GardenBanter.co.uk

GardenBanter.co.uk (https://www.gardenbanter.co.uk/)
-   Gardening (https://www.gardenbanter.co.uk/gardening/)
-   -   Glazed pots not good for vegetable plants??? (https://www.gardenbanter.co.uk/gardening/82243-glazed-pots-not-good-vegetable-plants.html)

Layne 23-08-2004 05:38 AM

Glazed pots not good for vegetable plants???
 
Just checking,

I saw a glazed pot at Target and on the bottom there was a sticker
that said that pot was not for food use or something like that. Does
that mean I shouldn't grow vegetable plants in it? And if so why?
And...does this apply to all glazed pots? I'm asking because I'd like
to grow kitty grass for my cats in a glazed pot I already have (not
the one I saw at Target with the sticker on the bottom.

Stupid question over,

Layne

ps, thanks!

zxcvbob 23-08-2004 06:04 AM

Layne wrote:
Just checking,

I saw a glazed pot at Target and on the bottom there was a sticker
that said that pot was not for food use or something like that. Does
that mean I shouldn't grow vegetable plants in it? And if so why?
And...does this apply to all glazed pots? I'm asking because I'd like
to grow kitty grass for my cats in a glazed pot I already have (not
the one I saw at Target with the sticker on the bottom.

Stupid question over,

Layne

ps, thanks!



It probably means the glaze contains lead, or they don't know if the
glaze contains lead. Lead is not particularly mobile in soil, I would
not worry about it; I might mix some crushed limestone with the potting
soil to make sure the pH is not too low, but it's not like you were
drinking orange juice or lemonade stored in the pot.

Best regards,
Bob

Pam - gardengal 23-08-2004 06:12 AM


Layne wrote in message ...
Just checking,

I saw a glazed pot at Target and on the bottom there was a sticker
that said that pot was not for food use or something like that. Does
that mean I shouldn't grow vegetable plants in it? And if so why?
And...does this apply to all glazed pots? I'm asking because I'd like
to grow kitty grass for my cats in a glazed pot I already have (not
the one I saw at Target with the sticker on the bottom.

Stupid question over,

Layne

ps, thanks!


Some pots have low fired glazes comprised of toxic compounds which could
leach into food products. They are not intended for food for human
consumption to be served in. There is no problem with using these for
growing cat grass, although I might not consider them very good for other
vegetable crops you intend to eat. For one thing, they tend not to be very
durable and will not weather well outside. They also tend to be cache pots
with no drainage holes - a decorative item you put another pot into - so
they look like they could be used as a serving piece. Pots and ceramic
containers designed for growing plants out of doors generally are high fired
and have no similar concerns.



Phisherman 23-08-2004 04:50 PM

On Sun, 22 Aug 2004 20:38:38 -0700, Layne wrote:

Just checking,

I saw a glazed pot at Target and on the bottom there was a sticker
that said that pot was not for food use or something like that. Does
that mean I shouldn't grow vegetable plants in it? And if so why?
And...does this apply to all glazed pots? I'm asking because I'd like
to grow kitty grass for my cats in a glazed pot I already have (not
the one I saw at Target with the sticker on the bottom.

Stupid question over,

Layne

ps, thanks!


The porous clay pots are better choices for plants because they allow
more air to the roots. Glazed pots would be a good choice for bog
plants. Some glazes contain toxic or even radioactive (!) compounds.

Doug Kanter 23-08-2004 06:15 PM


"Phisherman" wrote in message
...
On Sun, 22 Aug 2004 20:38:38 -0700, Layne wrote:

Just checking,

I saw a glazed pot at Target and on the bottom there was a sticker
that said that pot was not for food use or something like that. Does
that mean I shouldn't grow vegetable plants in it? And if so why?
And...does this apply to all glazed pots? I'm asking because I'd like
to grow kitty grass for my cats in a glazed pot I already have (not
the one I saw at Target with the sticker on the bottom.

Stupid question over,

Layne

ps, thanks!


The porous clay pots are better choices for plants because they allow
more air to the roots. Glazed pots would be a good choice for bog
plants. Some glazes contain toxic or even radioactive (!) compounds.


Even more interesting is that many of the pots for sale these days come from
China, where anything goes as far as environmental safety. The rap goes
something like "Economic growth trumps minor issues like safety".



Layne 25-08-2004 04:48 AM

Thanks for the responses. :-)

Layne

Beecrofter 27-08-2004 12:01 AM

Layne wrote in message . ..
Thanks for the responses. :-)

Layne


Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and store.

Layne 27-08-2004 07:18 AM

On 26 Aug 2004 15:01:04 -0700, (Beecrofter) wrote:

Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and store.


I'm curious. Do *all* glazed pots have harmful substances in the
glaze? I mean we eat and drink from glazed cups and bowls?... Is there
any way of knowing if a glazed pot contains harmful substances?

Layne

Paulo 27-08-2004 01:27 PM

The use of glazes is regulated. In general dont trust in cups or bowls with
bright colours as reds or yellows. Particualrly if the bowl or cup is made
as decor object. You can put lemon juice in them, if the glaze loose the
finish, then could be possible be toxic

--
Paulo
Layne wrote in message ...
On 26 Aug 2004 15:01:04 -0700, (Beecrofter) wrote:

Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and

store.

I'm curious. Do *all* glazed pots have harmful substances in the
glaze? I mean we eat and drink from glazed cups and bowls?... Is there
any way of knowing if a glazed pot contains harmful substances?

Layne




zxcvbob 27-08-2004 03:36 PM

Paulo wrote:
The use of glazes is regulated.


Crayons are regulated too, but that didn't stop the Chinese from using
lead pigment in crayons and selling them to the US with fake "ASTM"
safety markings on the box. That was about the same time we made them
"most favored nation" trading partners...

Best regards,
Bob

J. Del Col 27-08-2004 04:31 PM

Layne wrote in message . ..
On 26 Aug 2004 15:01:04 -0700, (Beecrofter) wrote:

Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and store.


I'm curious. Do *all* glazed pots have harmful substances in the
glaze? I mean we eat and drink from glazed cups and bowls?... Is there
any way of knowing if a glazed pot contains harmful substances?


Commercial glazed ceramic ware for table use is fired at high enough
temperature to burn out the lead and other metals. There are lead
test kits available if you are worried that your dinnerware or
flowerpots might be contaminated.

About 50 years ago Fiesta Ware produced a red glazed ware that was
made with uranium salts in the glaze. It was radioactive, but it was
not really dangerous as long as you didn't use it frequently with
strongly acid foods.

Pieces of it are valuable items now.


J. Del Col

Paulo 28-08-2004 01:52 AM

Dont you have testing labs for imported goods ?

--
Paulo
"zxcvbob" wrote in message
...
Paulo wrote:
The use of glazes is regulated.


Crayons are regulated too, but that didn't stop the Chinese from using
lead pigment in crayons and selling them to the US with fake "ASTM"
safety markings on the box. That was about the same time we made them
"most favored nation" trading partners...

Best regards,
Bob




Christopher Green 28-08-2004 02:30 AM

Layne wrote in message . ..
On 26 Aug 2004 15:01:04 -0700, (Beecrofter) wrote:

Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and store.


I'm curious. Do *all* glazed pots have harmful substances in the
glaze? I mean we eat and drink from glazed cups and bowls?... Is there
any way of knowing if a glazed pot contains harmful substances?

Layne


The iffier the origin of the glazed ware, the iffier the glaze itself.
Anything from Mexico should be automatically suspect (traditional
glazes there leach much lead, and Mexican potters have been very
reluctant to change); commercial ware made in the US, Japan, or
northern Europe (particularly the UK) should be OK; everything else is
somewhere in between.

--
Chris Green

Dewitt 28-08-2004 03:31 AM

On 27 Aug 2004 07:31:44 -0700, (J. Del Col)
wrote:

Commercial glazed ceramic ware for table use is fired at high enough
temperature to burn out the lead and other metals. There are lead
test kits available if you are worried that your dinnerware or
flowerpots might be contaminated.


This is not at all true. Lead is volatile and not used in high fire
glazes, but it is used in low fire glazes and other metals such as
copper, cadmium, and cobalt are used in high fire glazes. These
metals, even lead, can be safely used if the glaze is properly
formulated and fired, but unfortunately this is often not the case.

deg

Layne 28-08-2004 04:01 AM

Thanks for all the additional info. I found test kits online and will
buy one to test this pot and the bathtub glaze.

Thanks,

Layne

On 27 Aug 2004 07:31:44 -0700, (J. Del Col)
wrote:

Layne wrote in message . ..
On 26 Aug 2004 15:01:04 -0700,
(Beecrofter) wrote:

Definately heavy metals in the glazing.
Lead or Cadmium which over time the human body seems to collect and store.


I'm curious. Do *all* glazed pots have harmful substances in the
glaze? I mean we eat and drink from glazed cups and bowls?... Is there
any way of knowing if a glazed pot contains harmful substances?


Commercial glazed ceramic ware for table use is fired at high enough
temperature to burn out the lead and other metals. There are lead
test kits available if you are worried that your dinnerware or
flowerpots might be contaminated.

About 50 years ago Fiesta Ware produced a red glazed ware that was
made with uranium salts in the glaze. It was radioactive, but it was
not really dangerous as long as you didn't use it frequently with
strongly acid foods.

Pieces of it are valuable items now.


J. Del Col




All times are GMT +1. The time now is 08:12 AM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
GardenBanter