Pistachio nuts are not only delicious and nutritious but their shells can also be used in beneficial ways instead of tossing them out in the trash. You can do all kinds of artistic things with them, or better still use them in inventive ways in your garden. In this article, we’ll find out what to do with pistachio shells in the garden.
What You'll Learn Today
Can Pistachios Shells Be Used In Gardening?
Being made from a natural substance, pistachio shells are kind to the environment and will totally break down and return nutrients to the soil over time. This means they can safely be added to your compost.
But there’s way more you can do with pistachio shells than just composting them and a variety of ways you can use them in your garden as we will find out below.
What Can I Do With Old Pistachio Shells?
What can you do with old pistachio shells other than add them to your compost?
Many plants benefit from a layer of mulch to help maintain soil moisture, reduce weeds, and as it breaks down to add nutrients back to the soil. Pistachio shells can be used for this job, or can be added to other mulch materials.
It will take a long time for the tough pistachio shells to break down so they are good as a durable mulch source. When they do finally decompose they release lots of goodness back into the ground around your plants.
Slugs & Snails
The enemy of all gardeners are slugs and snails. These garden pests can quickly obliterate your tender young plants and vegetables.
Rather than using chemical pellets, which can be deadly not only to your slugs and snails but also to your pets, wage war on them in a more natural way.
Lightly crush your pistachio shells so they have sharp edges and sprinkle them around your plants. By applying a thick top dressing you can also help deter other animal pests from digging in the soil.
An extra bonus is they look attractive too.
It can be really annoying when a cat decides to use the soil around your potted plants as a litter tray. A good way of putting them off is to use pistachio shells as a surface covering around the plants.
By lightly breaking them up they are even more of a deterrent as the sharp edges to the shells are unpleasant on cat paws.
Another bonus is they can look quite attractive too. Do be careful to wash any salt off the shells if they were salted before using them though as this can be detrimental to your plants.
When potting up your plants it’s advisable to add some drainage material to the bottom of the pots before putting in the soil. This prevents the soil from becoming waterlogged which can potentially drown the roots of your plants.
Often small pebbles or stones are used for this purpose, but pistachio shells work really well too.
Simply ensure there are some small holes in the base of the container then line the bottom with your pistachio shells before adding the soil.
This allows the water to drain freely.
Keep in mind that because the shells are a natural material, they will eventually break down in two to three years, so when you repot your plants they will need replacing.
If you’re allowed to have bonfires then pistachio shells can work well as a fire starter. They are woody and contain fat so make excellent kindling.
If you’re going to add whole nuts that are unopened, wrap them in some paper first as they explode as they heat up.
If your plant pots are looking a bit boring, you can liven up their look by gluing pistachio shells to them. If you’re artistic the shells can be arranged in attractive patterns that look fantastic.
Ensure you use a suitable glue that can stand moisture and changing temperatures.
Other than gardening uses, pistachio shells are great for use in crafts, here’s a video to give you some ideas:
Do Pistachio Shells Make Good Compost?
The shells of pistachio nuts are carbon-rich. This means they add structure and air to your compost.
Natural compost you make at home is good in many ways.
- It saves you money on fertilizer
- It enriches the soil
- It nourishes your plants
- It’s environmentally friendly
Pistachio shells break down slowly, so if you add them whole to your compost bin they can take two years or more to decompose.
Keep in mind too that if your pistachio shells have salt on them, then that can be detrimental to the soil as the salt kills beneficial microorganisms. To help them decompose and get rid of the salt, first, soak the shells overnight, then rinse thoroughly in the morning.
Next, smash them up a bit so they are broken into smaller pieces that will break down faster.
The shells are lightweight but any that still aren’t fully broken down may make the compost too sharp for seeds or the delicate roots of baby plants. It is ideal for turning into your flower beds or vegetable patch.
By composting your pistachio shells you’ll help the environment by reducing the amount of methane emissions at the landfill.
Another bonus is the production of beneficial bacteria and fungi that work to break down the shells into humus. Not the type made from chickpeas you use as a dip, but the type that helps soil be rich, light, water-retaining, and benefits the health of your plants.
They are also a good medium to use if you grow orchids as they can help maintain a slight acidity in the soil.
How Long Does It Take Pistachio Shells To Decompose?
Pistachio shells decompose slowly when compared to other natural organic matter. They need to be hard to protect the seed inside them and that tough case will need two to three years to break down.
As we discovered earlier, the process can be made slightly faster by crushing the shells and soaking them in water before adding them to your compost bin.
What Does Salt Do To Soil?
The fine roots of plants take up water by osmosis. High salt concentration in soil slows the movement of water through the root system. If the concentration of salt in the soil is higher than that within the plant’s root cells, instead of the root drawing water from the soil, the soil will draw water from the root, causing the plant to die.
Some plants and trees are more sensitive to salt than others. Fruit trees, and ornamental trees, tomatoes, onions, or lettuce can be particularly prone to salt damage.
Excess sodium also affects the pH balance of the soil and can cause deficiencies in the micronutrients available to the plant.
People sometimes use salt to kill weeds in a driveway for example as it is a cheap and effective solution. The danger is that if the salt leaches into the soil surrounding other plants it will kill them too.
Pistachio shells can be a useful addition to the compost bin or to use for a variety of other gardening uses, from pest deterrent to drainage improvement.
As pistachios are often salted, removal of the salt present on the shells is important before using. This is due to salts’ detrimental effect on beneficial bacteria, and the water uptake of the plants.
Pistachio shells are slow to break down, so some patience is required before you can use compost containing them. Breaking them down as much as possible by grinding or smashing the shells can hasten this.