Multipurpose Compost question

[Rob H]

Is peat free compost neutral and ok for alkaline loving plants, and
compost with peat is acidic.

I ask because I bought some MP compost , it didn't say it was peat free,
and I found it was acidic.
Thanks

[Rob H]

On 14/09/2022 21:32, Chris Hogg wrote:

> Composts with peat can be acidic or alkaline, depending on how much
> lime the manufacturer has added. For example, John Innes composts all
> contain some peat. Nos. 1, 2 & 3 are all alkaline, but John Innes
> Ericaceous is acidic, because it's had no lime added.
>
> I suspect peat-free composts are similar, but whether they add lime,
> and whether the lime-free peat-free compost, equivalent to JI
> Ericaceous, is naturally acidic, I don't know.
>
> I would have expected multi-purpose compost to be alkaline - I think
> most are - but did it say on the bag it was suitable for ericaceous
> plants such as rhododendrons?
>
> OOI How did you test for acidity?
>

Thanks, but no it didn't say what it was on the bag, and I used a pH
meter to test it.The said compost was in a yellow and green bag ,which I
can't recall any name on it now.

I also bought a bag of westlands all purpose compost which did contain
peat, and that was also acidic. But again, it didn't say if it was
acidic or neutral.

[Martin Brown]

On 14/09/2022 20:10, Rob H wrote:
> Is peat free compost neutral and ok for alkaline loving plants, and
> compost with peat is acidic.

The most recent peat free compost I bought was complete rubbish (*)
matched only by the bag of so called John Innes No2 which looked more
like water logged anaerobic puddled clay than anything else.

It was more suited to pottery making than gardening.

(*) My own home made leaf mould was way better as a growing medium.

> I ask because I bought some MP compost , it didn't say it was peat free,
> and I found it was acidic.

Most composts are slightly acidic - it comes from the organic content.

If you really are growing alkaline loving plants then you will need to
add crushed limestone to the mix. There are some plants that do require
it but they are comparatively rare.

OTOH there are plenty of lime haters that will turn up their toes if the
pH is too high since it prevents uptake of iron and making chlorophyll.

--
Regards,
Martin Brown

[Jeff Layman]

On 15/09/2022 08:47, Martin Brown wrote:
> On 14/09/2022 20:10, Rob H wrote:
>> Is peat free compost neutral and ok for alkaline loving plants, and
>> compost with peat is acidic.
>
> The most recent peat free compost I bought was complete rubbish (*)
> matched only by the bag of so called John Innes No2 which looked more
> like water logged anaerobic puddled clay than anything else.

Having been informed in this NG of the Melcourt "SylvaGrow" range of
composts I now don't use anything else. They aren't cheap, but the
quality is there. I get mine at my relatively local Blue Diamond garden
centre.

> It was more suited to pottery making than gardening.
>
> (*) My own home made leaf mould was way better as a growing medium.
>
>> I ask because I bought some MP compost , it didn't say it was peat free,
>> and I found it was acidic.
>
> Most composts are slightly acidic - it comes from the organic content.
>
> If you really are growing alkaline loving plants then you will need to
> add crushed limestone to the mix. There are some plants that do require
> it but they are comparatively rare.
>
> OTOH there are plenty of lime haters that will turn up their toes if the
> pH is too high since it prevents uptake of iron and making chlorophyll.

I use SylvaGrow Ericaceous for everything. I used to "dilute" it with
peat for some proteaceous plants as they don't like too much phosphate,
but peat has become almost unobtainable. I'm now using another source of
"filler", although it probably has more nutrients than peat:
<https://www.macpennys.co.uk/brackenCompost.php>

--

Jeff

[Martin Brown]

If you have the space I recommend making your own leaf mould.

I find my official green waste bin perfect for the task after it
mysteriously developed a few 1cm drainage holes in the bottom. Fill with
leaves in season and then leave for a year watering every now and then.
Then decant into black bins for another year. It shrinks down pretty
quick. One green bin goes into about 1.5 black bins semi rotted.

It makes a really fine ericaceous type compost in the second year if you
are lucky and third year if you are not. Speed of its disintegration is
mediated by how many worms migrate into it.

I already compost way more than they allow into the green bin stream. My
compost heaps run hot and produce pretty good compost but not quite good
enough to use for seed raising.

--
Regards,
Martin Brown

[Rob H]

On 15/09/2022 08:59, Jeff Layman wrote:

Thanks, I'll have a look for that, but can't say I've seen it anywhere
locally.

I remember years ago, you could buy the green and yellow bags of
multipurpose compost for alkaline plants and it was ok. Now , well ,
it's a bit different as you have to check what it is.

[Charlie Pridham]

On 15/09/2022 08:59, Jeff Layman wrote:

I was using Melcourt until the start of this year when we started
getting problems then a few months ago received this from them

"We would like to draw your attention to a special clause in our Terms
and Conditions of Sale which
deals with Melcourt Sylvamix in particular.
In the last couple of years a particular fungus has appeared in a very
small amount of Sylvamix. We
know of around 12 cases and of these, three have found a problem that
has affected plant growth
enough to have caused a claim.
The fungus is called Melanoleuca verrucipes and shows as a white
toadstool with pale brown
blotches on the stem, common name Warty Cavalier. It does not attack
plants but the mycelium can
create water repellent areas in the growing medium and then start to
change the nature of the
compost such that root growth is impeded. This takes several months and
correspondingly, the
fungus has not been reported in short term crops. Some plants have been
unaffected by its
presence, particularly those in large pots.
For 19 years we have sold Sylvamix very successfully with no significant
issues and no insurance
claims before the three for Melanoleuca in the last 12 months.
We don’t yet know if the fungus comes in with the Sylvamix or if the
spores ‘find’ it once on the
nursery but we have engaged an academic mycologist who is very familiar
with the UK ornamentals
industry to help us find out more.
Despite a very small volume of our production being affected (less than
0.5% in one year and fewer
than 1% of Sylvamix users) our insurers have declined to reinsure any
aspect of Sylvamix. Therefore,
we are having to insert a new, special clause into our Term and
Conditions of Sale. The new clause
limits our liability to the price paid by the grower for the Sylvamix
plus up to another 50% of that as
a measure of commitment on our part, on an ex gratia basis. Our
distributor, through whom you buy
Sylvamix, will be amending their Terms and Conditions accordingly.
This course of action and the new terms have been done with the full
guidance and approval of our
commercial lawyer and we are hereby carrying out what is called ‘full
disclosure’, without which it is
not legal to limit product liability. Any orders placed for Sylvamix by
your nursery from now on will
be deemed to be in the light of this new information and therefore
subject to the new terms.
Melcourt Industries Ltd | Boldridge Brake | Long Newnton | Tetbury |
Gloucestershire | GL8 8RT"

Now using Levingtons peat free (mixed with soil) which so far is working
well

--
Charlie Pridham
Gardening in Cornwall
www.roselandhouse.co.uk

[Rob H]

I've just bough a 60Litre bag of Jamesons peat free compost and they
state that the pH is between 6.0 and 8.0. It wasn't cheap, but at least
I know what I am getting.

[Martin Brown]

Why didn't you just buy some limestone chips or even smash up some old
mortar if you wanted to adjust potting soil pH to alkaline?

What are you growing that is so specific to a limestone environment?

I'm usually trying to go the other way for mostly lime haters.

It would be interesting to compare brands that people have recently (ie
in the current season found to be OK). One snag with black polythene is
that you really are buying a pig in a poke. Some of the commercial stuff
I bought this year was significantly worse than my own home made compost :(


--
Regards,
Martin Brown

[Rob H]

Well for a long time I have had a mix of both neutral compost and
ericaceous compost. The said neutral compost came in those yellow and
green bags and said multipurpose compost.
The reason I want a neutral compost like I used to be able to buy, is
because I have a range of different plants which like either one or the
other type of compost. Not all my potted plants like ericaceous compost.

My front garden soil is neutral, while my back garden soil is acidic.
When I plant different plants in either front or back garden, I use
compost in the hole mixed up with grit or similar.

I will get some limestone chips for another bag of acidic compost so
that I have 2 bags of neutral compost .

[Jeff Layman]

On 16/09/2022 11:11, Charlie Pridham wrote:

But would Levingtons do what Melcourt have done and let you know there
appears to be a problem? It seems to me Melcourt has identified a
possible problem and are trying to find a solution for it. The T&C
change is not unexpected; their explanation makes sense to me. (The T&C
disclaimer can be found in section 9 here:
<https://fargro.co.uk/policy-documents/terms-and-conditions>)

I am not sure what the difference is between the Sylvamix and SylvaGrow
ranges as they appear to overlap in places. Is the Sylvamix range only
for trade as it is usually bought in large quantities? I bought a couple
of bags of SylvaGrow Ericaceous earlier this week, so it will be
interesting to see if any fungus appears when I have potted up plants in it.

Anyway, according to Table 1 in the paper at
<https://www.mdpi.com/1999-4907/9/12/773/pdf>, Melanoleuca verrucipes is
not a pathogen, and it is not mentioned as a pathogen in
<http://davidmoore.org.uk/21st_Century_Guidebook_to_Fungi_PLATINUM/REPRINT_collection/Matheny_etal_clades-of-Agaricales.pdf>.

--

Jeff

[Rob H]

I cancelled the Jamesons compost order and ordered a 5L bag of Melcourt
Slvagrow.

[Charlie Pridham]

On 16/09/2022 19:50, Jeff Layman wrote:

No it doesn't seem to directly kill plants its just that it makes the
compost very difficult to water

(I have never worked out the difference in the various ranges that
Melcourt offer either!)

[Jeff Layman]

Does it make no difference if you use a wetting agent? It seems to me
that many modern composts - most certainly those with lots of peat - are
always difficult to wet once they've been allowed to become completely
dry. I've not let SylvaGrow become completely dry, so don't know if it's
difficult to wet in that condition.

> (I have never worked out the difference in the various ranges that
> Melcourt offer either!)

I doubt that more than half-a-dozen varieties are required, really, and
even that might be excessive.

--

Jeff