that most of us can make a statement that is true for us, but there'll always be someone who expects your technique to work perfectly for them, despite every other variable being different.

So my advice is to take everything you see and read as guidelines only.

Til then, try, try and try again until you get it right for you.

[wrcmad]

What you are saying is that it is exactly the same for both pines and junipers (except one in brackets?) Why then is the distinction drawn between juniper having strength in FOLIAGE but pines in ROOTS?

Yeah, I can see the confusion.
However, let me try to be more specific, with my interpretation:

Firstly, Ryan Neil's reference are all in the context of a well established, refined, potted bonsai tree - ie. grow beds and young developing trees do not count - they have relatively unlimited resources to build up strength, especially when in grow beds.

When decandling and needle plucking an established JBP bonsai, up to 70% of the foliage may be removed in one sitting. The strength in the roots allows the pine to burst into a second flush, and recover fully within the same growing season. If you were to repot this same tree concurrently to this heavy foliage removal... the result would be to weaken the tree. If this practice were repeated for several seasons in a row, the weakening of the tree could well lead to branch dieback, or even kill the tree.

For an established and refined juniper, removal of 70% of the foliage in one sitting would weaken the tree, if it did not cause dieback or even kill it. For established junipers, removal of 40 or 50% of the foliage in one sitting causes a stressful recovery, as the energy for recovery comes from the foliage itself. When repotting and root pruning, minimal foliage should be removed in the process to allow the strength in the foliage to aid the recovery to the roots. If both heavy foliage pruning and root pruning is performed at the same time, the tree will be weakened and result in detrimental health. As for pines, repeating this process several seasons in a row will weaken the tree even further.

[Snipz]

Hola,

I've made some wooden grow boxes from a hardwood pallet and plan to transplant them from nursery soil into a decent mix as soon as I get a chance.

Pines I'll leave them to there own devices as I want them to grow on and thicken
Juniper I'll leave until end of spring then do an initial styling and thin the foliage

Will report back and thanks again for your time in response