AusBonsai

After checking my soil pH a couple of years back I was told I was wasting my time by various accomplished bonsai growers around the world. It was stated that a soil pH was only an indication of what nutrients where available in the garden bed but as we where doing pot culture with plenty of fert added and the soil was refreshed every few years in general then it just did not matter about the soil pH in a pot. Yet the same was not said for azalea? This sounded pretty far out so as I said I cross checked with various unconnected growers and they came back with the same information.
Yet I still see a lot of talk about soil pH in bonsai culture from some accomplished growers.
Any ideas?

Because we in Bonsai are changing the potting medium every couple of years the pH does not matter a great deal but do becareful. People add Lime to Figs and African Olives but you would not do this to to Pines. A couple of years ago I had a nice white pine up near a fence. I slowly lost various branches and could not work out why. One night I saw the reason, a possum stopping to pee on the dog barking at it and hitting the Bonsai. The pH of the mix was under 4. The tree did not survive. What I am getting at, is along as you start with we neutral (6.5-7 ) mix, little can change unless you specially add ingedients to make it change.(eg: lime, potassium sulphate)

Yes, but not that much?

pH refers to the negative log of the concentration of hydronium ions, -log[H+] It is a logarithmic scale, so ph 4 has 10x more H+ than pH 5. pH 7 is considered neutral as that is the pH of pure water (being H OH). Water has a very small amount of H+ and OH- molecules in it. (0.0000001 moles of it)

pH has various affects in normal soil, primarily of most concern is the reduction of nutrient uptake by plants, but also of concern is aluminium toxicity which happens at approx pH 4. Organic potting mixes buffer themselves quite strongly,and because bonsai are watered frequently it is difficult for Hydronium ions (or acid ions) to concentrate enough to lower the pH. Accumulated salts can however affect the pH.

Some plants like acid soils and some don't. Azalea prefer an acid soil and will die if lime is applied to the them. Mineral based potting mixes are more susceptible to pH changes, but once again, the frequent watering tends to leach out any harmful chemicals.

Repotting the mix frequently has nothing to do with pH. A tree can live in a mix for years without any adverse pH changes.

pH is different from salinity, which is what can happen with soluble fertilizers.

Thanks for the great answers guys. I better do some more reading so I can understand your answers better.
I am not being sarcastic either thanks