Uses for Pistachio Shells
Empty pistachio shells can be recycled in several ways. If unsalted, the shells need neither washing nor drying before reuse but washing is simple if this is not the case. Practical uses include as a fire starter, just as crumpled paper is used as kindling; to line the bottom of pots containing houseplants, for drainage and retention of soil for up to two years; as a mulch for shrubs and plants that require acid soils; as a medium for orchids; and as an addition to a compost pile designed for wood items that take longer to decompose than leafy materials, taking up to a year for pistachio shells to decompose unless soil is added to the mix. Shells from salted pistachios can also be placed around the base of plants to deter slugs and snails. Craft uses for the shells include Christmas tree ornaments, jewellery, mosaics, and rattles. Research indicates that pistachio shells may be helpful in cleaning up pollution created by mercury emissions.
The list of uses for pistachio shells is not limited to crafts. Among their many uses, scientists view the leftover shells as a source of renewable fuel, and as a means of controlling mercury emissions in power plants.
- Mosaics are always a simple project for using pistachio shells. The uniform shape and size of the shells makes projects easy to plan. Coloring the shells in batches with food coloring diluted with water. Drain and dry them, then use the different color variations to fill a canvas by gluing the shells in place. Rinse the shells first if they were salted nuts.
- The wood in the pistachio shell is high in oils. The curved shape keeps them from flattening together and the resulting air space combined with the oils makes them a great fire-starter. Collect them in decorative basket if you are fond of eating pistachios often. When you are ready to start the fire, just grab a handful. Start them with a little crumpled paper, just as you would kindling.
Christmas Tree Ornaments
- Make unique Christmas tree ornaments with those leftover shells. Rinse them clean, drain and dry before gluing them together. One fun idea is hot gluing them over an egg-shaped piece of Styrofoam so the shells overlap, kind of like a pine cone. Either paint them or dip them in glitter.
- Instead of trying to find bits of broken pottery to cover the drainage hole in the bottom of your houseplant, toss in a few pistachio shells instead. They hold the potting soil back from washing out with the water. As time passes, they decompose, so change them every year or two with fresh shells.
- Toss the rinsed out shells under your favorite acid-loving shrubs like roses or azaleas. They conserve moisture under the plants, discourage weeds and slowly decompose. They are a little too sharp to use in areas where you walk, so keep them confined to non-walking areas.
- If you have the space and time, the pistachio shells decompose into compost. Like other wood sources, they need moisture and time to break down the strong cellulose bonds that hold them together. If you mix them into a compost pile with other plant matter, you might be able to speed up the process, but they need eight to 12 months to fall apart into compost.
Make necklaces or bracelets with the shells, just as you would seashells. Try different methods like staining them with wood stain or painting them with bright paint, then use a little polyurethane to shine them. Drill a tiny hole with a jeweller's drill bit and thread them together with strong thread or mono-filament string.