This is not powder, it is jin seal, lime sulphur. It is applied as it would be over old deadwood, full strength. I take it as it comes in a bottle and add water 1:1. This is applied with a big painting brush.
Purpose: The great smaller outer surface roots which I discovered were all sitting under the soil line. Therefore their color was quite dark even blackish - at least very different from the rest of the nebari which was exposed to sun and rain. this will be overcome eventually by itself. But it would take ten years or more. The lime sulphur bleaches the bark of the fine roots and crates an overall patina looking feeling which is credible.
Just look at the pictures after this up to today. One can not see that the smaller roots were black when I found them.
The question is asked all over social media: Aha, understand, but I would never dare to do this because it will hurt the roots and especially the mycorrhiza.
Answer: No it will not, just look at the following pictures. It might disturb or even kill mycorrhiza, yes. Did you know that maples do not need mycorrhiza in a bonsai pot? Mycorrhiza helps wild trees which are in locations where they do not have easy access to some forms of minerals. Mycorrhiza breaks existing minerals down into forms that are acceptable to the tree. Trees in captivity are being fertilized with al this and the garden does the job of the mycorrhiza. Mycorrhiza also sometimes helps trees to stand long periods of draught. again the gardener does that job.
And then, do not underestimate the toughness of mycorrhiza. You might kill it with lime sulphur. But after a few months it's back.
Anyway, I apply it to ALL small roots of ALL of my better broadleaved trees with best results. Just look at my progressions.
Another bonsai myth debunked.
