Contact a laboratory or county extension office that tests soil for nutrients. Collect soil samples from your garden and landscape, per the lab's particular guidelines. Typically you must collect several samples for an accurate reading. The results indicate how much fertilizer, if any, you need to apply to effectively grow purple hull peas in your garden.
Select a low nitrogen fertilizer to use for your soil bed in lieu of testing your soil. A granular fertilizer labeled 8-24-24 or 5-10-10 typically works well for growing purple hull peas.
Measure out approximately 2 to 3 pounds of fertilizer for every 100 feet of row. Evenly broadcast the fertilizer across the garden bed 10 days before planting, recommends Clemson University.