Please note that this post may contain affiliate links. You can read my full affiliate disclosure at the bottom of the page.
The use of kitchen scraps for the garden can go beyond the normal compost materials. Oyster shells also have use in your home garden too.
If you’re wondering what are oyster shells that you use in the garden, it’s just like it sounds. Ground-up or crushed oyster shells from the oysters that you eat.
Or if you are like me, and go BLECH! at the thought of eating oysters, but still want to use them in your garden then you are in luck. You can buy them already ground up and ready to use. But don’t worry, if you have leftover oyster shells we will go over how to crush oyster shells to use in the garden.
Oyster Shells for Your Garden
Down to Earth Organic All Natural Oyster Shell Fertilizer
Are Oyster Shells Good For The Garden?
So what is just so good about crushed oyster shells being used in your garden?
And what do oyster shells do for plants in the garden?
- Balance soil pH levels
- Improve nitrate update by plants.
- Helps with enzymes forming in the soil.
- Better growth rates for leafy greens and vegetables. (source)
- Aids in the prevention of some garden pests.
Oyster shells contain high levels of calcium carbonate and other macro-nutrients. The levels of these will depend on the different types of oysters. Also, other forms of crustacean shells can be used for similar benefits. So feel free to experiment if you had some crab shells leftover from a meal.
Adding crushed oyster shells to garden soil adds a way to have a long release of these nutrients that your plants can use.
Oyster shells also help regulate the pH levels of your garden soil. This regulation of pH levels helps increase the intake of nitrates by the plants in your garden. More nitrate uptake means healthier and bigger leafy greens and vegetables.
Another great bonus of using oyster shells in your garden soil is that they can help keep pests like moles and voles away. And who doesn’t like some natural pest repellent in the garden?
When To Add Oyster Shells to Your Garden
The best time of year to add oyster shells is either in late spring or early summer.
Adding them to your garden directly will give you extra benefits like pest control and better soil pH regulation.
You can add crushed oyster shells over your garden soil. Some people like to do thick layers when applying them to the garden this way.
Just be careful when applying them in layers, as oyster shells can be very sharp and you don’t want someone walking on them barefoot.
Can You Add Oyster Shells To Compost?
Yes, you can add oyster shells to your compost tumbler or compost pile.
In fact, it has been shown that composted oyster shells are more effective than fresh oyster shells for some of the benefits. (source)
If you are mainly looking to achieve better enzymes and improved nitrate uptake, you can just add them to your compost and then they will get added to your garden when you add more compost. Using them in the compost this way will also help add beneficial microbes to your compost.
How Do You Grind Oyster Shells For The Garden?
What you will need to grind or crush your own oyster shells:
- Pot
- Water
- Hammer/Mallet
- Towel
- Ziploc Bag
- Mortar and Pestle (optional)
First you want to be sure to boil your shells before breaking them down. This way you are sure you have killed any bacteria that could still be on the shells.
After boiling them set them out to dry thoroughly.
Once they are dry put them in a Ziploc bag and seal it, then cover the bag with a towel. This will keep the shells in the bag in case the bag gets punctured during the crushing process.
Now start hitting the towel with your mallet (or hammer). Mallets seem to be a bit easier to use for this process.
Keep hitting and crushing down the shells until you get the consistency of crushed oyster shells that you are looking for.
If you are wanting to get a nice fine consistency for your oyster shells then you can take the crushed shells from the Ziploc bag after they have been broken down and continue to grind them up in a mortar and pestle.
Pin This For Later:
