Fertilizer and care for indoor plants: the complete guide to feeding your plants naturally

Why fertilize your indoor plants?

Unlike outdoor plants that draw nutrients from rich, replenished soil, your indoor plants live in a limited space. The potting soil gradually loses nutrients, and watering washes away essential minerals. Fertilizing provides your plants with the nutrients they need to grow, bloom, and stay healthy.

The three main nutrients (NPK)

When to fertilize your indoor plants?

The fertilization calendar

Spring and summer (March to September): active growth period. Fertilize every 2 to 4 weeks depending on the plant and fertilizer type.

Autumn and winter (October to February): period of vegetative rest. Reduce or stop fertilizing. Most plants don’t need any fertilizer during this time, except tropical plants with continuous growth.

Signs your plant needs fertilizer

• Slow or stagnant growth
• Pale or yellowing leaves (especially the older ones)
• Weak and elongated stems
• No flowering despite the season being favorable
• Leaves smaller than usual

Different types of fertilizers for indoor plants

1. Liquid fertilizers

Advantages: fast absorption, precise dosing, ideal for the growing season.
Use: dilute in watering water according to instructions (usually 1 cap per 1L of water).
Frequency: every 2 weeks during the growing season.

2. Granular or stick fertilizers

Advantages: slow release, convenient, less risk of overdosing.
Use: push into the soil; the fertilizer releases with each watering.
Frequency: renew every 2-3 months.

3. Organic and natural fertilizers

Advantages: environmentally friendly, also nourish the soil, slow release.
Examples: compost, worm castings, plant teas, seaweed-based fertilizers.

4. Specialized fertilizers

Some plants have specific needs:

How to fertilize without burning the roots?

Over-fertilization is one of the most common mistakes with indoor plants. Here’s how to avoid it:

Golden Rules of Fertilizing

• Always dilute: strictly follow the recommended dosages, or even halve them to start
• Water before fertilizing: never apply fertilizer to dry soil, as it will burn the roots
• Less is more: it’s better to under-fertilize than over-fertilize
• No fertilizer after repotting: the new soil already contains nutrients. Wait 6-8 weeks before fertilizing
• Stop if the plant is stressed: a sick, dormant, or recently moved plant should not be fertilized

Signs of over-fertilization

• White deposits or crust on the soil surface
• Burnt leaf tips and edges (brown and dry)
• Wilting despite regular watering
• Distorted or excessive growth

5 Homemade Natural Fertilizer Recipes

Economical and eco-friendly, these DIY fertilizers are perfect for naturally nourishing your plants:

1. Coffee Grounds

Rich in nitrogen, ideal for green plants like Monstera, Ficus, or Calathea.
Usage: sprinkle a thin layer of dried grounds on the soil surface (1 teaspoon per pot), or dilute in watering water (1 cup of grounds per 1L of water, let infuse for 24 hours).

2. Cooking water

Rich in minerals (vegetables, eggs, pasta).
Usage: let cool completely, use unsalted, water once a month.

3. Banana peels

Rich in potassium, excellent for flowering.
Usage: break into pieces and bury in potting soil, or soak in water for 48 hours and use the water for watering.

4. Eggshells

Rich in calcium, strengthens cell walls.
Usage: crush finely and mix into potting soil during repotting, or sprinkle on the surface.

5. Compost tea or infusion

Complete fertilizer, rich in nutrients and beneficial microorganisms.
Usage: soak compost in water (1 part compost to 5 parts water) for 24-48 hours, strain, and use for watering.

In summary: keys to successful fertilizing

• Fertilize only during the growing season (spring-summer)
• Follow dosage instructions and favor under-fertilizing
• Always water before fertilizing
• Adjust fertilizer to each plant’s needs
• Watch your plants: they’ll tell you if they’re hungry or if it’s too much
• Combine commercial fertilizers and natural solutions for optimal balance

Fertilizing is a key pillar of indoor plant care, just like watering, light, and repotting. By following these tips, you’ll give your plants everything they need to thrive all year long. 🌿

Complete your plant care routine

Now that you’ve mastered fertilizing, explore our other essential guides to care for your indoor plants and provide the best growth conditions.

Our essential care guides:

✅ Practical and detailed guides
✅ Advice based on hands-on experience
✅ Tips for all levels

Mini FAQ

Can I use coffee grounds as fertilizer for all my plants?

Coffee grounds are rich in nitrogen and are especially suitable for leafy green plants like Monstera, Ficus, or Calathea. However, they are slightly acidic and not suitable for all plants: avoid using them for cacti, succulents, and plants that prefer neutral or alkaline soil. Use sparingly (maximum 1 teaspoon per pot).

Care guide

Fertilization

Natural fertilizers

DIY

Unlike outdoor plants, your indoor plants live in a limited space where the potting soil gradually loses nutrients. Discover when, how, and with what to fertilize them for optimal growth, with 5 homemade natural fertilizer recipes and a fertilization calendar adapted to each season.

Why fertilize your indoor plants?

Unlike outdoor plants that draw nutrients from rich, replenished soil, your indoor plants live in a limited space. The potting soil gradually loses nutrients, and watering washes away essential minerals. Fertilizing provides your plants with the nutrients they need to grow, bloom, and stay healthy.

The three main nutrients (NPK)

Nutrient	Symbol	Main role	Deficiency signs
Nitrogen	N	Promotes leaf and stem growth	Older leaves yellowing, slow growth
Phosphorus	P	Stimulates root development and flowering	Dark green or purplish leaves, no flowering
Potassium	K	Strengthens disease resistance and overall vigor	Yellowed or burnt leaf edges, weak stems

⚠️ Warning

Without regular feeding, your plants may show deficiency signs: yellowing leaves, slow growth, no flowering. But beware, these symptoms can also indicate other issues like improper watering or lack of light.

When to fertilize your indoor plants?

The fertilization calendar

Spring and summer (March to September): active growth period. Fertilize every 2 to 4 weeks depending on the plant and fertilizer type.

Autumn and winter (October to February): period of vegetative rest. Reduce or stop fertilizing. Most plants don’t need any fertilizer during this time, except tropical plants with continuous growth.

💡 Tip

Check out our month-by-month care calendar to adjust fertilization to your plants' cycle and discover all the seasonal care tips.

Signs your plant needs fertilizer

• Slow or stagnant growth
• Pale or yellowing leaves (especially the older ones)
• Weak and elongated stems
• No flowering despite the season being favorable
• Leaves smaller than usual

Different types of fertilizers for indoor plants

1. Liquid fertilizers

Advantages: fast absorption, precise dosing, ideal for the growing season.
Use: dilute in watering water according to instructions (usually 1 cap per 1L of water).
Frequency: every 2 weeks during the growing season.

2. Granular or stick fertilizers

Advantages: slow release, convenient, less risk of overdosing.
Use: push into the soil; the fertilizer releases with each watering.
Frequency: renew every 2-3 months.

3. Organic and natural fertilizers

Advantages: environmentally friendly, also nourish the soil, slow release.
Examples: compost, worm castings, plant teas, seaweed-based fertilizers.

4. Specialized fertilizers

Some plants have specific needs:

Plant type	Recommended fertilizer	Examples
Flowering plants	Rich in phosphorus (P)	Orchids, Anthurium, Spathiphyllum
Green plants	Rich in nitrogen (N)	Monstera, Ficus, Calathea
Cacti and succulents	Diluted fertilizer, low in nitrogen	Cactus, Aloe, Echeveria
Orchids	Special orchid fertilizer	Phalaenopsis, Dendrobium

How to fertilize without burning the roots?

Over-fertilization is one of the most common mistakes with indoor plants. Here’s how to avoid it:

Golden Rules of Fertilizing

• Always dilute: strictly follow the recommended dosages, or even halve them to start
• Water before fertilizing: never apply fertilizer to dry soil, as it will burn the roots
• Less is more: it’s better to under-fertilize than over-fertilize
• No fertilizer after repotting: the new soil already contains nutrients. Wait 6-8 weeks before fertilizing
• Stop if the plant is stressed: a sick, dormant, or recently moved plant should not be fertilized

Signs of over-fertilization

• White deposits or crust on the soil surface
• Burnt leaf tips and edges (brown and dry)
• Wilting despite regular watering
• Distorted or excessive growth

💧 Emergency Solution

If you notice these symptoms, rinse the soil thoroughly with clear water to remove excess mineral salts, or repot in fresh soil.

5 Homemade Natural Fertilizer Recipes

Economical and eco-friendly, these DIY fertilizers are perfect for naturally nourishing your plants:

1. Coffee Grounds

Rich in nitrogen, ideal for green plants like Monstera, Ficus, or Calathea.
Usage: sprinkle a thin layer of dried grounds on the soil surface (1 teaspoon per pot), or dilute in watering water (1 cup of grounds per 1L of water, let infuse for 24 hours).

2. Cooking water

Rich in minerals (vegetables, eggs, pasta).
Usage: let cool completely, use unsalted, water once a month.

3. Banana peels

Rich in potassium, excellent for flowering.
Usage: break into pieces and bury in potting soil, or soak in water for 48 hours and use the water for watering.

4. Eggshells

Rich in calcium, strengthens cell walls.
Usage: crush finely and mix into potting soil during repotting, or sprinkle on the surface.

5. Compost tea or infusion

Complete fertilizer, rich in nutrients and beneficial microorganisms.
Usage: soak compost in water (1 part compost to 5 parts water) for 24-48 hours, strain, and use for watering.

⚠️ Important

Homemade fertilizers are less concentrated and less balanced than commercial ones. They’re perfect as a supplement but may not be enough for very hungry plants. For best results, combine them with a balanced commercial fertilizer.

In summary: keys to successful fertilizing

• Fertilize only during the growing season (spring-summer)
• Follow dosage instructions and favor under-fertilizing
• Always water before fertilizing
• Adjust fertilizer to each plant’s needs
• Watch your plants: they’ll tell you if they’re hungry or if it’s too much
• Combine commercial fertilizers and natural solutions for optimal balance

Fertilizing is a key pillar of indoor plant care, just like watering, light, and repotting. By following these tips, you’ll give your plants everything they need to thrive all year long. 🌿

Complete your plant care routine

Now that you’ve mastered fertilizing, explore our other essential guides to care for your indoor plants and provide the best growth conditions.

🌿 Additional guides

Fertilizing is just one aspect of care. Discover our guides for a complete approach and healthy plants all year round.

Our essential care guides:

Watering guide Repotting guide Month-by-month calendar

10 mistakes to avoid Plants in winter Easy-care plants

✅ Practical and detailed guides
✅ Advice based on hands-on experience
✅ Tips for all levels

Mini FAQ

What is the best time to fertilize my indoor plants?

The best time to fertilize your indoor plants is spring and summer (March to September), when they are actively growing. During this period, fertilize every 2 to 4 weeks with diluted liquid fertilizer, or every 2-3 months with slow-release sticks. In autumn and winter, most plants go dormant and don’t need fertilizer, except tropical plants that continue growing. Check our month-by-month care calendar to adjust fertilization to your plants’ cycle.

How can I tell if my plant needs fertilizer?

Several signs indicate a plant is lacking nutrients: slowed or stagnant growth, pale or yellowing leaves (especially older ones), weak and elongated stems, no flowering despite the right season, and smaller leaves than usual. If you notice these symptoms and haven’t fertilized for several months, it’s time to add nutrients. However, be careful not to confuse nutrient deficiency with other issues like improper watering or lack of light.

What is the difference between liquid fertilizer and granular fertilizer?

Liquid fertilizer is diluted in watering water and quickly absorbed by the roots, making it ideal for the growing season with applications every 2 weeks. It allows precise dosing but requires regular application. Granular or stick fertilizers are placed directly in the soil and gradually release nutrients with each watering over 2-3 months, which is more convenient and reduces the risk of overdosing. The choice depends on your preference: liquid for precise control, granular for simplicity and slow release.

Can I use coffee grounds as fertilizer for all my plants?

Coffee grounds are rich in nitrogen and are especially suitable for leafy green plants like Monstera, Ficus, or Calathea. However, they are slightly acidic and not suitable for all plants: avoid using them for cacti, succulents, and plants that prefer neutral or alkaline soil. Use sparingly (maximum 1 teaspoon per pot).