Another note on pots
Paul Tyerman (Sat, 30 Oct 2004 13:05:26 PDT)

At 01:26 30/10/04, you wrote:

Dave,

The one problem with white or light coloured pots in our conditions at
least is that we get extensive algae produced inside the pot due to the
light penetration. It can be quite damaging to the root systems of some
plants as it seems to bind the soil together and stop water from permeating
the soil as well. I have bought things in small pots that are pale
coloured and when repotting found that the whole root ball when dropped out
is covered in a green film, which is quite solid when trying to tease the
roots out. It is at least worth mentioning this for environments where the
sun is fairly strong.

The other problem with white pots is that they do not last as long as black
pots (this applies to any colour other than black). The process of
colouring (well at least here in Australia anyway) makes a plastic that
degrades at a quicker rate, so I find ithat n our conditions smaller
non-black pots tend to start becoming brittle within 3 years or so
(sometimes quicker), whereas black pots last for at least twice that. This
is not my imagination as I have talked to suppliers about this and there is
scientific backing for this. I know a plant wholesaler near here who will
not use anything but black pots, as they have less than half the life of
the black pots in their conditions.... which tends to add up when repotting
and reusing pots as often as wholesalers do.

I agree with your temperature comments though..... it is just that you have
to weigh up the pros and cons of the other side effects of the coloured pots.

Cheers.

Paul Tyerman
Canberra, Australia. USDA equivalent - Zone 8/9

Growing.... Galanthus, Erythroniums, Fritillarias, Trilliums, Cyclamen,
Crocus, Cyrtanthus, Oxalis, Liliums, Hellebores, Aroids, Irises plus just
about anything else that doesn't move!!!!!