Gardening is more than just a hobby; it’s a way to connect with the earth while making sustainable choices for our environment—and it doesn’t have to cost the earth, either. By creating homemade fertilisers using items you might already have around the house, you can nurture your garden, save money, and contribute to a healthier ecosystem free of synthetic chemicals.
Before getting started, remember to test your soil. Understanding what your soil lacks ensures you can give your plants exactly what they need—nothing more, nothing less. Over-fertilising, no matter how natural the source, can harm plants and upset the soil’s natural balance.
Here’s a list of some of the most effective homemade fertilisers you can try, what they bring to your garden, and how to use them.
1. Comfrey Tea
Nutrients: potassium, potassium, nitrogen
How to Prepare: Steep well-rotted compost in water for 24–48 hours. Use a ratio of 1 part compost to 5 parts water.
How to Use: Dilute further if needed and pour around the base of your plants to improve soil fertility and encourage healthy growth.
See our Blog on Comfrey Tea here
2. Animal Manure
Benefits: Rich in nitrogen, phosphorus, and potassium, manure helps plants grow vigorously.
How to Prepare: Allow the manure to age for several months to reduce its harshness.
How to Use: Work aged manure into your soil or mix it with water to make a nutrient-rich tea.
3. Banana Skins
Benefits: Loaded with potassium and phosphorus, banana skins are ideal for flowering plants.
How to Prepare: Chop the skins into small pieces or blend them with water for faster decomposition.
How to Use: Bury pieces in the soil near your plants’ roots or pour the blended mixture around them.
4. Seaweed
Benefits: Rich in trace elements and plant hormones, seaweed promotes plant health and resilience.
How to Prepare: Rinse any salt off collected seaweed, then soak it in water for a few weeks to create a liquid fertiliser.
How to Use: Dilute and water your plants with this nutrient-packed tonic.
5. Epsom Salts
Benefits: A great source of magnesium and sulphur, which are essential for photosynthesis and plant health.
How to Prepare: Dissolve one tablespoon of Epsom salts in a gallon of water.
How to Use: Spray the solution onto leaves or water at the base of the plant.
6. Bone Meal
Benefits: Full of phosphorus and calcium, bone meal fosters strong roots and healthy flowers.
How to Prepare: Grind clean, dry bones into a fine powder.
How to Use: Mix into the soil at the base of plants before planting.
7. Fish Emulsion
Benefits: Packed with nitrogen, phosphorus, and trace minerals, it’s excellent for leafy vegetables.
How to Prepare: Steep fish scraps in water for several weeks until the liquid ferments.
How to Use: Dilute the liquid (1 part emulsion to 10 parts water) and apply it as a plant fertiliser.
8. Molasses
Benefits: Feeds beneficial soil microbes and helps increase microbial activity.
How to Prepare: Mix one tablespoon of molasses with a gallon of water.
How to Use: Water your plants or add it to compost tea to give your soil extra life.
9. Coffee Grounds
Benefits: High in nitrogen, coffee grounds are especially great for acid-loving plants.
How to Prepare: Dry used coffee grounds to avoid clumping and potential fungal growth.
How to Use: Sprinkle them lightly onto the soil or mix them into compost.
10. Tea Leaves
Benefits: Tea leaves add nitrogen to the soil and improve its structure.
How to Prepare: Dry used leaves or compost them. Ensure no tea bags contain plastics.
How to Use: Add tea leaves directly into the soil or mix them into your compost bin.
11. Grass Clippings
Benefits: Fresh grass provides nitrogen, while dried clippings make excellent mulch.
How to Prepare: Allow the clippings to dry before use to prevent mould.
How to Use: Spread dried clippings around the base of your plants to retain moisture.
12. Egg Shells
Benefits: Eggshells add calcium to the soil, which prevents issues like blossom-end rot in tomatoes.
How to Prepare: Crush shells into small pieces or grind into a powder.
How to Use: Scatter the shells over the soil or blend them into the compost.
13. Wood Ash
Benefits: Provides your garden with potassium and trace nutrients.
How to Prepare: Use ash from untreated wood, and store it in a dry place to avoid clumping.
How to Use: Sprinkle it lightly around your garden; avoid overuse as it can raise soil pH.
14. Stinging Nettle Tea
Benefits: Contains nitrogen, iron, and other trace elements, making it a fantastic plant tonic.
How to Prepare: Steep nettle leaves in water for a few weeks to produce a nutrient-rich tea.
How to Use: Dilute the liquid and use as a foliar spray or soil fertiliser.
15. Vegetable Cooking Water
Benefits: Packed with minerals leached from vegetables during cooking.
How to Prepare: Simply save the water after boiling vegetables. Avoid over-salted water.
How to Use: Allow the water to cool before pouring it onto garden soil.
16. Old Aquarium Water
Benefits: This water contains nitrogen, phosphorus, and potassium from fish waste.
How to Prepare: Use water from a freshwater aquarium (not saltwater).
How to Use: Pour gently onto the soil around your plants, avoiding foliage.
Final Thoughts
Switching from synthetic fertilisers to these homemade alternatives isn’t just a budget-friendly move—it’s a commitment to sustainable, eco-friendly gardening. By using what you already have and composting kitchen waste, you can reduce landfill contributions while creating a thriving garden ecosystem.
Remember, every plant has its own unique requirements, so test your soil, observe your garden, and apply fertilisers in moderation. Now’s the time to roll up your sleeves, improve your soil health and nurture your plants with natural, affordable care.
Further Reading: How to Discover Your Soil Type (And Why It Matters),
Take a look at our Great Range of Grow Your Own Seed Sets