Developing compact "scale" foliage

[Eric Group]

Fr species like say Procumbens Nana or Prsons or even San Jose it seems... There can be a real issue developing the tight, mature scale foliage uniformly even on very mature trees.

So, what is the best practice here- I know grafting Kishu or Sipaku foliage is an option, but what is the real technique to bring on the mature growth naturally?

I have been told in the past just to remove as much of the needle foliage as possible, leaving mostly the scale... In my experience it Doesn't seem to work though as commonly the new growth will just revert to the juvenile growth again.

I was told recently that if the root mass is greater than what is needed to support existing foliage, that will cause the juvenile growth...so, then does that mean we have to prune the roots every time we prune the foliage?

Is it about the amount of sun or amount/ type of fertilizer the tree receives?

Obviously this isn't as big of an issue with Simpaku, Kishu, itiogawa... Just wondering how people normally address it with the trees that do need a little more work to develop that coveted mature growth.

 

[Dav4]

It's my understanding that the presence of needle foliage is either secondary to genetics (San Jose) or secondary to stress. Improper or excessive pruning seems to be the most likely inciting cause for scale foliage to revert to juvenile, though recent re-potting or high fert regimens may be predisposing factors, as well. With this in mind, it would make sense that keeping the trees happy and practicing good horticultural technique would go a long way toward keeping healthy scale foliage on the tree.
I can't speak about procumbens, but I've been working a San Jose for a while, and it has never had less then 90% needle foliage, regardless of fertilizer, pruning or lack there of, etc.. Solution...remove the scale foliage and keep it 100% needle. It's worked for me, and I'm pretty sure this is what Colin Lewis recommends as well.
Right now, I'm having a similar issue with 2 of my collected Rocky Mountain Junipers. The foliage they've carried had been mostly mature until the last year or two...they've both been re-potted as well as heavily wired and pruned annually. My plan is to back off on the frequency of pruning and fert slightly and see what this does. I also cut down 7 trees near my benches last fall as they'll get an extra hour of AM sun now which always a good thing with junipers.

 

[Poink88]

From what I've read.

Juvenile foliage is produced because it is faster or easier for the plant. It is usually temporary though because it is less efficient. So once the tree have enough to sustain itself, they start producing the mature foliage which is harder (more "costly") to produce but more efficient and offers better return in the long run.

IF this is correct then the key is not crossing that threshold "of having enough foliage" if you want to avoid juvenile foliage. Problem is some plan produce it more than others and I have no idea if your plant is on the "touchy" group.

 

[A Random User]

I have found here in Florida that most junipers will usually turn to
scale very easily with a lot of sun and little water. Only exception for me
has been with San Jose... which as Dave has said, likes to maintain it's
needle foliage.

 

[Vance Wood]

I have found here in Florida that most junipers will usually turn to
scale very easily with a lot of sun and little water. Only exception for me
has been with San Jose... which as Dave has said, likes to maintain it's
needle foliage.

I have called the San Jose Juniper the Peter Pan Juniper, it won't grow up and it's pretty prickly about saying so.

 

[Vance Wood]

Fr species like say Procumbens Nana or Prsons or even San Jose it seems... There can be a real issue developing the tight, mature scale foliage uniformly even on very mature trees.

So, what is the best practice here- I know grafting Kishu or Sipaku foliage is an option, but what is the real technique to bring on the mature growth naturally?

I have been told in the past just to remove as much of the needle foliage as possible, leaving mostly the scale... In my experience it Doesn't seem to work though as commonly the new growth will just revert to the juvenile growth again.

I was told recently that if the root mass is greater than what is needed to support existing foliage, that will cause the juvenile growth...so, then does that mean we have to prune the roots every time we prune the foliage?


Is it about the amount of sun or amount/ type of fertilizer the tree receives?

Obviously this isn't as big of an issue with Simpaku, Kishu, itiogawa... Just wondering how people normally address it with the trees that do need a little more work to develop that coveted mature growth.

Don't deal with the trees that are this problematic. Once you have the Shimpakus in your stable with the exception of the Sabina and a couple of others unless you don't mind stimulating the juvenile as a preference they are just not worth the effort. JMHO

 

[edprocoat]

I think the key is a combo of time and sun/fertilizer. I notice when you get mature foliage and if you trim back to get it to branch out the new stuff naturally comes out juvenile while the older mature foliage reverts to juvenile to push that new growth. I agree the San Jose is a "Peter Pan" as Vance so sagely described it. I bought a really old one this September and its loaded with "old?" juvenile foliage.

ed

 

[bonhe]

Talking about physiology, needle foliage is needed to help the tree grow faster. Why? Needle foliage has stomata open to the air; by that, photosynthesis will be much better.
Scale foliage has many stomata hidden from the air.
Bonhe

 

[discusmike]

I agree with Vance, I'm all for team shimp, the rolls royce of juni's.

 

[jkd2572]

I have two San Jose junipers. Their foliage is what it is. Never seen anything but needle foliage. I have actually taken to literally shearing them about twice a year. They have developed very thick pads by doing this.

 

[Jaberwky17]

I just got a nice fat trunked San Jose from George Muranaka and was pleasantly surprised to see that it actually has a majority of mature foliage when it showed up. Curious to see if that changes when it starts going outside and gets used to Minnesota weather versus California.

 

[Eric Group]

Don't deal with the trees that are this problematic. Once you have the Shimpakus in your stable with the exception of the Sabina and a couple of others unless you don't mind stimulating the juvenile as a preference they are just not worth the effort. JMHO

I understand where you are coming from Vance, and I have a Kishu and Another Shimpaku I bought recently that I am sure will provide the preferred type of growth with a little less work... I do also own a Parsons though that I bought about a year back just because it has a big trunk with some decent movement and I have seen people make beautiful trees from them! I own a "regular" Sargent Juniper- I have read Shimpaku is basically a variation of the Sargent with tighter, more compact foliage (is that true?) and I can see a relation there, but the Sargent's have much more stringy/ coarse growth... Still they do develop a nice scale look at the tips and even the needle growth is not nearly as sharp and prickly as the Parsons... They have bright green, beautiful foliage... I guess I am just asking about the procedures for developing the scale foliage because I don't want to just "give up" on the trees I already own... Same with a couple Procumbins Nana I own.. Even their needle foliage is so small and compact, they look good without the scale foliage, but the look BEST if you get them to produce that mature growth... That is why I am asking for a little direction...

Going forward I plan to probably stick touring and propagating the preferable species like the Kishu, Itiogawa, Shimpaku... (I still get confused there too- are Kishu and itiogawa variations of Shimpaku, or are Shimpaku, Kishu, and Itiogawa all slightly different varieties?)... I haven't done a bunch of grafting, and what little I have attempted years ago was not successful, AND grafts tend to leave scars unless you are very good at it so that isn't the route I plan to go right now, but maybe if I get someone to showme a little more about how to do it correctly I can just graft some new foliage on some of these trees that I already own... "One day"... For now I was just hoping to try to bend them to my will! Lol

 

[Brian Van Fleet]

(I still get confused there too- are Kishu and itiogawa variations of Shimpaku, or are Shimpaku, Kishu, and Itiogawa all slightly different varieties?)

Botanically, they're all just Juniperus chinensis. Shimpaku/shin-paku is a nickname, literally translated it is "authentic oak", which means "the genuine article".

Kishu and Itoigawa are regions in Japan where junipers are found to have some distinguishable different visible characteristics.

It seems kishu and Itoigawa have effectively become cultivars based on these characteristics, but probably not formally, mostly among our small bonsai community.

 

[Cypress]

Fr species like say Procumbens Nana or Prsons or even San Jose it seems... There can be a real issue developing the tight, mature scale foliage uniformly even on very mature trees.

Errrrm, Procumbens Nana pretty much always stays as juvenile foliage... so if you're waiting around for your Procumbens to change to mature foliage, it's not going to happen.

 

[Vance Wood]

Errrrm, Procumbens Nana pretty much always stays as juvenile foliage... so if you're waiting around for your Procumbens to change to mature foliage, it's not going to happen.

I used to think that too, but the truth is they do produce what we call adult foliage, but; it is more difficult to get the tree to do it and keep it than it is to accept it as the other way round.

 

[KennedyMarx]

I have seen mature foliage on procumbens while prowling nurseries looking for junipers. I couldn't imagine trying to get the entire foliage mass to take on that characteristic. The advice I've read has been to just use the needle foliage on them.

 

[Cypress]

Yea, I've heard it may appear but it seems the chances of whole tree becoming adult foliage seems slim to none.

 

[Vance Wood]

Yea, I've heard it may appear but it seems the chances of whole tree becoming adult foliage seems slim to none.

That's why I wrote what I posted to your original question. I also agree that San Jose Juniper shows the same tendency to juvenile foliage. So I guess the vital question is whether or not you prefer the juvenile foliage to the so-called mature foliage or is there a place in your thinking for both? My preference is to have Junipers I do not have to fuss over just for the sake of the foliage they produce.

That is why I prefer Kishu over Itoigawa, I don't have to bribe, cajole, or apply some esoteric cultural secret to maintain adult foliage. Also as far as Procumbens and San Jose are concerned: I do not find the juvenile growth of the Procumbens objectionable and if trimmed (dare I use the word pinched) properly they are quite beautiful. The San Jose, with adult foliage, in my opinion looks trashy, so again I prefer the juvenile foliage which is very much my preference.

Just a personal observation and not intend to make a statement of "This is better than that", it seems that there are some growers of bonsai that are more interested in seeing if they can make a particular tree produce adult foliage than the finished image of the tree they are trying to create.

 

[Cadillactaste]

This had me wondering of the foliage of my Procumben Nana as it matures, and the foliage it will have. This is what I found...so the procumbens nana is a "dwarf" variety. And will typically always toss out what we consider needle leaf. And the shimpaku will mature with scale leaf. Only procumbens will occassionally toss out scale. But won't typically turn that direction once mature. But...the scale leaf on a mature shimpaku can throw needle leaf but will eventually turn scale. "If" I am reading this correctly.




http://absolutebonsai.com/wiring_and_thinning_junipers

The two most common types of juniper are procumbens nana (dwarf Japanese garden juniper) and shimpaku. Conveniently, these also represent the two types of foliage found on junipers; needle leaf and scale leaf. Needle leaf is considered to be juvenile while scale leaf is considered to be mature. A stressed shimpaku will produce needle leaf foliage and then return back to scale leaf. Conversely, a healthy procumbens will stay as needle leaf, occasionally putting out the odd scale leaf. There is no concern when this happens.

 

[Vance Wood]

This had me wondering of the foliage of my Procumben Nana as it matures, and the foliage it will have. This is what I found...so the procumbens nana is a "dwarf" variety. And will typically always toss out what we consider needle leaf. And the shimpaku will mature with scale leaf. Only procumbens will occassionally toss out scale. But won't typically turn that direction once mature. But...the scale leaf on a mature shimpaku can throw needle leaf but will eventually turn scale. "If" I am reading this correctly.




http://absolutebonsai.com/wiring_and_thinning_junipers

You are for the most part correct. However there are those today who would for one reason or another be critical of anyone desiring to keep a Procumbens in juvenile foliage. My preference is: I like the juvenile foliage and it is so easy to keep it that way why not cultivate it that way? But---that's just my opinion. Just because you can churn cream into butter does not mean there is no use for cream?

In the quest to make credible and beautiful bonsai we consistently make trees do things they may or may not do naturally. Things like producing compact foliage pads, small leaves and small needles with short internodes. We make upright designs from trees that in nature would lay on the ground, we make tall tree images out of trees that would in nature be bushes so on an so forth. The entire art of bonsai is for lack of a better term surrealistic in nature. We are trying to create the images of age and size and encounters with weather in little trees that, in many cases, have no genetic link to what they mimic. Understanding this I find it difficult to suggest that somehow those of us who prefer juvenile foliage on some trees are doing it wrong. As long as you, me, or the Man-in-the-Moon understand that they have a choice, that choice should not be called into doubt or criticism. Thus endith the rant.