AusBonsai

After buying a pH kit a few years ago I posted my results on an international Bonsai Forum and was told that PH in a bonsai pot does not matter. Something about the PH is only of concern in ground soil as it is an indication of what nutrients are available and as we are always adding nutrients to our bonsai soil and changing the soil regulary thyen it does not matter.
This was confirmed by several other experienced growers. Azalea is an exception to the rule which always has me wondering if they are correct.
So is PH an issue?

im not sure how much of an issue it would be but i beleive if it is to acidic or to alkaline it would definately have an effect on the tree in the long term, if it didnt matter then why do trees that prefer an acidic soil do not do well in an alkaline soil?? it definately puts the thought there doesnt it. i will be interested in hearing from others that may know a bit more

I have never tested my soil for PH. What I do is listen to the tree's. Or in this case watch, if I notice something is not right I find out what it is the tree is deficient of.

Then and add some most Chemical fertiliser's have a balanced amount of macro and micro trace elements in them. So it should balance your PH well.

There are a lot of proponents of organic fertilisers, which is good also, but there is the hit and miss of the elements needed for the plants health.
So maybe testing the PH then might be wise.

Most natives like it slightly acid, the ones I grow do any way. So I use a fertiliser that suits Azaleas.

Just my opinion, cheers Pup

I find the statement "it doesn't matter" very perplexing.

It does indeed matter, perhaps not so much if you are adding correct nutrients at correct intervals.

Like Jamie has already stated, if you plant species enjoy either an akaline or alternatively an acidic soil then letting you nutrients head to the opposite zone, will have a detremental effect to the soil. Your plant will get sicker and sicker until the PH is returned to the level it likes most.

I understand and agree with the others you have spoken with, yet they are making a blanket statement that makes you assume it does not matter at all, it does when it gets into the extremes.

Believe me. It surprised me when I first heard it and expected others that I asked to say the first person that told me it was Nonsense but Every experienced Bonsai practitioner I asked on the international forums told me this is so.

Worst sentence in the history of English

In my experience, everything I do (watering and feeding) sends the mix sour (acidic)
If the mix is too acidic, even when food is available, the trees can't access it.

To sweeten the mix, or to make it more alkaline, I add dolomite.

This not only sweetens the mix but it gets the micro organisms going

My trusty ph kit from bunnings gets lots of use.

Cheers

Lindsay

how long does the dolomite last for lindsay? what i know of dolomite is differing as some people call it road base or crusher dust? is this the same stuff?

i take it you use it as a potting mix medium?

It's interesting you bring that up Lindsay. I followed your advice a few years ago and put a good solid layer of Dolomite on my soil. It clogged it up more than my liking as it was a dust that I used. Maybe just a personal thing in how I like my soil but is it a dust you use?

The most interesting part though is I repotted almost everything the next spring except a couple and I found that no matter how much I fertilised these couple that where still in the soil with Dolomite They would not stop being nutrient deficient.
I repotted one the year later which was a little Amur maple I was training root over rock and was not expecting much as it always had little growth with chlorosis. But when I unearthed it I found great root growth which is something you suggested from using Dolomite.

Bretts,
When you say

The most interesting part though is I repotted almost everything the next spring except a couple and I found that no matter how much I fertilised these couple that where still in the soil with Dolomite They would not stop being nutrient deficient.

Do you mean the trees were growing vigorously, or not at all?

Cheers
Lindsay

I dont worry about pH here in sydney. Our water is pretty good, and we get enough flush outs with rain to keep it fairly stable. I use organic fertilizers but try to minimize the chook poo as this raises pH. I dont ever add sulfur or dolomite. But i HATE azaleas.....

Brett, this is an interesting chart that shows the solubility of the macro and most abundant micro elements at different pH levels. Also, it is good to remember that pH is just the amount of hydrogen ions in a solution, nothing else. It determines how soluble certain elements are, nothing else really.

http://hawaiianhorticulture.com/Images/ ... bility.jpg

Joel.

cheers for the link Joel. interesting stuff, i am starting to understand that a bit now

its interesting to see that certain elements are taken in better at lower or higher PH levels.

Thanks Joel. That sounds interesting I will look into that.

Lindsay
Do you mean the trees were growing vigorously, or not at all?

They grew like a nutrient deficient tree. Not very much at all.
One thing I would add is that after repotting I found the amur maple came out nutrient deficient (sorry for layman terms) but returned to normal soon after. In this I mean it leafed out with alot of yellow in the leaves but in time with fertilising it returned to normal. I figure it was running on the nutrients of the previous year and it took a while to return to normal in the new soil in spring. Yet when it was in the dolomite treated soil I could not get rid of the yellow.
Just to clarify your question there was little top growth so I was very surprised to find there had been plenty of growth under the soil when in a soil that was treated with dolomite.

Thanks for clarifying that Bretts.
I haven't grown amur maples for years. When I did, they would rush to a premature spring growth then the soft leaves would
burn with the next cold snap. When the hot summer sun touched them they would burn again. I couldn't get any vigour out of them.
Do they grow vigorously where you are?
Jamie, It is probably the same stuff that you know as road component. The oldest pine in the world is growing in 99% dolomite.
I apply it abundantly. It isn't intensely powerful. I've given Japanese Maples 3 liberal coatings (2cm over the surface) in a growing season. Your water supply in NSW may be supplying adequate sweetening. I have overdone it at times. But that's how you learn.

Cheers
Lindsay

Yes some elements are taken in better at different pH levels. Also some fertilizer chemicals may be more or less soluble at different pH, can even form insoluble compounds and be useless to your plants.

thanks lindsay, i thought so.

im in QLD by the way not NSW. all good though

jamie