Last year, I read (somewhere -- this is the problem with having
too much bonsai reading material, finding something again ;-)
that a good way to get rid of the limy deposits around pot rims
is to bury the pot for a year or so.

So I did.

The year was up day before yesterday (but since we had a big
storm here yesterday in which I lost the top 1/3 of a 100-foot
pine out in the pasture, my report got delayed a day or so).

In short, it seems to work, though I won't call the findings
definitive yet.

I buried (in one of my large grow boxes where assorted cuttings,
seedlings, and other "stuff" also live) two small (mame/small
shohin size) pots that had heavy deposits of lime around the pot
rims. Both pots were blue, with a gloss glaze -- but one of them
was quite a bit shinier than the other, which was almost a velvet
matte gloss. The insides were unglazed. Both are of Chinese
manufacture -- I think, though the matte pot may be Japanese.

The soil was quite heavy -- a mixture of various old bonsai soils
and horse-manure compost that I use in my grow beds (which get
almost NO fertilizer over the years). After a few years, the
compost breaks down into a very mucky substance. This was my
oldest grow box, and is so rotted now, that it will be "retired"
this year. Anyway, this was real goop that these pots were
buried in. (Growing around them were a dozen azalea cuttings (now
in pots) two dozen bald cypress cuttings (ditto), several large
buttonbush cuttings (undecided), two small black cherry trees,
and a BUNCH of privet cuttings that I don't know what I'm going
to do with.

As I said, the calcium deposits on these pots were heavy -- very
unsightly.

Results: The pot with the semi-gloss, matte-like finish still
has signs of calcium in a few spots around the rim. The bottom
(unglazed, outside and inside) still has quite a bit of calcium.
But the pot is in useable (and showable) condition.

The high-gloss pot is virtually calcium free on the glazed
portions. Again, there still are signs of calcium on the
unglazed portions.

I suspect that if I had left them in the soil for 18 months, the
calcium on the glazed parts of both pots would be gone.

I'm going to expand and extend the experiment this year, using
two brown, matte-finish, pots (much larger) that are caked with
several years' worth of calcium magnesium carbonate (which is
what my well water leaves behind when it evaporates) deposits. I
will bury them in my FRESH compost pile and let them ferment as
the compost ferments, unveiling them a year from this week (or
whenever I get them buried). Look for another report then.

Meanwhile, it seems possible to me that glazed pots can be
decalcified by burying them in soil and leaving them there for a
year or so. Since I have never found any of the home remedies
that makes a dent on the stuff that cakes pots around here (and
I've tried them all!), I plan on having pots buried in my grow
boxes on a regular basis from now on.

I will be watching to see if I can determine any significant
differences between the amount of calcium that is formed on pots
with different kinds of glazes and the relative ease with which
burying de-calcifies them. I have long thought that certain
glazes tend to "attract" deposits more than others, because I
have several pots that never seem to get the stuff caked on them,
and others get it easily.

If anyone else would like to do similar studies, it should help.
I'd especially like the potters among us to look at the glaze
aspect. Note: I have a couple of Mike H's pots, and they both
seem to gather calcium deposits more quickly and deeper than
others (a yellow-brown glaze, and a light blue-green glaze).

Now, if I could only remember (or re-find) where I read about
this in the first place!

Jim Lewis - - Tallahassee, FL - Our life is
frittered away by detail . . . . Simplify! Simplify. -- Henry
David Thoreau - Walden

************************************************** ******************************
++++Sponsored, in part, by Evergreen Gardenworks++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++