Decent compost is hard to find, finding something that seeds might consider worthy of their germination efforts is practically impossible. So, like most determined gardeners, I’ve started making my own mix. I use commercial compost as the starter, ideally with a bit of added John Innes for body but then I sieve out the uncooked bits and add sharp sand for drainage and lightness.
Start with this (other brands available)
Not sure what criteria Which used but is what I sieved out. I’m feeling short-changed… but it goes on the compost heap for more cooking.
add in a few generous scoops of sharp sand
and you get this. I must be getting old, but I’m certain there was a time in the not too distant past when seed compost arrived looking like this.
I don’t use my own compost because it’s full of weed seeds – must do better there.