N. northiana - grown under different lighting conditions

[Cindy]

Hmm...I never thought of it but it does resemble terra cotta in colour. Just as hard...but the texture is like lava rock. Porous.

The burnt earth/clay/soil are the red rocks in the pic below. The size can vary from 2" large ones to tiny powdery bits.

 

[rsivertsen]

I wish this stuff was commercially available in horticultural grade (without dyes or toxins). I'd love to get my hands on some of this! - Rich

 

[Cindy]

Interestingly, the burnt clay is supposed to be mineral free after being heated. So how N. northiana manages to do so well in it...it is a mystery.