Step 1: Clean the Shells
After eating the pistachios, collect the shells and clean them thoroughly to remove any salt or seasonings, which could be harmful to your plants. Rinse the shells with cold water and let them air dry completely.
Step 2: Crush the Shells
Place the dried shells in a sturdy bag or between layers of cloth and use a rolling pin or mallet to crush them into smaller pieces. This step helps break up the tough shells and makes grinding easier.
Step 3: Grind into powder
Using a food processor, blender, or coffee grinder, grind the crushed shells into a fine powder. Be patient, as the hard nature of pistachio shells may require several rounds of grinding. The end result should be a powdery substance that can be easily incorporated into soil or other gardening materials.
