Acid Reflex

I have several acid loving plants- I am adding Sulfur to lower the PH, problem is all the proportions are given on a yard scale. Does anyone know some helpful general proportions for bonsai scale? How much of that stuff does it take to lower 1 PH in a small (<gallon) pot? Also does it hang out or do you need to reapply it every so often to keep the PH down? Thanks for the help- one of these days I will post bonsai instead of questions, but I need to get bonsai first- that required questions. kind of a chicken and an egg.

By acid loving, do you mean azaleas, rhododendrons, heathers? I grow all of these in a standard bonsai mix but fertilise only with ericaceous plant food such as Miracid or Miracle Grow Acid Plant Food. I've never found a need to alter mix pH in 20 years.

To answer the second half of your question, the sulfur treatment is temporary. It is very hard to keep soil acidity up chemically.

You could add peat (or sphagnum) to you soil to up its acid content a bit but the best solution is Kevin's -- fertilize with a fertilizer designed for azalea.

My acid loving friends are dogwood, Black Cherry and a yellow Birch (debate the suitability of these as bonsai another time). I have been fertilizing with Hollytone- is that all it takes? The Black Cherry apparently wants a PH under 5- will the Hollytone alone do this?

In pots, these species don't need an "acid" fertilizer. The standard "balanced" Miracle-Gro is fine for them.

Often the acid type fertilizers (Mir-Acid) have additional micro-nuttrients that azaleas and conifers like such as sulphur and iron. Don't worry about the soil mix - just use an acid type fertilizer like Miracid. I personally like time release Dynamite for Azaleas.

Frank

Thanks for the responses- Just for my own knowledge how does the acidity of the soil not matter in the same way it would in the ground- I know a pot isn't the ground, this point is hammered home, but if a plant needs say a PH of 5.5 to absorb nutrients correctly in the ground why does it not need such to do the same in a pot?