Size of grit.

[MalcolmP2]

Searching the forum and googling I see lots of ref to coarse grit and to 3mm grit (or sometimes 4mm).
Does this mean only coarse with no fine in it ? ie. not "3mm to dust".

I am thinking that there is already a lot of fine in the JI loam based composts and that it would be best to sieve out the finest dust from the added grit, using only the approx. 1 to 3mm portion.

Does that make sense ? or just a lot of extra effort !

[Jim_Mercer]

Ideally no dust as you are trying to add grit not sand ie just large particles. If you buy washed horticultural grit there should be no dust but if you use other products there may be some. I now use jondo flint grit in either chick or hen size which seems to have fairly consistent particle sizes and I don't bother washing it - same with the moler clay cat litter which does have some dust

[Terry S.]

Yes, you do not want grit with fines in it. I buy bags of "horticultural coarse grit" and the particle size is around 2 - 6mm with an average of about 4mm. I have had it under the Arthur Bowers, Silvaperl and Westland labels.

[MalcolmP2]

yes this is 'other products' type - Cornish grit that I have quite a lot of for various uses. however it is about 1/3rd <1.4mm to dust, so not good for cactus mixing then

I am out of Washed Horticultural at the mo, so it looks like a trip to the garden shop is indicated.
I always seem to come back with more things than I intended though

Thanks

Added later :-
Otherwise a lot of work with my heirloom device !

0377.jpg (35.26 KiB) Viewed 2969 times

[el48tel]

There are some decent "2 for ££" or "three for two" offers around (at Christmas some super ones). I've justused up the last of my "looks like crushed granite tombstones or worktops" bags.

[Apicra]

Hi MalcolmP2,

Please can you say exactly where you bought that "Cornish grit"? The coarser ones look like just what I am looking for and I'm in Somerset on Wed speaking at Taunton Branch about CATs. I don't mind a detour and such grit is very difficult to find in the London area.

Best wishes,
Derek Tribble

[ralphrmartin]

I buy granite grit from my local quarry, in a size "up to 10mm". It costs £30 for a builder's bag, or £40 delivered. I thought at first it would be too coarse, but it actually works quite well. I sieve out stuff smaller than about 2mm (there's not much of it) and that goes into my seed compost.

[MalcolmP2]

Please can you say exactly where you bought that "Cornish grit"? The coarser ones look like just what I am looking

Hi Derek,
It was at
Cleeve Nursery and Garden Centre
Main Road, Cleeve, Bristol, BS49 4PW
https://www.cleevenursery.co.uk

BUT now the caveat :-
it was several years ago that I bought it (when I was into breeding discus and other S.A. cichlids) and was then sold in clear plastic sacks with lettering on. I understood the owner/proprietor sourced it himself, as a waste from the kaolin workings down there.
I was there again a couple of weeks ago and it is now being sold in plain black plastic sacks with no lettering (at least not that I noticed but I wasnt looking for any more at the time !)
So, I cannot swear that it is exactly the same stuff, it may not be as coarse now but I only glanced that way. They have a pot of it alongside so you will be able to inspect it ok.

Another possibility, just down the road from there is
Cadbury Garden Centre
Congresbury, Bristol BS49 5AA
https://www.bluediamond.gg/garden-centr ... den-centre
they have Melcourt Horticultural Potting Grit
(now owned by Blue Diamond group who have some branches over your way, maybe worth an ask)

Quote
" Ideal for cacti, succulents and alpines:-
as a decorative top dressing
for incorporating into compost mixes to improve drainage
Helps improve drainage when dug into heavy soil
1-4 mm nominal particle size
Washed "
/Quote.

I have not found a techspec on the Melcourt site for it but from the pic on the sack it looks similar stuff. Cadbury did not have one open so I dunno.

Sorry I cannot be more up to date for you.

hth,
Malcolm.
EDIT : hmmm that is odd, suddenly the topic has become solved !!

[habanerocat]

I was in ELK last year to rebuild my collection. I bought a lot of Sulcos from a French nursery. Good plants, but unfortunately the owner told me they don't have a website and don't sell online. Anybody know who they might be?

Anyway all the Sulcos were growing in a limestone/quartz type of grit that they sourced locally. Like a slag. And very well they were growing too.

[MalcolmP2]

Good morning all.
How can I remove the "solved" marker ?