Well-drained growing media (was Oh No! A Boophone disaster!)
totototo@telus.net (Tue, 06 Oct 2009 17:26:13 PDT)
On 5 Oct 2009, at 18:02, Leo A. Martin wrote:
I have wanted to try some of the larger-particle perlite, often used for
insulation, but I have been warned much of this is very high in fluoride
and toxic to plants.
Change that "is" to "may be". If you feel you must use insulation grade perlite
in spite of these warnings, you can mitigate the risk by adding lime to the mix
as calcium fluoride and magnesium fluoride are very insoluble and thus the
presence of Ca++ and Mg++ ions in the soil will tend to soak up any F- released
by the perlite.
--
Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate
on beautiful Vancouver Island