Recycle your almond, peanut, pecan, pistachio and walnut shells by adding them to your compost.
Why might nut shells be good for the garden?
They help improve soil porosity,
especially heavy clay soils, allowing air and water to move through efficiently.
If possible, grind them up first to speed up decomposition. If this is too much trouble, add them whole and keep the compost moist. Later on, when your compost is ready, if you see that the nut shells have not fully decomposed, you can screen the compost. Screening works especially well if you’ll be using some of the compost for potting soil.
Nut Shells Quick Tips
- Use plenty of nitrogen-rich compost materials along with the shells to balance out the carbon.
- Common English walnut shells are fine in the compost. However, do not use the nuts from the BLACK walnut tree. Every part of a black walnut tree contains juglone. As explained earlier in the section on leaves, juglone is toxic to many plants in the garden. If you have one of these trees, it’s recommended that you plant 50-80 feet away since leaf drop and root invasion could contaminate the soil with juglone. Cabbage, eggplant, peppers, potatoes and tomatoes are especially prone to black walnut poisoning.
Rinse salted shells before adding to the compost.