AusBonsai

I got some JBP's just over a year ago as in this thread.

One rule, more of horticulture that Bonsai, that I broke at the time was that you should remove as much from the top as from the roots. I did get some advice at the time that some people did roots one year and tops the next, but in general it seems to be a strong rule in horticulture. This also applies to advanced landscape plants too that when planted out one should remove foliage to reduce stress on the tree. While studying horticulture we where given a paper written by an American horticulturalist who suggested this was not good practice. She said that if you give a tree a prune when planting out you encourage the tree to activate latent buds to produce new foliage to replace that which was removed. This may be the reason why some people think this is a good practice as they see activity on the tree. However, the author suggested that by leaving the foliage intact, even though you may not see much growth for some time, even for up to 2 years, the tree will be active under the ground establishing roots. This puts the tree in a better position to survive and thrive.

I can't say what works best for Bonsai as I have not had enough experience, but when I repotted these pines I left the tops except for removing a few strong candles near the top of trees. I removed over half the roots and from what little I read I thought they might struggle so I kept an eye on them ready to chop if I saw any set back. They were all very bushy and around 1m high. All thrived. Even the yellowest one was bright green within a few weeks.

So, was I lucky? Is the rule (guideline) not necessarily true? Do pines usually cope with this sort of treatment where other trees do not?

Current pictures show a loss of vigour more due to me being away, then ill, running out of water and then working long hours and so not providing great care for my trees.

The first one was quite yellow when I first purchased it. I'm not sure what to do with it. I may just plant it out and train it as a landscape tree. The second is one that I am looking to layer off some of the top branches and maybe some a little lower too. Refer to this thread for further details.

And the second rule was one I didn't realise I was breaking until it was too late.

The third pine from the above lot was much bushier and had nice short and compact leaves. I took it to my local club and other than it being suggested it would make a great christmas tree I was told the best thing to start off with was to chop it about halfway which is what I did. I got some growth in the lower section but as it was late in the growing season (early this year) not much happened and it sat back on the bench until a couple of months later I was looking for something to do and and went "I may as well just chop it back hard". It had very little foliage down low and that was on the end of lanky branches, but chop I did.

Then I read in a few places "Slowly, Slowly with pines". I though, "Oh well, It will probably die". Instead I now have this. I know its not much as far as a Bonsai is concerned, but I am amazed at the back budding and the compact candles and short needles.

As far as I am aware, With pines and Junipers, only reduce the Top or the bottom in a season.

Deciduous should be done both at the same time.

Ken

Some interesting observations. I have never heard slowly, slowly with pines so I routinely cut roots and tops in one go and have never had problems.
There are a number of Japanese recommendations for working with pines I have been puzzled about. I believe that pines here grow with much more vigour than in Japan so we can get away with more than they are able to.

I have also heard other horticultural gurus recommend to leave foliage intact when transplanting trees, arguing that extra foliage feeds the tree and helps roots re-establish. Makes sense to me but I have not been game to try it yet. When I repot established bonsai I don't remove ' same amount of top as roots'. How could you, there's not that much to spare? and the trees still thrive. I had put it down to regular foliage pruning through the year = root removal once a year but more likely your American Horticulturalist is correct and it is just not necessary to 'balance' root removal with foliage removal. We know that removing foliage does work but could leaving the top intact be better or just the same? - more opportunity for someone enthusiastic to do some trials.

Hi,

I consider that removing foliage when repotting has a bit more to do with the immediate post-repotting problems of a tree balancing water in versus water out. The pores in the leaves are where water is lost from, if there are a lot of leaves and not much roots then water out will be higher than water in, the plant will loose turgor and if it reaches a critical point, damage will be done.

cheers

Ash

These days I never reduce any foliage on just about every tree when I repot an established bonsai.That includes natives, conifers, evergreens and even deciduous trees in leaf.

With Junipers you must leave plenty of foliage on the trees at all times (the strength is in the foliage); with pines you can remove lots of foliage (the strength is in the roots); thats probably why you see lots of Literati pines but not junipers.

Grant

Hi Grant, Do you choose to repot when your natives or broad leaved trees have hardened off leaves? I have found Leptospermum and Antidesma wilt badly and get weak if the young shoots are left on and root prunning done together. Have you ever had this experience? The evapotranspiration rates where I lived were pretty high. Ash

Ash wrote:Hi Grant, Do you choose to repot when your natives or broad leaved trees have hardened off leaves? I have found Leptospermum and Antidesma wilt badly and get weak if the young shoots are left on and root prunning done together. Have you ever had this experience? The evapotranspiration rates where I lived were pretty high. Ash

I usually repot natives after the flush of spring and early summer; about now. I would have already lightly trimmed, as a matter of course, some of the growth.

However I don't remove foliage specifically to repot them; only very light trim if desired for shape.

You can tip prune if they are in growth and this is usually enough; here anyway.

Grant