Ever since Green Culture Singapore member sixhunter introduced me to this particular type of gravel-like planting media, I haven’t touched anything like perlite, vermiculite, or even the higher quality Indonesian burnt earth (IBE) at all. The volcanic sand from World Farm looks like coarse gravel, and is slightly dusty.

Before using the volcanic sand, it is preferable if you do one level of sifting, to separate the finer gravels from the much coarser ones. You may use it unwashed on ornamental or edible plants without any problems. However, I soak and wash the fine gravels over two days if I want to use them on my carnivorous plants, because CPs are a lot more finnicky in terms of their growing conditions and demands.

I have found it best to line the bottom of the pot with a layer of coarse gravel to improve drainage, and then mix up the subsequent layers with whatever organic planting media along with the fine gravels. This ensures that your media retains moisture but dries out easily so waterlogging doesn’t become a problem.

So far, my edible plants love this particular mix of volcanic sand from World Farm along with Tref potting soil/mix from Far East Flora. My mints are thriving on the moist but not too wet mix; and my carnivorous plants are much easier to handle because I’m able to control the amount of water that remains in the media with a mix of volcanic gravel and Horti moss (peat moss).

They contain no minerals so for edibles or ornamental plants, you’d need to add in fifty percent of organic media; for CPs, the lack of minerals is just fine.