raised bed on top of fire pit

Asked July 10, 2017, 4:53 PM EDT

I have a fire pit area where I have been burning brush. Can I put my new raised bed garden on top without doing anything, or do I need to remove the remaining ash (left from the burning)? NOTE: only branches were burned, no pressure treated wood.

Harford County Maryland

1 Response

The answer depends on what you hope to grow (and their root depth), how much wood ash is there, and how deep your are planning for your raised bed to be.

Wood ash is basic and can be used as a soil amendment to "sweeten" or raise soil pH. It also has a small amount of phosphorus and potassium.
You don't need a lot though, and too much can be bad if plant roots will reach that deeply.
The recommended yearly application rate is 25-50 lbs./1,000 sq. ft.

Let us know your thoughts.