[header] How to choose organic fertilizer [title] Test your soil. [step] In order to choose the right organic fertilizer for your garden, you need to know the composition of your existing soil. There are a variety of tests that you can do, such as tests for ph, nitrogen, and phosphorus. 
These will let you know the status of different components of your soil. [substeps] Soil test kits for specific aspects of your soil are available at garden supply centers.