willow wrote:.......... Very interesting discussion going on here. I have learned alot by reading such discussions as fairly new to cactus growing (although Ive had a couple for a long time) .......... I have now repotted from peat which i previously thought was the correct stuff! ......... Thankyou all for this discussion
Thank you for participating in it, Willow. I would like to clarify my views relating to this topic. First, I am not in "lock-step" with "The Stone Eaters", but I do primarily use mineral based growing media and have had great success doing so.
I have had particularly good success growing Brazilian cacti, in containers, here in Tucson, Arizona for several years mostly using a medium consisting of 80% coarse pumice and 20% aged and weathered pine bark. Since adopting that mix my plants have grown consistently healthy and robust with great spination and they have produced bountiful flowers and fruit. I still have a number of cacti growing in that mix in greenhouses at Dan Bach's Cactus Nursery here in Tucson.
As I have mentioned in a companion post, I now grow my plants at our townhome in plastic pots using straight pumice and Hydroponics Drain-to-Waste methodology (nutrients supplied via a liquid fertilizer containing micro-nutrients). I am doing that because I need my potted plants to be light weight due to my age, edema, arthritic knees and a winter maintenance regimen which involves staging my plants indoors on south facing windowsills at night, and during cold days, and carrying them outside to the patio for the benefits of sunshine and fresh air during the 60°F+ (approx. 16°C+) days that we frequently experience during our Tucson winters. I can safely carry two trays each containing eight plants in small square plastic pots (but no more). I am very unsteady on my feet these days and have already fallen several times -- twice hurting myself severely -- I cannot afford to fall again. Watering is a chore and I like the fact that it is almost impossible to over-water using this growing medium (I often forget the previous watering date).
So that is how I grow my plants here in Tucson using predominantly mineral growing media -- which I do like. But that is for me in my circumstances -- it may not work at all well for you, Willow, or any other enthusiast for that matter. I think you are on the right track to growing success by participating in these discussions and, of course, reading authoritative books (and researching via the Internet). Listen to all sides during discussions -- the counterpoints are often the most instructive and valid.
In summary, I think that selection of growing media should be based on the species of plants grown, how they are grown and where they are grown -- always bearing in mind the need for good drainage, root aeration and nutrition.