John Innes compost replacements

For the discussion of topics related to the conservation, cultivation, propagation and exhibition of cacti & other succulents.
Forum rules
For the discussion of topics related to the conservation, cultivation, propagation, exhibition & science of cacti & other succulents only.

Please respect all forum members opinions and if you can't make a civil reply, don't reply!
Davey246
Registered Guest
Posts: 417
https://www.behance.net/kuchnie-warszawa
Joined: 19 Oct 2021
Branch: LEICESTER
Country: United Kingdom
Location: Leicester

Re: John Innes compost replacements

Post by Davey246 »

Herts Mike wrote: Wed May 18, 2022 4:56 pm I used 100% moler clay for a season on my Stapeliads and the result was very good but I found the watering difficult and cumbersome as the water goes straight through and I couldn’t find a suitable tray to stand them in. What do you do Nick?
Stapeliads are more awkward than cacti, as a gross generalisation. I use something like 1 part JI plus 4 parts mixed aggregate - perlite, gritty sand and coarse grit, all by volume.
It works OK for me, but bear in mind that most stapeliads are more than happy to massively overflow a pot, so watering the small amount of potting mix to near staruration represents rather little total water for the plant and lasts it quite a while.
For plants with awkward reputations, I use the pedio' trick - use a moderately moisture-retentive compost mix but use large stones in the pot to reduce the volume of the compost mix while giving the plant lots of root room and reducing evaporation rate.

Depending on age, people may or not remember that building aggregates used to be sold in the UK by volume - you bought a (cubic) yard of soft sand (or whatever). It was sold by volume for very good reason - sands will hold 25-50% of their dry weight, of water - a yard of sand could weigh between a ton and a ton and a half at the extremes. In a potting mix including lots of fines, even if 100% mineral, this is VERY significant, IMO. (Oooooops, slipped in an opinion there................................that will never do!)
User avatar
Diane
BCSS Member
Posts: 5574
Joined: 15 Jun 2007
Branch: None
Country: UK
Role within the BCSS: Member

Re: John Innes compost replacements

Post by Diane »

“Point me in the direction of opinion rather than experience over 40-50 years, that I have posted. I am very interested to learn from you.”

I wouldn’t even attempt to teach you anything, Davey, as you already know it all.
Diane - member of Kingston branch

Growing cacti - balm to the soul!
User avatar
Paul D
BCSS Trustee
Posts: 1144
Joined: 21 May 2009
Branch: GRAMPIAN (N.E.Scotland)
Country: UK
Role within the BCSS: Trustee
Location: Collieston, Aberdeenshire
Contact:

Re: John Innes compost replacements

Post by Paul D »

I've been using 50% pumice and 50% lava rock, feeding with every water, for all my Sulcos for the last 5 years or so, and getting good results. But I find that Aylostera and Rebutia do better with an organic component. Maybe something to do with water retention.
Sylvagrow Ericaceous is indeed described as compost, but appears to be entirely composted bark and coir. I suspect the sciarid flies are going to love it. However if used just to replace the peat component in John Innes (i.e. 7 parts loam to 3 parts Sylvagrow to 2 parts sand) then it might be fine. My usual cactus mix is only about a third JI in any case.
Paul in North-east Scotland (Grampian Branch BCSS)
National Collection Rebutia, Aylostera & Weingartia (inc. Sulcorebutia). Also growing a mixture including Ferocactus, Gymnocalycium, Lobivia, Mammillaria, Lithops, Gasteria, Haworthia.
http://www.rebutia.org.uk
Herts Mike
BCSS Member
Posts: 4303
Joined: 20 Sep 2007
Branch: LEA VALLEY
Country: Uk

Re: John Innes compost replacements

Post by Herts Mike »

I have experience of over 50 years. Any good?
Davey246
Registered Guest
Posts: 417
Joined: 19 Oct 2021
Branch: LEICESTER
Country: United Kingdom
Location: Leicester

Re: John Innes compost replacements

Post by Davey246 »

Diane wrote: Wed May 18, 2022 5:18 pm I wouldn’t even attempt to teach you anything, Davey, as you already know it all.
Thank you very much, I am most grateful. Or maybe you couldn't find anything?
Davey246
Registered Guest
Posts: 417
Joined: 19 Oct 2021
Branch: LEICESTER
Country: United Kingdom
Location: Leicester

Re: John Innes compost replacements

Post by Davey246 »

Paul D wrote: Wed May 18, 2022 5:21 pmSylvagrow Ericaceous is indeed described as compost, but appears to be entirely composted bark and coir.
Not on the Sylvagrow webpage that I read - neither compost nor composted mentioned. If they claim otherwise elsewhere, we shall never know.

If it is down to water retention, try adding realtively fine aggreagate to your all-mineral mix.

LONG ago, I did some simple measurements, out of curiosity, using my cactus mix. Bone dry was achieved by drying in an oven. To take the mix to damp enough for the mix to hold together when squeezed in the hand, took roughly 20% by weight of water - a 2.5 inch pots held 20ml of water and 108g of potting mix. The mix was saturated - wet to the extent that none actually drained from the pot - at around 50% by weight of water - the same pot held 44ml of water (and 108g of potting mix).

Nerdy, but very simple to do. And I wrote it down, around 30 years ago. I actually measured everything from bone dry to flooded, in 5 steps.
Last edited by Davey246 on Wed May 18, 2022 5:40 pm, edited 1 time in total.
User avatar
Paul D
BCSS Trustee
Posts: 1144
Joined: 21 May 2009
Branch: GRAMPIAN (N.E.Scotland)
Country: UK
Role within the BCSS: Trustee
Location: Collieston, Aberdeenshire
Contact:

Re: John Innes compost replacements

Post by Paul D »

Davey246 wrote: Wed May 18, 2022 5:32 pm
Paul D wrote: Wed May 18, 2022 5:21 pmSylvagrow Ericaceous is indeed described as compost, but appears to be entirely composted bark and coir.
Not on the Sylvagrow webpage that I read - neither compost nor composted mentioned. If they claim otherwise elsewhere, we shall never know.
Here you go:
https://melcourt.co.uk/products/sylvagrow-ericaceous/
It says compost on the packaging.
Paul in North-east Scotland (Grampian Branch BCSS)
National Collection Rebutia, Aylostera & Weingartia (inc. Sulcorebutia). Also growing a mixture including Ferocactus, Gymnocalycium, Lobivia, Mammillaria, Lithops, Gasteria, Haworthia.
http://www.rebutia.org.uk
User avatar
Tony R
Moderator
Posts: 4011
Joined: 20 Apr 2009
Branch: BROMLEY
Country: UK
Role within the BCSS: Member
Location: Hartley, LONGFIELD, Kent

Re: John Innes compost replacements

Post by Tony R »

Indeed, Paul, and twice in the text on the same page:

This professional-quality, 100% peat-free ericaceous compost ........
and
Superb quality, 100% peat-free compost as used by professionals

(tu)
Tony Roberts
Treasurer, Haworthia Society
Chairman, Tephrocactus Study Group
Moderator, BCSS Forum
Kent
(Gasteria, Mammillaria, small Opuntia, Cleistocactus and Sempervivum are my current special interests)
Davey246
Registered Guest
Posts: 417
Joined: 19 Oct 2021
Branch: LEICESTER
Country: United Kingdom
Location: Leicester

Re: John Innes compost replacements

Post by Davey246 »

Paul D wrote: Wed May 18, 2022 5:33 pm
Davey246 wrote: Wed May 18, 2022 5:32 pm
Paul D wrote: Wed May 18, 2022 5:21 pmSylvagrow Ericaceous is indeed described as compost, but appears to be entirely composted bark and coir.
Not on the Sylvagrow webpage that I read - neither compost nor composted mentioned. If they claim otherwise elsewhere, we shall never know.
Here you go:
https://melcourt.co.uk/products/sylvagrow-ericaceous/
It says compost on the packaging.
That does mention compost, but not composted. I would bet quite a bit (and I do not bet, at all, in any normal circumstances), that the bark and coir are not composted. Simply becaue they compost down to amorphous sludge - I have seen it here countless times - the mix would have no structure if they were composted - if you have ever seen sedge (as opposed to moss) peat, it would be very similar, probably less structured.

(Sedge peat used to be sold, primarily, as a lawn treatment because it was so fine/dusty, so that it brushed into the lawn easily.)

If anyone wants structured composted potting material, make leafmould. Depending on the species of leaf it will take 2 years and more - hopeless for commercial use. YES, I do make leafmould, from beech.

FYI - composting generally happens via a lot of bacterial action - fast and hot (my compost heap can get too hot to thrust your arm into). Leafmould relies almsot entirely on fungal degredation - slow and cold.
Nick_G
BCSS Member
Posts: 750
Joined: 12 Apr 2013
Branch: None
Country: Shetland

Re: John Innes compost replacements

Post by Nick_G »

Herts Mike wrote: Wed May 18, 2022 4:56 pm
Nick_G wrote: Wed May 18, 2022 4:16 pm I'm using Melcourt peat free compost to grow Chinese broccoli in tubs and the growth has been excellent. I'll report back as to how much the stuff has broken down at the end of the summer. It's nice stuff to use.

I use 100% moler clay for my cacti.
I used 100% moler clay for a season on my Stapeliads and the result was very good but I found the watering difficult and cumbersome as the water goes straight through and I couldn’t find a suitable tray to stand them in. What do you do Nick?
I just make sure I soak all of the top of the pot with a watering can with a rose. For taller plants I don't use the rose.
BCSS no.33806

Turbinicarpus, Lophophora, Ariocarpus, Lobivia and Gymnocalycium
Post Reply