Plants need fertiliser to grow, produce leaves and vegetables. Depending on the plant you may want to use different types of fertilisers. Check out my article fertilising plants explained.
Banana peels for plant growth
You can use your banana peels to fertilise instead of throwing them away. You may want to ensure that they are organic so you don’t add any unwanted pesticides to your plants. If you do not have time to use them straight away, store them in your freezer.
Benefits for the plants
- High in Potassium (plant growth and strength)
- Smaller amounts of phosphorus and other nutrients beneficial to plant health
- NPK 0.6-0.4-11.5
How to use it?
- Juice – soaked banana peels in water
- Peels digged into the ground near the plant
- Compost/worm farm
Best to use with seedlings to help them grow and keep strong. It can be used as the sole fertiliser for flowering plants especially those producing veggies and fruits. I would recommend it for fairly hardy leafy plants mostly.
Seaweed for healthy bacteria & to prevent diseases
If you live near the beach chances are there are tons of free fertiliser on the sand.
There are different types of seaweed so they may not have exactly the same amount of nutrients and it won’t be standardized as a regular fertiliser you could buy, so you can’t 100% rely on it for fertilising.
Benefits for the plants
- Improve soil moisture thanks to its alginate content
- Bring micronutrients (trace elements and amino acids) to the soil
- Help root health and nutrient absorption
- However it is low in NPK (unless it’s store bought)
How to use it?
- Fermented liquid
- Mulching (lay on the soil around the plants)
- Dried, broken down into powder and mixed into potting mix
- Composting (not suitable for worm farm due to its sodium content)
Best to use with any plants as it will make them stronger, help them to absorb nutrients and be more resistant to diseases.
Precautions
- Regulations: Check local law, where I live in Sydney we are only allowed to pick up to 20L of seaweed per day. Usually you will only be allowed to collect seaweed that has already been detached from the ground and lying on the sand or water.
- Pollution: Be mindful of areas that are liable to pollution, such as downriver of industrial activities or sewage as seaweed is susceptible to contamination.
Stinging nettle for leaf growth
Stinging nettle is an incredibly nutritious plant both for humans and plants. It was used during the second world war when there was food shortage in Europe.
I love this fertiliser because stinging nettle is basically a weed so it’s easy to grow and depending on where you live you may be able to find large quantities of it in green areas.
Benefits for the plants
- High in nitrogen so increase leaf production
- Reasonable amounts of iron and magnesium which are essential to plants
- Improve plant immune system response
- NPK content: 5.6-0.7-3.7
How to use it?
- Fermented tea
- Manure
- Mulching (lay on the soil around the plants)
- Composting
Best for leafy plants who do not produce flowers, fruits or vegetables. This fertiliser is also ideal for heavy feeders such as celery plants and not recommended for beans or peas.
Precautions
The stinging nettle as indicated in its name contains silica spikes on its leaves which is irritant for the skin. It is recommended to wear gloves to pick up the stems.
Comfrey for health growth + good complement to stinging nettle
Comfrey is a perennial herb that is easy to grow in average soil. So you will need to plant it and grow it to be able to use it. You can cut the leaves to make a fertiliser.
Benefits for the plants
- High in potassium which contribute to plant growth and strenght
- Reasonable amounts of calcium
- NPK content: 1.8-0.5- 5.3
How to use it?
- Fermented tea
- Manure
- Mulching (lay on the soil around the plants)
- Composting
Best for all plants but does not contain a lot of nitrogen and phosphorus, so it needs to be complemented with phosphorus and high nitrogen fertiliser like sting nettle.
Human Hair for leaves growth
Human hair contains a fair amount of nitrogen which can be beneficial to plants. I used the hair collected after cleaning my hairbrush and so far it’s been working well! You could also collect your hair when you cut them.
Benefits for the plants
- High in nitrogen so beneficial for leafy greens
- Improve water retention of plants
- Also great to repel slugs
How to use it?
- Mixed in compost mixed
- Mulching (lay on the soil around the plants)
- Composting
Best for leafy plants who do not produce flowers, fruits or vegetables. As it retains water, it may not be suitable for plants who require good drainage.
Coffee ground – improve drainage + increase acidity
This is such a great way to reuse something that would end up in landfill otherwise. If you don’t have a domestic machine, you can ask a cafes which produce a fair amount everyday and would be happy to hand some over to you!
Benefits for the plants
- High in nitrogen
- Improve drainage, water retention and aeration in soil
- help microorganisms beneficial to plant growth thrive as well as attract earthworms
- Increase soil acidity (only if fresh)
- NPK content: 2.1-0.3-0.3
How to use it?
- Add to compost
- Mix with soil/potting mix
- Sprinkle near plants
Best for leafy plants who do not produce flowers, fruits or vegetables. It is not recommended for beans or peas.
If you had coffee ground directly to the ground, some of the nitrogen will not be directly available to plants compared to when added to compost.
Precautions
Do not add big amounts if you add it near the plants as it will create a thick layer that will prevent water absorption.
Tea leaves, general health
If you use tea leaves, you can use these leaves to fertilise plants. Do not use tea bags unless they are fully compostable. Most of them contain plastic which will not break down rapidly.
Benefits for the plants
- High in nitrogen and contain small amount of potassium and phosphorus
- Help with water retention
How to use it?
- Add to compost
- Mix with soil/potting mix
- Sprinkle near plants
Best for leafy plants who do not produce flowers, fruits or vegetables. It is not recommended for beans or peas.
If you sprinkle it near the plants, the nitrogen will not be fully available to the plants.
The Multi fertiliser
As you could see above each of these fertilisers contains different nutrients and have various benefits for plants. It’s a great idea to combine some of them to create a multi fertiliser for plants.
I like to combine comfrey, nettle, banana peels and seaweed!
Bottom line
These fertilisers are great to give a free boost to your plants, but if you are really serious about gardening you may want to invest in a standardised fertiliser to ensure your plants get what they need at all times.