How much manure do I mix with potting soil?
Use an amount of composted manure equal to one-fifth the amount of potting soil you need. Consider this amount to be “1 part.”
Use 20 to 30 pounds of manure for every 100 square feet of garden. Do not use too much. Do not use fresh manure because it can injure plants.
Beside this, Can you put too much manure in your garden?
Proper use of manure in the garden can supply your plants with nutrients and help improve soil structure.