Sour soil

Q: I am digging a new flowerbed. The soil is very black and it looks like something has been burned there a long time ago. There are charcoal pieces a foot deep. The soil smells sour and rotten. What can I add to the soil to sweeten it? Lime perhaps?

The soil is sour because there is very little oxygen in it. Usually charcoal can remove odours and all sorts of sour agents if it has a good quantity of oxygen in it. I suspect there is a drainage problem and the soil is a little heavy to begin with.
My suggestion is to increase the pore size so it can aerate better. In this case a little sand, bark mulch and some compost will help. Mix this into the soil and use a dutch hoe to sift the soil. If we make omlettes and merangues we are soft with the eggs and fold the oxygen in. Do the same with the soil and the additives/amendments. Soft round circular motions will introduce more oxygen. The sand and bark mulch will give you the drainage pattern so water and oxygen can percolate down.