One of the most interesting ways to use sourdough starter is in your garden. Now I'm not just talking about composting your sourdough starter. I'm talking about actually using your sourdough starter (and discard) to fertilise your plants!
Whether you're an indoor or outdoor gardener, this blog will teach you how to use sourdough starter to boost your soil and plants.
Teaming with good bacteria and microbes your soil and plants will love, your fermented sourdough starter could be the best homemade fertiliser you've ever used!
You can use sourdough discard in your garden in the following ways:
- Use diluted sourdough discard as a liquid nutrient boost
- Use dried sourdough starter as a soil conditioner
- Add it to your backyard compost pile
- Place it into a bokashi bucket
- Feed it to your backyard chickens
- Add to your vermicompost or worm farm
Why Use Sourdough Starter In The Garden?
Sourdough starter is teaming with good bacteria, yeast and microbes which your will enrich your soil and make your indoor and outdoor plants thrive.
It is a living, thriving culture. In fact, you may have heard it referred to as a "scoby" which stands for symbiotic culture of bacteria and yeast.
It's alive!! Just like your plants and soil.
Using sourdough starter discard in your garden may not be something you've ever thought of ... until now. Maybe you've only been using your discard in baked goods?
Using sourdough starter in the garden is a great way of managing sourdough discard without waste. It completes the cycle of life, going back into the soil to enrich food we grow.
I have a large collection of indoor plants that are all thriving, as well as an ever growing outdoor garden full of edible vegetables and herbs, as well as evergreens and flowers.
They all love sourdough starter as part of their regular fertilisation schedule.
Given that sourdough starter is made from wheat, which is grown in soil, it seems only natural to continue the cycle of enriching the soil.
You should never use bleached flour of any kind in your sourdough starter.
This is because the bleaching process strips the flour of many of the natural yeasts and microbes that are required when creating a sourdough starter.
How To Feed Sourdough Starter To Indoor Plants
Feeding indoor plants can be a little tricky. You don't want to have messy fertiliser that will stain floors or furniture.
While sourdough starter can be diluted with water to create a liquid fertiliser, it can stain plant leaves and leave a white residue. Not what you want for glossy indoor plants.
The easiest way to use sourdough starter to nourish indoor plants is to use dried sourdough starter as a soil conditioner.
Add the dried sourdough starter to your soil when potting up your indoor plants or sprinkle on top of the soil for a microbe boost. I use around 15g of dried sourdough starter per small pot and 30 to 50g for larger pots.
If you are able to take your indoor plants outside to water, you may be able to use liquid sourdough starter to feed them.
Add 100g of sourdough starter discard to a 1L jar and top up with water. Give the jar a good shake. Now add this liquid to a large tub and top up with water. Once it has a few inches of water in it, gently place your potted indoor plants into the water.
This is called bottom watering and it allows them to take up the water through the bottom of the pot. It's an easy and fairly mess free way to apply sourdough starter to your indoor plants.
Let the plants sit for a few hours, before drying the bottom of the pots and returning them to their place in your home.
This bottom watering method will avoid the white stains on the leaves. I often use my laundry tub or bath tub for this too as it saves me taking all my plants outside.
Using Sourdough Starter In Your Outdoor Garden
If you have outdoor garden beds that you would like to fertilise, there are a few ways you can add sourdough starter to them. You need to worry less about mess in outdoor garden beds, so you can be a little more liberal with your starter.
- Add 100g of sourdough starter discard to a jar and top up with water. Give the jar a good shake. Now tip the liquid from the jar into a 9L watering can and top up with water. Use this watering can to liberally soak your pots and garden beds. You can pour the liquid over your plants/leaves or just around the soil. The liquid will leave a white residue on some foliage plants. It can be easily rinsed off the next time you water.
- Alternatively, you can use pulverised dried sourdough starter as a soil conditioner. Add the dried sourdough starter to your soil when potting up patio plants or sprinkle on top of the soil in your garden beds for a microbe boost. I use around 15 to 30g of dried sourdough starter in my outdoor pots (depending on their size). I sprinkle it liberally on my outdoor garden beds with great results.
- Add your sourdough starter discard to your compost heap to give it a microbe boost.
- Sourdough discard makes a lovely treat for backyard chickens. You can see how to give sourdough discard to chickens here.
How To Compost Sourdough Discard
If you have a compost pile, sourdough discard can be a welcome addition. You can add it straight into the compost without doing anything to it.
The microbes, yeast and bacteria in the sourdough starter will be a great boost to the microbes already active in your compost.
It's an easy and waste free way to manage sourdough discard.
Sourdough starter is also suitable to add to a Bokashi Bucket.
Can You Feed Sourdough Discard To Worms?
Yes you can add sourdough discard (unfed sourdough starter) to your worm farm or vermicompost. You should only add small amounts at a time, since sourdough discard is wet and you don't want to overwhelm your worm farm.
Give Your Plants Even More Love
If you want to give your plants an even bigger boost when feeding them sourdough starter, you can add some of the following to the mixture:
- Soak 1 - 2 banana peels in a jar of water for 24 hours. Add the jar of water to the watering can with your sourdough starter liquid for a boost of potassium.
- Add 1 litre of milk to the watering can with your sourdough starter liquid for a boost of calcium (it's best to bottom water indoor plants so you don't stain their leaves).
- If you are adding dried sourdough starter to your soil, add some dried egg shells and/or coffee grinds to your food processor before you pulverise it. This will give your powder even more nourishing powers and add calcium and nitrogen to the soil, along with the goodness from your sourdough starter fertiliser. I dry egg shells and coffee grinds and then mix with sourdough starter and use a few scoops when potting up plants.
Things To Be Aware Of When Using Sourdough Starter In Your Garden
Sourdough starter or discard is made of naturally occurring ingredients, however there are still a few things you should be aware of when using it in your garden:
- Don't add too much dried sourdough starter to your soil at a time. If you overload your soil, it can become moldy when you water it. Less is more!
- Diluted sourdough starter can leave a white film on the leaves of your plants. This is not so much a problem outside because you can easily rinse it off when you water next. But it's something to be aware of when using it inside. Bottom watering is best in this case!
- Like any fertiliser or soil booster, consider which plants you are adding it to and their nutrient needs. Some plants will do better than others and you might need to adjust the amounts you use. I tend to use more in the summer and back off in the winter when my plants are dormant.