Ideal Soil/Substrate Mix

[HaoBao]

Thank you for that Ralph, I just read through it and as always with me I'll have to do it again to try and get it into my head

This is a link to the article if anyone else wants a look:
https://www.jstor.org/stable/42788945?s ... b_contents

As the article is from 1949 I would be interested to hear what Buxbaum would think of using LED tube lights for plants, but there's no way of knowing. Buxbaum says, what some members here also said, that peoples conditions will be different. Buxbaum says because of different conditions it's 'fundamentally wrong to try to give general instructions'. I think this is getting repeated in this thread but without considering that growing indoors with lights offers a much greater level of consistency between locations that would otherwise be true if the plants were outside. I don't think Buxbaum would have considered the use of artificial light, they never mention it in the article.

From what I can gather in the article it's suggested 3 factors that are the most important.

1) Soil Conditions (physical, chemical and space)

This is what I'm trying to experiment with.

2) Light and temperature

I can vary the light indoors, for example the haworthia have two lights above them compared to having three lights for the rest. The temperature I can't really change as it's indoors so just standard room temperature 16C-20C. The member that grows the lovely echeveria and pachyphytum has them in her garage where it's cooler and they look much better. She did say because it's cooler she uses a quicker drying mix than akadama.

3) Atmospheric and soil moisture content.

This one I suppose comes from how quickly the soil stays wet, something else that the test should help me find out.

Buxbaum says when growing in Europe humus is added to the soil so that the fine clay particles don't compact and rob the roots of air and minerals in drought areas can be surprisingly high although low in nitrogen.

I did hear that if adding Lava Rock to the soil the plants wouldn't need much fertiliser at all. Some other people suggested that pumice can add beneficial minerals too. I have no idea but I guess it could be true.

Buxbaum mentions potting similar plants together in seed trays but only if they come from a similar area or at least have the same requirements and that the results are surprisingly good.

I did think about doing this with my haworthia, thinking that they are not too sensitive to water and it might give the roots more room. I never got around to it though it would probably give me a bit more room on the shelves too. I don't know what other plants could be grouped together, either in the same tray or treated in a similar way. That's one of the main reasons I started this thread. I think I need to find out what everyone refers to as tricky plants too, at least if it's just the ones in my collection for now.

Buxbaum mentions plants from Southern California being intolerant of stagnant moisture compared to ones from Chile.

Would the Southern California are Buxbaum refers to include echeveria and astrophytum? They are the ones I'm still having most trouble with.

Pattock, yes a more suitably named thread might help, me saying 'ideal substrate' might make it sound like I'm looking for that 'One answer' which isn't really what I'm after and could also make it more focused on indoor growing under lights.

Phil_SK, I did try and go back and try to sift all the unanswered questions that were missed, repeating the ones that were missed might seem like it was going in circles but I'd still like to find out the answers to some of them. I said the next step for me was to try different soils after getting some advice for the echeveria/pachyphytum needing a quicker drying mix and less fertiliser so that's what thetest was for.

It's just a bit disheartening to be repeatedly told the ones I'm having trouble with are easy ones, or use whatever, the soil doesn't matter, a good grower could do it, watch out for tricky ones etc..

Can this thread be renamed?

[HaoBao]

Just realised I only found the article of Cactus Culture Based on Biology of the same name and the book was recommended by Mike P before too. I’ll try and find a copy of the book cheaper than £80

[Tina]

check using ABE books,

[HaoBao]

Thank you Tina, it’s £48.50 on there which is much cheaper than £80 but unfortunately still not as cheap as me.

There was one on Amazon for £754.28 with free delivery

[HaoBao]

These pots are taking longer to dry out than I thought they would. They were sat in water for 30 minutes, then left to drain and they haven’t had a fan or lights on them.

First one to dry is no surprise being just granite.

Right column is the percentage of water that has come out.

The John Innes No.2 (JI) I started a couple of days later so that time is at the bottom.

Can see why the small akadama is good for seeds too

[HaoBao]

These are the results after soaking for 30 minutes, then drying without a fan or lights, just indoors at room temperature.

Kanuma, Pumice and Lava Rock were straight out the bag, so sizes range from 1-6mm

Small akadama is about 2mm

Akadama is about 3-6mm

Kyo-Dama is about 3-5mm

Granite is 4mm

Bigger image here https://i.redd.it/acru47kt2vk61.jpg