rock rust

I have a couple of significant questions for you on the crunchy topic of real food.
Here at Mother’s Garden, as some of you might have twigged, we have never put any chemicals on the land in the nine years we have been ploughing our furrow here in the Priorat mountains, and are reasonably confident that it was untainted for at least a decade before that.
The challenge is to keep the soil happy and healthy, and our compost and pony poo wheel-barrowing works up to a point. Now we are looking deeply into a further source of goodness, natural minerals and nutrients.
Who has heard of, or indeed applies, rock dust to their garden? Have you read We Want Real Food, by Graham Harvey? This year we aim to use ground rock on part of vegetable patch, but the challenge is to find some.
Now we have discovered that the top farm terraces, populated by almond trees, are fundamentally ground granite. And from there comes our spring water, spouting into a water reservoir which has a two-inch squidge of silt on the bottom. This could well be a hey presto moment. What do you think? We will keep you posted, because we are on a mission. This is important. For all man’s meddling and the dire consequences, the answer might just be under our feet.