After further review I have found the theory behind the cactus
mix
phenomenon here. Supposedly the coarse mix is bad for roots
because it
lets too much air into the root area. When it gets very hot
that air
heats up and cooks the roots. Whereas the dense cactus mix
keeps the
roots cool by staying wet and keeping too much hot air out away
from the
roots. By not allowing hot air to invade the root area the
extra
moisture keeps the roots cool when it's 100-plus degrees. This
is just
the opposite of what I have read elsewhere, that extra moisture
will
heat up the roots and cook them. Can anyone shed light on
this?


That sounds like nonsense to me. Water heats up fairly easily --
and then holds the heat for quite a while. A pot that sat in the
hot sun is gonna stay hot for a while even after the sun goes
down!

I'd always assumed any benefit it might have is simply to hold
more water in the pot in your very dry climate.

Jim Lewis - - Tallahassee, FL - Only where
people have learned to appreciate and cherish the landscape and
its living cover will they treat it with the care and respect it
should have - Paul Bigelow Sears.

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