I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

In article .com,
says...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome


I almost always mix around 20% of sharp sand with multi-purpose compost,
the plants / cuttings / seeds / seedlings all seem to fare better than
with just plain compost. It doesn't tend to shrink so badly and like you
say it's water retention properties seem a bit more "balanced" allowing
excess to water to drain through but holding moisture for longer.

The most noticeable effect is with cuttings, they much prefer some sharp
sand mixed in.
--
David in Normandy

David in Normandy wrote:
In article .com,
says...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome


I almost always mix around 20% of sharp sand with multi-purpose compost,
the plants / cuttings / seeds / seedlings all seem to fare better than
with just plain compost. It doesn't tend to shrink so badly and like you
say it's water retention properties seem a bit more "balanced" allowing
excess to water to drain through but holding moisture for longer.

The most noticeable effect is with cuttings, they much prefer some sharp
sand mixed in.

I've wondered about soft sand too. It should work in the same way but I
suppose wouldn't break down the compost as easily when you mix it. Nice
fine structure though.

The only concern I have with sand is making the texture attractive to
ants, which have killed off a good few of my window boxes over the years.

In article ,
Stuart Noble writes:
|
| I've wondered about soft sand too. It should work in the same way but I
| suppose wouldn't break down the compost as easily when you mix it. Nice
| fine structure though.

Not at all, actually.


Regards,
Nick Maclaren.

In article ,
says...
David in Normandy wrote:
In article .com,
says...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome


I almost always mix around 20% of sharp sand with multi-purpose compost,
the plants / cuttings / seeds / seedlings all seem to fare better than
with just plain compost. It doesn't tend to shrink so badly and like you
say it's water retention properties seem a bit more "balanced" allowing
excess to water to drain through but holding moisture for longer.

The most noticeable effect is with cuttings, they much prefer some sharp
sand mixed in.

I've wondered about soft sand too. It should work in the same way but I
suppose wouldn't break down the compost as easily when you mix it. Nice
fine structure though.

The only concern I have with sand is making the texture attractive to
ants, which have killed off a good few of my window boxes over the years.

Personally i would avoid soft sand/builders sand as this often has a
percentage of clay and its action in compost is not what you would expect
and you will get a lot of rotting problems it can also contain lime
(which sharp sand and horticultural grit should not)
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea

wrote:

I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

For years now I have made my own compost based on a 3:1 peat:sharp sand
mix with latterly Chempak potting base fertiliser mix. Seedlings do very
well and I use it for tubs and pots as well - and there is no problem
with ants although the infest the garden.

Malcolm

"Charlie Pridham" wrote in message

Personally i would avoid soft sand/builders sand as this often has a
percentage of clay and its action in compost is not what you would expect
and you will get a lot of rotting problems it can also contain lime
(which sharp sand and horticultural grit should not)

That's interesting, I've never heard an explanation before, thank you.

Mary

" wrote in
message oups.com...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

It matters not what the actual % of water is in that mix. Of more importance
is the % of air that is in the root region. Sharp sand
/vermiculite/Perlite/wood chips will give a better aeration due to particle
size.
Your original calculations also need to compare water retention over a fixed
time and relate to w/w and take account of bulk density.

Malcolm Race wrote:
wrote:

I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

For years now I have made my own compost based on a 3:1 peat:sharp sand
mix with latterly Chempak potting base fertiliser mix. Seedlings do very
well and I use it for tubs and pots as well - and there is no problem
with ants although the infest the garden.

Malcolm

Do you mean real peat? I don't know what the cheap compost you buy in
garden centres is made from but I doubt if it contains much in the way
of nutrients. I'll look into the fertiliser question. At the moment I
just water everything with a very dilute Phostrogen.

Rupert (W.Yorkshire) wrote:
" wrote in
message oups.com...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

It matters not what the actual % of water is in that mix. Of more importance
is the % of air that is in the root region. Sharp sand
/vermiculite/Perlite/wood chips will give a better aeration due to particle
size.
Your original calculations also need to compare water retention over a fixed
time and relate to w/w and take account of bulk density.



Hmm. The tests I did were pretty basic, comparing how much water had
drained out of the 2 samples after 24 hours. Seems to me that sand is
able to hold water in its structure without absorbing it, rather like a
J-Cloth.
Now that I've finally found a local source for perlite/vermiculite I
might give them a try but they don't seem to offer any advantages over
sand. My garden is a bit of a wind tunnel so the extra weight is a bonus
for the pots and troughs.
I hadn't thought about the aeration issue. You can tell I'm not much of
a gardener :-)

"Stuart Noble" wrote in message
...
Rupert (W.Yorkshire) wrote:
" wrote in
message oups.com...
I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

It matters not what the actual % of water is in that mix. Of more
importance is the % of air that is in the root region. Sharp sand
/vermiculite/Perlite/wood chips will give a better aeration due to
particle size.
Your original calculations also need to compare water retention over a
fixed time and relate to w/w and take account of bulk density.

Hmm. The tests I did were pretty basic, comparing how much water had
drained out of the 2 samples after 24 hours. Seems to me that sand is able
to hold water in its structure without absorbing it, rather like a
J-Cloth.
Now that I've finally found a local source for perlite/vermiculite I might
give them a try but they don't seem to offer any advantages over sand. My
garden is a bit of a wind tunnel so the extra weight is a bonus for the
pots and troughs.
I hadn't thought about the aeration issue. You can tell I'm not much of a
gardener :-)

Stuart, The professionals have been arguing for decades about the various
merits of potting media and they still do not agree :-)

Stuart Noble wrote:
Malcolm Race wrote:

wrote:

I wonder if anyone has an opinion about the water retention of sand
when mixed with the general purpose compost you buy in a garden
centre. My experience is that, added at 25%, the mix actually retains
more water than the compost alone. Maybe this is partly due to the
sand breaking down the compost into fine and evenly distributed
particles or something.
Any thoughts welcome

For years now I have made my own compost based on a 3:1 peat:sharp
sand mix with latterly Chempak potting base fertiliser mix. Seedlings
do very well and I use it for tubs and pots as well - and there is no
problem with ants although the infest the garden.

Malcolm


Do you mean real peat? I don't know what the cheap compost you buy in
garden centres is made from but I doubt if it contains much in the way
of nutrients. I'll look into the fertiliser question. At the moment I
just water everything with a very dilute Phostrogen.
Yes, I know it isn't particularly PC but the amount I get through in a
year is small

Malcolm