Starting this thread in the hope that it will begin a great discussion about this garden amendment. Amazing info online. Seems to be a miraculous product.
Just ordered a cubic foot for $50 with free shipping.
Bio char MUST be "charged". That means you make a tea with manure, urine, live whey, compost and such and soak the char in that for 2 weeks, then apply.
If you don't charge it, it will not work and may be detremental for your garden for the first year or two. That is because the carbon absorbs nutrients from the soil unless charged first.
Char is effective if as little as 3% of the root area is char.
Will post results.