BCSS - Forum

Calling growers who use pure pumice, no organic matter. I'm trying an experiment this year, following a conversation with Ingo Breuer, of potting plants into pure pumice. Nothing else, no organic matter. Do any of you already do this? If so, do you water more frequently than with plants which have some organic material added to the substrate?
Any pest problems?

I grow all my cacti in pure moler clay (sanicat cat litter), no organic matter at all. I actually got the idea after buying a few plants from Ingo seven or eight years ago. The root systems on his plants were extremely healthy. The results have been revelatory to someone who had used a standard JI and grit mix for 30 years previously. The plants grow more strongly and havd never looked better. I actually water a lot less than before and although I may lose a couple of plants each year it's never from rot. There has been no difference in the amount of pests experienced.

I haven't gone over totally to using just pumice for all my plants, but I have for some that previously I found difficult to grow well. The difference is significant, root systems much stronger, and thus the plant. I water these carefully, as I did before, and of course they do need feeding regularly, but then so does every plant in a normal JI/grit mix after a year or so.

Brilliant, thanks! I'm excited to give this a try.

Where do you get pumice?

Herts Mike wrote: ↑Sat Feb 16, 2019 1:51 pm Where do you get pumice?

You can get it online- Der-Naturstein-Garten via Amazon (this is the best mix of sizes I think), also Specialist Aggregates do gravel, which is a little on the big side, but they also do pumice sand.
Not worth buying unless in bulk though.

I grow my Pachypodiums in pure pumice. The difference: they keep all their leaves throughout winter, ones in organic matter lose theirs. As pumice is expensive, I haven't gone over completely but it certainly opens up the soil and allows air to get to the roots. I use it for my Aloe polyphylla as well, which makes the pot a lot lighter than normal and easier to carry. In watering terms, I also water less and feed continuously at 50% strength. No pests that I've experienced.

I got mine from Kaizen Bonsai a few years ago, the quality is very good. They sell both sizes and now label it as 'cactus soil' as well. They also have various types of clay soils as well. Link below:

https://www.kaizenbonsai.com/catalogsea ... /?q=pumice

They look so much nicer with leaves on, last watered in September.

Pachypodium densiflorum v. densiflorum.


Pachypodium densiflorum v. brevicalyx


And a Fockea to show it's not just Pachypodiums that like growing in pumice.

Mike, it says £8 but doesn't say what you get for it that I can see.

I am sufficiently convinced by the argument and have repotted a dozen Stapeliads into pur cat litter to monitor their progress this year.

Herts Mike wrote: ↑Sat Feb 16, 2019 3:52 pm Mike, it says £8 but doesn't say what you get for it that I can see.

Hi Mike,

For both grades it's £8 for 7L and £11.95 for 14L, roughly double the price of cat litter, but oh so much better …