I personally wouldn't use this sand for drainage in pots there are better
materials available,i.e gravel,polystyrene,crocks,pebbles etc these would
provide better drainage,sand would probably wash out of the pot leaving no
drainage!If you want to get rid of it mix it in with the soil in your
border.
kenty
"Nick Maclaren" wrote in message
...
In article ,
Andy Hunt wrote:
I have some builders' sand hanging around in my yard, and I was going to
use
it for drainage in some new pots I've bought today.

My dad however has advised me not to, he says that this sand contains
lots
of chemicals which won't do plants any good, because it is building sand.

Pour him another tankard of beer and sit him in the corner with the
other old fogies. He doesn't have a clue, I am afraid. Firstly,
builders' sand DOESN'T have chemicals added (and has any salt washed
out, to prevent trouble making mortar). Secondly, why on earth would
builders add chemicals (which cost money) if they could avoid it?
And, thirdly, they would have leached out.

The sand has been outside in the rain for at least 3 years - does anyone
know if my dad's correct about this, and if so, whether the rain would
have
washed the sand clean by now?

What it will have done is to wash the 'softness' out of it, leaving
it as unsuitable for mortar - I had a lot like that, and got caught.
However, the converse is that it will be OK for using to increase
drainage! It won't be as good as sharp sand, but will do. You can
also dry it and sieve it (yes, using a kitchen sieve) to make fine
sand suitable for filling in between paving blocks.

Even if it is full of chemicals, if I just use it for an inch-thick layer
of
drainage material at the bottom of each pot, would it be OK?

Yes. No problem. Just remember that it will be somewhat less free
draining than sharp sand, and will clog quite a lot faster, but
otherwise use it as sharp sand.

Now, this does assume that it was in a relatively shallow layer. If
it was in a high pile, then the softness probably WON'T have washed
out enough, at least at the bottom. You can test by mixing it up
with water in a bottle and seeing how fast it settles. If it all
settles very fast, it is washed; if not, it isn't.


Regards,
Nick Maclaren.