How much organic matter should I add to my garden?

How much organic matter should I add to my garden?

Tracy DiSabato-Aust (Garden Designer and Author) gives expert video advice on: What are 'soil amendments'?; What is the difference between 'organic' and 'inorganic' soil amendments?; What is 'leaf humus'? and more...

A general rule of thumb that I like to do, based on a soil test to see where your organic matter content is, is that you can test for that, but normally we're adding about 4 inches of organic matter content. We usually start with disturbed urban soil, which is about 2% organic matter. Most plants, particularly herbaceous plants, require at least 6% organic matter content.