Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. It is commonly used as an aeration amendment in soils. I prefer it to perlite because it doesn't break down as quickly and is also heavier, meaning it's less likely to float to the surface over time from repeated watering.
If ordering the cubic ft bag size, the pumice we stock is medium. If you are looking for pumice by the yard or pallet quantities on bagged pumice, then it's available in fine, medium, or large sizes.
NOTE: In our soils, we use pumice at a rate of 33-37% of our total media and a combination of 1/3 large pumice and 2/3 medium pumice. Our pumice is sourced from Oregon.
Customer Reviews
Website didn't say what size the chunks were. I was hoping for 1/4" minus, and left a note on my order to that effect (needed it ASAP, so didn't want to wait for a query and reply), but it was 1/4"-3/8", which is bigger than what I usually use (for potting soil), but it worked okay, except that it seems like the wild birds around here like to pick it out of the pots and leave it lying around. It must look like food to them, until they feel the texture! ;) Was a good deal, price-wise.
Nice and clean and great size. Plants love it.
The Pumice Stone works in my vegetable garden outside
Great stuff
Second time purchase. Love this bulk, non Amazon option, which is relatively local for me (PNW), it's made available to low volume retail customers, and KIS's customer service is outstanding. I wish the product were a little less coarse (I use it for indoor Haworthias), but with that said, I will continue to buy from KIS!