QUESTION: Can you use too much compost?
ANSWER: It is possible to use more compost than is healthy for your plants, just like it is with fertilizer. Using too much compost can result in having more nutrients in the soil than is healthy for your plants, which can have negative effects for them. Limit compost to a layer of one or two inches that’s worked down into the loosened soil beneath when you’re setting up a new garden bed in a space that hasn’t been used before.
You can spread a layer of compost between half an inch and one inch thick over the top of existing garden beds, and it won’t be necessary to work the compost into the soil in this case. Lawns benefit from compost in amounts up to a quarter inch spread across the top each year.