Great, thank you. I don't have a lot of cactus knowledge so instantly feared the worst!

I agree with Rina it does look like natural corking. It's a nice looking cacti btw, it does look healthy.......at the moment.......but yes, what on earth is it planted in??? That looks like soggy, wet subsoil. Please tell us it's full ingredient list.

Few more questions, sorry! Have you had the cacti long and how often is it watered...with a teaspoon or a bucket for example, just so we have an idea of its current care. Does it get rained on? Full sun, shade? That soil is a worry...we will get it sorted one way or another! Ah just reread your post, it's kept indoors permanently so maybe it was placed outdoors, my initial thought, just for the photo shoot then?

Gill

Thanks for response.

Yes, I keep it inside at all times, apart when I'm watering so it can drain through (that's what I was doing today when I noticed the different colour under the surface... may also explain why it looks a bit soggy!). I've had it since March and watered for the first time at the end of April and have done so roughly every 4 weeks since. I've no idea what the soil mix is I'm afraid. I use something called cactus focus to feed that advises to mix 5ml with a litre of clean water, but doesn't indicate the size of cactus you would be using that on, so used half that amount the first few months as was concerned I would over feed!

Hazel? Hello again, thanks for getting back to us with the further info, sorry if we appear to be over questioning you but it's just to help in the long run :-) So we can assume it was bought with its current soil, you haven't repotted it?

Ok, whilst I grow a lot of plants, I don't grow one of these, that said,I'm reasonably aware of the likes of cacti in regard to their soils. As mentioned by Rina, a far wiser mixed succ and cacti grower than I, we are concerned about the soil.

If you decide to go with our suggestions, maybe hang on a short while and hopefully Rina will come back and confirm my suggestions.

It may mean that you will need to gather together some of the following ingredients, I'm sure Monsignor San Pedro would thank you in the long run and survive/thrive for even longer!

Most c/s growers would advocate a good brand of c/s mix with the least peat content the better, cut with a minimum of 50% perlite as a basic requirement for rapid and thorough drainage. I think your plant has the ability to grow large...how big is it at present from soil to tip?.....the larger, and taller the plant the less stable it can become. Lots of perlite makes a lightweight fluffy mix, plus it tends to turn green if it floats to the top. I would favour a mix of thirds such as a good brand already gritty C/s mix, perlite from B&Q or Wilko and something like B&Q horticultural/alpine grit, chicken grit or even aquarium gravel from Pets at Home or a similar type of gravel to give weight and stability. Please do not be persuaded to use anything with the word 'sand' in it, it's taboo! It's as bad as mentioning the play beginning with the letter 'M' to you!!!

I would ease off on the water as things are cooling down now, especially at night. If the above is what is advised by others, it would mean unpotting, rinsing the roots of all the old mix and checking thouroughly for any signs of rot, dead roots, mushy ones etc and also checking those bases of the columns closely. Any bad areas would need to be excised, dried, treated with sulphur powder or similar and repotted in the new mix. Don't be put off, it's not that bad a task, honest. Hang on for a while and see who else comes in.......

Gill

Looks like it is planted in unsifted pure red scoria/cinders. Or, is that only a top dressing?

Thanks again for all advice!

I haven't repotted it since buying, I wish I had asked more questions at the time! I did read that it likes to be quite snug in its pot, so thought it wouldn't be an issue until some growth. To be honest, I don't think it really has grown. It's about 15 inches to its highest point. I have read they can grow quite a bit through the feeding months, but again, put it's lack of growth down to not being in a hot climate.

After a bit of a poke about - the soil does look the same all the way down, with maybe something gravely too as there are bigger bits!

Il hold on to see if anyone has more advice on soil type/mix. Will definitely repot if the best thing to do... although I'm amazed people manage. It's quite a heavy beast!

Possibly a silly question... but is it likely the plant is all connected underneath or is it separate limbs...

Thanks again, hazel

I had the same question because of the way they are all snuggled so close to each other. Anyway, it is a nice looking clump.

That's unsifted red scoria. The cactus might be OK in that. Though the top might seem completely dry while deeper it is still moist. Usually cacti and succulent growers don't use pure red scoria but mix it in with some other ingredients. I've thought about trying some plants in pure scoria but I have really fine left over bits. It is almost like sand. I'd need to go to a landscape supply business to get a bag that has a range of piece sizes.

Polypp, thanks for the ID of the mix. I've never seen that ingredient over here before, and I've looked into many a plant pot in my lifetime! It does look as though there's a lot of small material in there, as you say, it's unsifted. I'm stil very sceptical about it.

Hazel, does the water drain out almost as soon as it's being put in or does it take an age to drain out? Does there seem to be a lot of it retained by the mix, or does the majority appear to drain? Just trying to ascertain if this scoria stuff is holding onto more water than the plant needs or can use as that could well lead to root issues that can't be seen at the moment, but could show up in a bad way later on.

Gill

Scoria is denser than pumice, so I wonder about it's water retention. I have few larger chunks (about 1-2") and tried to break them - found it very hard to do.

Never had chance to use it for plants - but maybe it would be better mixed with perlite?...

ps: Just read previous posts; Gill - you are giving me too much credit! I have only handful of cacti, but prefer them in most gritty mix. I left one in original soil + little extra perlite mixed in while away, and it was the only plant that didn't like the rain - all other succulents survived without problems...

I think it drains out pretty quickly. I do tend to pick a sunny day to feed so the top never looks damp for long and there is a definite flow onto the ledge/down the wall. The top soil maybe looks red for a day after then goes bk to...