Backbudding on White Pine Pinus Strobus

I am wondering if I should strip (older 2/3 year growth) needles to give my Pinus Stobus places to back bud or in five needle varieties is this achieved through candle pinching/pruning?

eugeniusgenx wrote:I am wondering if I should strip (older 2/3 year growth) needles to give my Pinus Stobus places to back bud or in five needle varieties is this achieved through candle pinching/pruning?

My experience with a dwarf variety is that needles need to be removed only to let light in. Buds seem to develop in the areas where the needles still are, similar to Mugos.

So one could say that it would be mugo like pinching that would encourage backbudding then?

eugeniusgenx wrote:So one could say that it would be mugo like pinching that would encourage backbudding then?

Yes.

However, mugos seem to back-bud much more strongly when candle pruned just as normally done with JBP and JRP (see Hans vanMeer's Karamoto web site). I knocked some candles off some of my landscape dwarf pinus strobi last year (May/June, IIRC) and wound up with radically reduced needles. I've done this again this year (June) to see if it happens again - the conventional wisdom is that needle size cannot be reduced on pinus strobus. At this point I cannot say that this candle removal causes more back-budding, but it seems reasonable because collapse of the auxin flow is 'universally' the key to initiating back-budding.

Pinus strobus
Be cautious, it is a 5 needle pine, techniques for 2 needle pines don't always work very well, and if you treat it like a JBP P. thunbergia you will likely loose any branches you decandle completely. Techniques for Japanese White Pine can work well for P. strobus. I have only gotten back budding on branches in zones where needles were still present. Don't remove needles where you want buds to form. This is largely true for JWP too, though the JWP is a little better at back budding. Yes, this also holds for some 2 needle pines, (mugo, ponderosa, etc) but it is safer to keep in mind that P. strobus is a 5 needle pine.

My P. strobus have been a disappointment because they have been continuously producing long internodes, regardless of treatment, reluctant to bud back, and very, very slow to produce bark on the trunk. The smooth immature bark just doesn't help produce the aged look. I have found going large, over 24 inches tall, it becomes a little easier to work with. Otherwise it is nice having a pine that the only protection I need to give them is to move them to a shady spot for the winter. Very, very cold hardy. Worth playing with, when the results are good (rare event) they are very good. I haven't gotten to the point of good results yet.

Yes. I can see some green bark and ultimately it only time that will cure it. Years. I have a few squat little shohin P. Strobus I have gotten in ditches. What happens here is they get chopped down every year by the big mowers and in winter they have snow piled on top of them. it is great insomuch as they are treated as if they were high up in the mountains in a way. One actually have grey bark already and a one inch thick little trunk! So excited for it in the next couple of years. i won't touch it the fall this year because I pulled it this year.
The better potensai i have collected are Red Pine, which also grow native here. I am going to trim some of the needles on the older growth where I need back budding on those. The great thing is that the constant trimming has already produced vibrant back budding on some of them. One of the Reds has a 5 inch thick trunk and stands around 16" tall . It seems to have survived the transplant and the new growth is opening up nicely.

Sounds like you have found some truly wonderful yamadori. I whole heartedly encourage you to keep working with them in spite of the oft repeated comments that P strobus is not good material for Bonsai. I was surveying my local roadside ditches, and did see some mowed shrubs that might have potential,. I am wondering what the legalities are for digging, especially along the interstate highway by me?

Best thing to do is either speak to the people that live there or to local districts and be up front with them, tell them what you are digging up gets mowed down every year anyway.

eugeniusgenx wrote:I am wondering if I should strip (older 2/3 year growth) needles to give my Pinus Stobus places to back bud or in five needle varieties is this achieved through candle pinching/pruning?

try cutting the new candle growth back just enough to still have the new buds emerge*, and, instead of stripping the needles, cut the needles at 1/2 to 2/3'rds where you wish buds to emerge. Strip the undersides and other areas where you do not wish buds, so that the needle sheath is damaged.
*also back two and three years into the growth if you can see adventitious buds that are forming. edzard

I used a technique from Herb Gustafson's book: Bonsai Workshop. (edit:3 years ago) I removed all of the buds from the tree, in spring as soon as they started to elongate. New buds formed a month or so later, next to the trunk on many of the branches including at the base of one of the first branches, with the results demonstrated on this thread.

I'll have to reread the technique to see if it is supposed to apply to white pines or if I just got lucky. I'd imagine you would only want to apply this technique to a tree with a fair amount of energy. My tree is still plugging along, although slowly. I was hoping it would develop a bit more this year since I re-potted two years ago, but I guess that is what I get for moving to a "real" bonsai pot.

I'm also curious what time of year would be ideal for needle cutting?

hi,
it looks like you are going to have to be the guiney pig and do some experimenting as very few answers are definative for the stobus variety. I have a few 5 needle pines and even defoliated one this year as an experiment (looking good so far too) but I have not ever worked with strobus so my advice would only be guess work as well.

do you have any other white pines - if so how does strobus compare? on a parallel here we have ordinary Scotts pine and 'dwarf' varieties that are actually more vigorous, make more buds and respond better to many bonsai techniques. If your strobus is similar you can do everything you'd do to a normal WP + more if you are confident of the trees health.

one thing that is 100% accurate though - auxins produced in the branch tips prevent back buds both forming and/or becoming stronger - this auxin production needs disrupting or you will never ramify the trees so you will need to work from the outside inwards, not just remove inner needles.

document it with pictures if you can - it will be interesting

thanks Marcus

To re-emphasize my experience with P strobus, the species in the original post, not any other species. Do not completely decandle the current year candles. You must leave at least a pair or more needles to develop, I usually leave 3 pairs. If you completely decandle, the risk is fair, that the branch will never produce buds and may die in a few years.

I learned this from experience in zone 5. Other climates the strobus might perform differently. I have completely decandled P strobus, the results were not uniform, I got good back budding in some vigorous zones, but lost completely some branches. Complete decandling is not a predictable nor reliable technique FOR STROBUS. If you need a branch in the future design do not completely decandle the branch. If a branch is a minor player in the tree's design, go ahead and decandle, sometimes the results are good.

Needles, yes back budding can happen on bare wood, BUT if you know you need P strobus (not any other pine) to produce buds in a region, leave the needles on that region. Back budding on wood older than 5 years is very poor, induce back branching on young wood before it ages past 5 years. Keep extra branches until you are certain you won't need them. Occasionally one gets lucky. I have gotten a single bud on 20 year old wood, but the bud was not where I needed it.

That is my experience with P strobus in the greater Chicago area. Elsewhere it may behave differently.
I think you have some great 'found in roadside ditch' yamadori, experiment, have fun with them. Do not push them too quickly to the Bonsai pot. Give them a year between major techniques, so they can remain vigorous. You are far enough north that you have a short growing season (less than 120 days). In short season areas it might be helpful to delay candle pruning to 30 days before average first frost date. The new candles won't sprout until spring, but your summers are likely too short to get 2 flushes of growth.
Hope my thoughts from my experience help.

By the way, all the techniques I mentioned relative to P strobus are techniques endorsed for Japanese White pine, which is why many just short hand their answers to questions about strobus to treat it like a JWP. However, keep the length of your growing season in mind, some JWP techniques won't work due to shorter growing season. I have written about what I have tried, there may be more techniques out there, but I have not tried them yet.

Leo Schordje wrote:To re-emphasize my experience with P strobus, the species in the original post, not any other species. Do not completely decandle the current year candles. You must leave at least a pair or more needles to develop, I usually leave 3 pairs. If you completely decandle, the risk is fair, that the branch will never produce buds and may die in a few years.

Hope my thoughts from my experience help.

Leo,

Thanks for your account of your experience. I want to be sure that I understand you are saying 'a pair' of needles fascicles of this 5-needle pine. While I am still a bit reluctant to totally decandle, I find it remarkable that one to three new fascicles is enough to preclude possibly killing a branch. But it is what it is. Again, thanks.

As I mentioned earlier in this thread, I did some selective decandling this spring on my dwarf EWPs after scales were well defined and needles just beginning to emerge. New apical buds were expressed about 5 weeks later, but I have no signs yet of any associated back budding (I expect that these may not be apparent until fall or next spring - do you have any insight?).

yes, I did mean leaving several pairs of needle fascicles, and since I don't remove many older needles, there are always many needles to support a branch. Stripping a branch to only one or two needle fascicles would not be good for the health of that branch. That is not what I meant.

Your photo shows what I would expect from candle pruning early in the year. You get a few buds right away, not much back budding at that time, though more will occur the following spring. I really do hold off on candle pruning until the fall of the year, at that point it is more like fall branch pruning of the current year new branches, since the candles are fully expanded by then, the candles really have become the branch extension for the season. Then in spring I have a much heavier selection of buds on the previous season's growth. I do remove excess buds early in spring before candle extension to direct extension, removing the center bud where I want a change in direction of branch extension. I also remove buds pointing down or up where I want horizontal extension.

That is what I do. I do need to add, none of my white pines (strobus) are ready for prime time. So others may have better technique. I launched into this thread because the majority of the responses you were getting were from other's experience with species other than strobus. You might email Jim Doyle or Ted Mattson, both are bonsai professionals and get their thoughts. Jim Doyle in particular has a very nice strobus that he has exhibited and the tree has taken best in show in Chicago some years ago. But Jim grows in zone 6 or 7, with a much longer growing season, so keep this in mind when you get his response. http://www.natureswaybonsai.com/

I have a bunch of strobus which I am trying to please.  This is one of the older ones.  I will say that the needles have shortened but only to the weakening of the tree.  I'd like back budding and denser foliage but then you are fertilizing more and sacrificing the short internides and shorter branches.  I'm trying with some younger ones to develope them more like one would a deciduous tree.  Thrying to grow them fat with lots of branches and save the ramifications for a two or three year process, shrinking the needles and internides.  It weakens the tree considerably though and branches can wither.  Feeding heavily in the fall is my next best idea to setting up buds for the spring.