How to Make Your Own Organic Fertilizer From Household Scraps

Why Make Your Own Organic Fertilizer

A typical Filipino household generates 0.3 to 0.5 kilograms of organic kitchen waste daily - banana peels, eggshells, coffee grounds, rice washing water, vegetable scraps, and fish trimmings. Instead of sending this waste to landfills, you can convert it into effective plant fertilizer at zero cost. Commercial organic fertilizers cost 100 to 500 pesos per kilogram, while homemade versions use ingredients you would otherwise throw away.

DIY organic fertilizers also offer advantages over synthetic options. They release nutrients slowly, reducing the risk of fertilizer burn. They feed soil microorganisms that improve soil structure over time. And they contain a wider range of trace minerals than most commercial formulations. Here are 8 proven recipes that Filipino gardeners use successfully in Metro Manila and nearby areas.

1. Banana Peel Fertilizer

Banana peels contain approximately 0.6% nitrogen, 0.4% phosphorus, and 11.5% potassium, making them one of the best natural sources of potassium for flowering and fruiting plants. The Philippines produces over 9 million metric tons of bananas annually, so banana peels are one of the most readily available kitchen scraps for Filipino gardeners.

Ingredients

• 3 to 4 banana peels (any variety - lakatan, latundan, saba)
• 1 liter of water
• A clean jar or container with lid

Process

1. Chop banana peels into small pieces (roughly 2-centimeter squares)
2. Place peels in the jar and cover with 1 liter of water
3. Seal loosely (not airtight) and let soak for 48 hours at room temperature
4. Strain the liquid into a separate container, discarding or composting the peels
5. Dilute the banana tea 1:1 with fresh water before applying

Application

Pour diluted banana peel tea directly onto soil around the base of plants once a week. Best for tomatoes, peppers, eggplant, flowering ornamentals, and fruit-bearing plants. Avoid applying to leafy greens that do not need high potassium.

2. Eggshell Calcium Powder

Eggshells are composed of approximately 95% calcium carbonate - the same compound found in agricultural lime. Calcium strengthens cell walls, prevents blossom end rot in tomatoes and peppers, and helps maintain proper soil pH. A single eggshell contains roughly 2,000 milligrams of calcium.

Ingredients

• 10 to 12 eggshells (rinsed and dried)
• Optional: mortar and pestle or blender

Process

1. Rinse eggshells to remove any egg residue
2. Air-dry shells completely (2 to 3 days) or oven-dry at 100 degrees Celsius for 30 minutes
3. Crush into fine powder using a mortar and pestle, rolling pin, or blender
4. Store in a sealed container. Fine powder releases calcium faster than coarse pieces

Application

Mix 1 tablespoon of eggshell powder into the top 2 inches of soil per pot. Apply once a month. For a faster-acting liquid version, steep 1 tablespoon of powder in 1 liter of water overnight, then use as a soil drench. Best for tomatoes, peppers, eggplant, and any plant showing calcium deficiency (distorted new growth, blossom end rot).

3. Coffee Ground Mix

Used coffee grounds contain approximately 2% nitrogen, 0.3% phosphorus, and 0.3% potassium, along with trace amounts of magnesium, calcium, and copper. They are slightly acidic (pH 6.0 to 6.8 when used), making them beneficial for most vegetable and ornamental plants.

Ingredients

• Used coffee grounds (any variety - barako, instant, or brewed)
• Optional: dried leaves or rice hull for mixing

Process

1. Collect used coffee grounds and spread them on a tray to air-dry for 1 to 2 days
2. Once dry, the grounds can be stored in a sealed container for up to 3 months
3. For direct soil application, mix dried grounds with an equal volume of dried leaves or rice hull to prevent compaction

Application

Spread a thin layer (no more than 1 centimeter) on the soil surface around plants, or mix into the top 2 inches of soil. Apply once a month. Coffee grounds also attract earthworms, which further improve soil health. Do not apply fresh, wet grounds directly - they can form a dense mat that repels water.

4. Fermented Rice Water (FRW)

Rice washing water - the starchy liquid from the first rinse of uncooked rice - is a traditional Filipino plant food that has been used in Philippine farming for generations. When fermented, it becomes rich in lactic acid bacteria (LAB) and beneficial microorganisms that promote healthy soil biology. Fresh rice water contains nitrogen, phosphorus, potassium, and growth-promoting starch.

Ingredients

• Rice washing water from the first rinse (the cloudy, starchy water)
• A clean container with loose-fitting lid

Process

1. Collect the first rinse water when washing rice for cooking (about 500 ml to 1 liter per cup of rice)
2. Pour into a clean container and cover loosely with cloth or a loose lid (not airtight)
3. Let ferment at room temperature for 3 to 5 days. In the Philippine heat, fermentation is faster
4. The water will develop a slightly sour, yogurt-like smell when ready
5. Dilute 1 part fermented rice water to 5 parts fresh water before applying

Application

Apply diluted fermented rice water to soil every 5 to 7 days. Excellent for seedlings, leafy greens, and as a general soil conditioner. The beneficial bacteria help suppress soil-borne diseases and improve nutrient availability. Can also be used as a foliar spray early morning for an additional nutrient boost.

5. Fish Amino Acid (FAA)

Fish amino acid is a potent organic fertilizer made by fermenting fish scraps with brown sugar. It is rich in nitrogen, amino acids, and trace minerals that promote vigorous vegetative growth. FAA is a staple in Korean Natural Farming (KNF) methods, which have gained significant popularity among Filipino organic growers.

Ingredients

• 500 grams of fresh fish scraps (heads, bones, guts - any fish from the palengke)
• 500 grams of brown sugar or muscovado (1:1 ratio by weight)
• A clay pot or plastic container with loose lid

Process

1. Chop fish scraps into small pieces
2. Layer fish and brown sugar alternately in the container, starting and ending with sugar
3. Cover loosely with cloth or a lid that allows gas to escape
4. Store in a shaded, well-ventilated area for 2 to 3 weeks
5. Stir every 2 to 3 days. The mixture will produce a dark, pungent liquid
6. After 2 to 3 weeks, strain the liquid. This is your FAA concentrate
7. Store concentrate in a sealed bottle for up to 12 months

Application

Dilute 1 to 2 tablespoons of FAA concentrate per liter of water. Apply to soil every 2 weeks during the vegetative growth phase. Best for heavy-feeding crops like tomatoes, eggplant, squash, and corn. The strong odor dissipates within 24 hours after soil application. Avoid using on indoor plants due to the smell.

6. Fermented Plant Juice (FPJ)

Fermented plant juice extracts growth hormones and nutrients from young, actively growing plant shoots. The result is a natural growth stimulant that promotes cell division and overall plant vigor. FPJ is another core component of Korean Natural Farming widely used in Philippine organic agriculture.

Ingredients

• 500 grams of young shoot tips from fast-growing plants (kangkong tips, sweet potato shoots, moringa tips, or weed shoots)
• 500 grams of brown sugar or muscovado (1:1 ratio by weight)
• A clay pot or wide-mouth container

Process

1. Collect young shoots early morning before 9 AM when nutrient content is highest
2. Chop shoots into 2 to 3 centimeter pieces without washing (preserve surface microorganisms)
3. Mix thoroughly with brown sugar in a container
4. Press down lightly and cover with breathable cloth
5. Place a weight on top to keep plant material submerged as liquid releases
6. Store in a cool, shaded area for 7 to 10 days
7. Strain the liquid - this is your FPJ concentrate
8. Store in a dark glass bottle for up to 6 months

Application

Dilute 2 tablespoons of FPJ concentrate per liter of water. Apply as a foliar spray or soil drench every 1 to 2 weeks during active growth phases. Particularly effective during transplanting, early vegetative growth, and when plants need a growth boost. Best applied early morning or late afternoon.

7. Compost Tea

Compost tea is a liquid extract of finished compost that concentrates beneficial microorganisms, humic acids, and water-soluble nutrients into an easy-to-apply liquid fertilizer. It is one of the most balanced organic fertilizers you can make at home, providing a full spectrum of macro and micronutrients.

Ingredients

• 1 cup (about 250 grams) of finished, mature compost
• 5 liters of non-chlorinated water (let tap water sit in an open container for 24 hours to dechlorinate)
• Optional: small aquarium air pump for aerated compost tea (ACT)

Process

1. Place compost in a permeable bag (old sock, cheesecloth, or fine mesh) and submerge in 5 liters of water
2. If using an air pump, insert the airstone into the water and run continuously for 24 to 48 hours. Aeration multiplies beneficial microorganisms dramatically
3. If not aerating, stir the mixture vigorously 3 to 4 times daily for 24 to 48 hours
4. Remove the compost bag and use the tea immediately - it begins losing potency within 4 to 6 hours of removing aeration

Application

Apply undiluted directly to soil or use as a foliar spray. For soil application, pour 250 to 500 ml per plant. For foliar spray, apply early morning to both sides of leaves. Compost tea is safe for all plants at all growth stages. Apply weekly for best results.

8. Vermicast Tea

Vermicast tea is made from worm castings (vermicast) and is considered the premium organic liquid fertilizer. Vermicast contains 5 times more nitrogen, 7 times more phosphorus, and 11 times more potassium than regular garden soil, along with beneficial enzymes and growth hormones produced by earthworms during digestion.

Ingredients

• 1 cup (about 250 grams) of vermicast (worm castings)
• 5 liters of non-chlorinated water
• 1 tablespoon of unsulfured molasses (optional - feeds beneficial microbes)

Process

1. Place vermicast in a mesh bag or old stocking
2. Submerge in 5 liters of dechlorinated water
3. Add molasses if using
4. Aerate with an air pump for 24 hours, or stir vigorously several times over 24 hours
5. The tea should look like dark brown coffee when ready
6. Use within 4 to 6 hours for maximum microbial activity

Application

Apply undiluted to soil or as foliar spray. For soil drenching, use 250 to 500 ml per plant weekly. For foliar feeding, spray early morning. Vermicast tea is the most versatile organic fertilizer - safe for seedlings, flowering plants, fruiting crops, and ornamentals at any stage.

Complete Recipe Comparison Table

Use this reference table to choose the right homemade fertilizer based on what your plants need and what kitchen scraps you have available.

Tips for Using Homemade Fertilizers Effectively

• Rotate fertilizer types - Alternate between different recipes weekly to provide a broader range of nutrients. For example, use banana peel tea one week, fermented rice water the next, and compost tea the following week
• Always dilute concentrates - Undiluted FAA and FPJ can burn plant roots. Follow the recommended dilution ratios strictly
• Apply to moist soil - Water plants lightly before applying liquid fertilizers to prevent root shock and improve nutrient absorption
• Apply early morning - Foliar sprays absorb best when stomata (leaf pores) are open, which is typically before 9 AM
• Label and date your containers - Track fermentation times and expiry dates. Most homemade fertilizers lose potency after 3 to 6 months
• Start with half strength - When trying a new recipe, use half the recommended concentration first and observe your plants for 7 days before increasing
• Combine with quality soil - Homemade fertilizers work best in well-structured soil with good drainage and microbial activity

Frequently Asked Questions