Let's just say: I take my hobbies seriously! :D
That stuff in the back is 100 litres of perlite, a cheap, lightweight volcanic material that provides aeration in potting mixes! 🌱
The other main component is going to be coir (aka coconut fibre), which has the opposite property: it holds water really well! I found it in this brick shape.
Perlite looks and feels like small pebbles of styrofoam. It wasn't as dusty as I thought, but let's still give it a good rinse!
...and this should, in theory, be an excellent substrate for starting seeds! This is a "soil-less" mix, and it's pretty much void of nutrients; the seeds already pack everything they need to get started. Or so I've heard. I barely know what I'm doing! :D
@blinry Sounds like my experiments right now! This mix sounds very close to "Mel's Mix" which is used for square foot gardening. 1:1:1 vermiculite : peat moss : compost. But you can switch the vermiculite with perlite for better drainage, and peat moss for coconut coir. I decided to try it when I found this post from someone who tested it against some others: https://journeywithjill.net/gardening/2020/03/09/3-raised-bed-soil-mixes-compared/
@holly Oooh interesting! Thanks so much for your input, learning from your experiences is great! :)
@holly Do you use vermiculite yourself? Do you have opinions on vermiculite vs perlite, in the context of potted indoor plants? :)
@blinry According to this random internet person, vermiculite retains more water, perlite is better for drainage. I tend to get fungus gnats in my indoor plants, so I picked perlite to hopefully reduce the chance of standing water. And I'm using perlite for outdoor plants, as well, because with all the rain we get here drainage is a priority. https://www.gardenbetty.com/perlite-vs-vermiculite/
@blinry I plan to use worm castings for the compost, but my worms died over the winter this year and the new ones are lazy, so my worm factory hasn't been very productive so far. I tried to mix pellet fertilizer with potting soil for the compost part, but it's really not the same -- whenever I do add a topdressing of worm casting to my plants they have a burst of growth, so clearly that's what they really want.