What is grit?
I am a big fan of Gardeners World....but I live in the Pacific Northwest of the US. On the show grit is often recommended to add to potting mix. Based on searching past discussions, I assume that it is washed salt-free sharp sand ....but sometimes it looks like small pebbles. A search on Amazon for gardening grit shows results for vermiculite, perlite, pumice. I don't think any of these are the same as what the Brits call grit. Any insight?