This question is applicable to a lot more than edible crops, but I'd
like to understand better about potting soil, whether for starting
plants or for container gardening. I've been using the cheap Lowes
potting soil for a few years. It looks to be largely organic stuff.
That is, it isn't just garden "dirt". OK, so that sounds right. Nice
consistency coming out of the bag. But I notice that this stuff
basically turns into mud after a while. That is, after a long and very
hot summer, when stuff is getting watered every other day to keep it
alive, you dig out a plant, and find that the plant has been trying to
grow in highly compacted and hugely soggy soil. This in a pot with
excellent drainage. Just to get the soil out of the pot, you can't do
it with fingers. You need a trowel to excavate it.

Now, this doesn't seem like the kind of stuff plants would like to be
growing in. I should have realized this was happening, because during
the summer, when I watered, it would sometime pool up in the top of
the pots, and take an hour to drain!! The way I was taught, soil
should absorb water, but be permeable enough to let it soak through.

I found a number of fat worms in it, so it can't be that bad, but ...

OK, my bad, using cheap potting soil. Butt head against wall, etc.

But I still have a few bags of it, and it seems to me that with
appropriate amendments, this stuff could still work. What should I
use? Coarse sand? Perlite? Vermiculite? Compost? Peat moss? Now, if
I'm going to add organic material to it, I'd like it to be stuff that
didn't eventually turn into the organic paste I seem to have ended up
with.

I don't know exactly what product you are describing when you say
"potting soil". There are pre-packaged soils out there for seed
starting that are light and fluffy; potting soils that are coarse and
have small chucks of wood in them; and then topsoil that is mainly
made out of decomposed organic stuff.

I am assuming that since you described it as getting clogged and
muddy when watered but has a nice consistency coming out of the bag,
then you must be talking about that cheap topsoil stuff that costs
$1.00 per 40 lb. bag.

You could use perlite to fluff it up some, but that might be
expensive to add enough to have a substantial effect. Sand is always
good to help with drainage, but it doesn't decompose or add any
nutrient value to it. Plus, it tends to carry downwards when you
water and settle into a layer at the bottom of the pot--which might
cause it to clog up the pot drainage holes later on.

What I normally do with my own potting plants is: 1) mix topsoil 1/2
and 1/2 with potting soil that has wood chunks in it (like the
moisture control Miracle Grow stuff), 2) add in some slow release
plant food, 3) shake it all up in a big trash bin in order to
thoroughly mix up the contents, and then 4) put it in the pot with the
plant.

If it is mixed right, you should be easily be able to transplant
your plant later on. Just don't water it for a couple of days and the
soil will shrink and stick together into one big cylinder. Afterwards,
turn the pot sideways and gently shake out the entire block--plant and
all. No need to damage the root system by trying to dig it out of the
soil.

Angello

On Sun, 15 Nov 2009 15:02:24 -0800 (PST), Dwight Lassiter
wrote:

This question is applicable to a lot more than edible crops, but I'd
like to understand better about potting soil, whether for starting
plants or for container gardening. I've been using the cheap Lowes
potting soil for a few years. It looks to be largely organic stuff.
That is, it isn't just garden "dirt". OK, so that sounds right. Nice
consistency coming out of the bag. But I notice that this stuff
basically turns into mud after a while. That is, after a long and very
hot summer, when stuff is getting watered every other day to keep it
alive, you dig out a plant, and find that the plant has been trying to
grow in highly compacted and hugely soggy soil. This in a pot with
excellent drainage. Just to get the soil out of the pot, you can't do
it with fingers. You need a trowel to excavate it.

Now, this doesn't seem like the kind of stuff plants would like to be
growing in. I should have realized this was happening, because during
the summer, when I watered, it would sometime pool up in the top of
the pots, and take an hour to drain!! The way I was taught, soil
should absorb water, but be permeable enough to let it soak through.

I found a number of fat worms in it, so it can't be that bad, but ...

OK, my bad, using cheap potting soil. Butt head against wall, etc.

But I still have a few bags of it, and it seems to me that with
appropriate amendments, this stuff could still work. What should I
use? Coarse sand? Perlite? Vermiculite? Compost? Peat moss? Now, if
I'm going to add organic material to it, I'd like it to be stuff that
didn't eventually turn into the organic paste I seem to have ended up
with.

Thanks, that makes sense. Actually, it wasn't "topsoil", but that $4/
bag mix. Maybe "planting mix" instead of "potting mix"? Again, it
appears mostly organic stuff because it's fluffy when it comes out of
the bag, and for some weeks/months after using it. Would be a good
trick to take plain topsoil and make it look that way. Good point
about sand migrating downward in the pot. Had not thought of that.
Also, the shrinkage, which I figured would be an inconvenience, does
indeed have an advantage in removal from the pot.

I'm thinking peat moss is good for fluffing it up as well, but does
that break down rapidly enough that you'd end up with the same organic
glue at the end of a season?

Peat moss is a pretty economical option (I think you can get a 2
cu.ft. brick of it for a couple of bucks) and will add fluffy-ness to
your slow-draining soil. It's also great at holding water--I think
it's able to retain about 20 times its weight in water. The down-side
it that it also adds a bit of acidity to the soil. Check the plant's
acidity tolerance levels before you do it. However, You can
counter-act the acidity by adding in some lime. I don't know about
how fast it breaks down though.

Another good option is to mix in composted manure. It'll add
nutrients while it decomposes and aereates the soil. The downside is
handling the odor if you are going to use it for indoor plants.

Angello

Thanks, that makes sense. Actually, it wasn't "topsoil", but that $4/
bag mix. Maybe "planting mix" instead of "potting mix"? Again, it
appears mostly organic stuff because it's fluffy when it comes out of
the bag, and for some weeks/months after using it. Would be a good
trick to take plain topsoil and make it look that way. Good point
about sand migrating downward in the pot. Had not thought of that.
Also, the shrinkage, which I figured would be an inconvenience, does
indeed have an advantage in removal from the pot.

I'm thinking peat moss is good for fluffing it up as well, but does
that break down rapidly enough that you'd end up with the same organic
glue at the end of a season?

Peat moss is a pretty economical option (I think you can get a 2
cu.ft. brick of it for a couple of bucks) and will add fluffy-ness to
your slow-draining soil. It's also great at holding water--I think
it's able to retain about 20 times its weight in water. The down-side
it that it also adds a bit of acidity to the soil. Check the plant's
acidity tolerance levels before you do it. However, You can
counter-act the acidity by adding in some lime. I don't know about
how fast it breaks down though.


Well, then I'm good to go with peat moss. I have irrigation water that
is mildly alkaline. Water table is limestone based, which accounts for
that alkalinity. So whatever my planting mix is made of, it eventually
gets somewhat alkaline. Adding acidity is just the ticket.

"Dwight Lassiter" wrote in message
...

Peat moss is a pretty economical option (I think you can get a 2
cu.ft. brick of it for a couple of bucks) and will add fluffy-ness to
your slow-draining soil. It's also great at holding water--I think
it's able to retain about 20 times its weight in water. The down-side
it that it also adds a bit of acidity to the soil. Check the plant's
acidity tolerance levels before you do it. However, You can
counter-act the acidity by adding in some lime. I don't know about
how fast it breaks down though.


Well, then I'm good to go with peat moss. I have irrigation water that
is mildly alkaline. Water table is limestone based, which accounts for
that alkalinity. So whatever my planting mix is made of, it eventually
gets somewhat alkaline. Adding acidity is just the ticket.



You can use tree bark ( preferably a fine grade ) to break up that soil
mix. Like Peat, its acidic, but not as much, and decomposes slowly.
10-12 $ a 1/2 yard here.

Some of the Coir and Coco chip products are also a good admendment choice
for small applications. The coir is ~ 3$ a brick ( makes approx 8 liters).

On Nov 15, 3:02*pm, Dwight Lassiter wrote:
This question is applicable to a lot more than edible crops, but I'd
like to understand better about potting soil, whether for starting
plants or for container gardening. I've been using the cheap Lowes
potting soil for a few years. It looks to be largely organic stuff.
That is, it isn't just garden "dirt". OK, so that sounds right. Nice
consistency coming out of the bag. But I notice that this stuff
basically turns into mud after a while. That is, after a long and very
hot summer, when stuff is getting watered every other day to keep it
alive, you dig out a plant, and find that the plant has been trying to
grow in highly compacted and hugely soggy soil. This in a pot with
excellent drainage. Just to get the soil out of the pot, you can't do
it with fingers. You need a trowel to excavate it.

Now, this doesn't seem like the kind of stuff plants would like to be
growing in. I should have realized this was happening, because during
the summer, when I watered, it would sometime pool up in the top of
the pots, and take an hour to drain!! The way I was taught, soil
should absorb water, but be permeable enough to let it soak through.

I found a number of fat worms in it, so it can't be that bad, but ...

OK, my bad, using cheap potting soil. Butt head against wall, etc.

But I still have a few bags of it, and it seems to me that with
appropriate amendments, this stuff could still work. What should I
use? Coarse sand? Perlite? Vermiculite? Compost? Peat moss? Now, if
I'm going to add organic material to it, I'd like it to be stuff that
didn't eventually turn into the organic paste I seem to have ended up
with.

I buy Perlite and Peat Moss to my black much also. The all organic
stuff deteriorate so quickly that a level 5 gallon pot will sink 4
inches in a season.
If I had a choice between the two, pick Perlite. The peat will
deteriorate also - the perlite will not.
Jim in So. Calif.

I buy Perlite and Peat Moss to my black much also. The all organic
stuff deteriorate so quickly that a level 5 gallon pot will sink 4
inches in a season.
If I had a choice between the two, pick Perlite. The peat will
deteriorate also - the perlite will not.
Jim in So. Calif.

Yes, that's what I assumed. Even the peat moss will eventually
decompose, though the stuff is fibrous enough that some structure may
remain. I just want some mix that will retain permeability for a few
seasons. Certainly true that perlite (or charcoal) should help with
that.

"Dwight Lassiter" wrote in message
...

I buy Perlite and Peat Moss to my black much also. The all organic
stuff deteriorate so quickly that a level 5 gallon pot will sink 4
inches in a season.
If I had a choice between the two, pick Perlite. The peat will
deteriorate also - the perlite will not.
Jim in So. Calif.

Yes, that's what I assumed. Even the peat moss will eventually
decompose, though the stuff is fibrous enough that some structure may
remain. I just want some mix that will retain permeability for a few
seasons. Certainly true that perlite (or charcoal) should help with
that.

Support structure aside, Perlite is pH neutral, charcoal pH will vary
depending, but mostly it will be alkaline.
Just be aware of what the specific addition will do to the soil chemistry
and factor in your hard water usage.

On Dec 2, 1:03*pm, "gunner" wrote:
"Dwight Lassiter" wrote in message

...



I buy Perlite and Peat Moss to my black much also. The all organic
stuff deteriorate so quickly that a level 5 gallon pot will sink 4
inches in a season.
If I had a choice between the two, pick Perlite. The peat will
deteriorate also - the perlite will not.
Jim in So. Calif.

Yes, that's what I assumed. Even the peat moss will eventually
decompose, though the stuff is fibrous enough that some structure may
remain. I just want some mix that will retain permeability for a few
seasons. Certainly true that perlite (or charcoal) should help with
that.

Support structure aside, Perlite is pH neutral, charcoal pH will vary
depending, *but mostly it will be alkaline.
Just be aware of what the specific addition will do to the soil chemistry
and factor in your hard water usage.

And in most of the Western US, the soil is very alkaline.
Living in So. Calif., I do not want to add anything to my garden soil
that is alkaline.
Most mixed supplements are ph. balanced to be neutral.
Jim in So. Calif.