Peace lilies are popular houseplants, appreciated for their lush green foliage and distinctive white blooms. Though low-maintenance, providing appropriate nutrients through fertilization enhances growth and encourages abundant flowering. These plants are not heavy feeders, so they do not require frequent or strong fertilizer applications.
Why and When to Fertilize Peace Lilies
Fertilizing peace lilies replenishes essential soil nutrients, depleted by watering and plant uptake. This supports vigorous foliage and encourages their white spathes, often mistaken for flowers. Signs a peace lily needs fertilization include slowed growth, lack of new blooms, or pale, off-color leaves.
The best time to fertilize peace lilies is during their active growing season, spring through summer. Increased daylight and warmer temperatures stimulate growth, allowing nutrient absorption. Reduce or cease fertilization during fall and winter, as growth slows and the plant enters dormancy. Fertilizing then can lead to nutrient buildup, potentially harming the plant.
Choosing the Right Fertilizer
Understanding NPK Ratios
Fertilizers are labeled with three numbers: Nitrogen (N), Phosphorus (P), and Potassium (K) (NPK). Nitrogen promotes lush leaf and stem growth, chlorophyll production, and plant vigor. Phosphorus supports root development, energy transfer, and encourages flower and fruit production. Potassium assists cellular functions, regulates water movement, improves disease resistance, and contributes to plant strength.
For peace lilies, a balanced fertilizer like 20-20-20 or 10-10-10 is recommended. This ratio ensures a steady supply of all three macronutrients for health. A fertilizer with slightly higher nitrogen can support foliage growth, or a bloom-focused formula can encourage more flowering. However, avoid excessively high nitrogen formulas, as this prioritizes leafy growth over flower production.
Liquid and Slow-Release Options
Both liquid and slow-release fertilizers are available. Liquid fertilizers provide immediate nutrient availability to roots, acting fast and allowing quick adjustments. They are easy to dilute, a key advantage for peace lilies sensitive to over-fertilization. However, they require more frequent application.
Slow-release fertilizers (granular or pellet) release nutrients gradually. This offers convenience, requiring fewer applications. While beneficial for consistent feeding, dosage control is less precise than liquid forms, and temperature can influence release rate. For potted indoor plants, organic slow-release fertilizers are recommended to mitigate nutrient buildup.
Exploring Organic Fertilizers
Organic options provide nutrients, supporting soil health. Vermicompost tea, from worm castings, is rich in nutrients for healthy root and leaf growth. Seaweed liquid fertilizer, another organic choice, is quickly absorbed, providing natural nutrients, plant hormones, and micronutrients that stimulate bud formation. These solutions are gentler, reducing over-fertilization risk.
Coffee grounds and banana peels can be used. Coffee grounds contain nitrogen, beneficial for leaf growth, and can be added to compost. Banana peels are a source of potassium, also incorporated into compost. Epsom salt (magnesium sulfate) provides magnesium for chlorophyll production. It is advised to add these to compost rather than directly to the soil to ensure proper nutrient release and avoid issues.
How to Fertilize Peace Lilies
Proper Dilution and Application
Peace lilies are sensitive to concentrated fertilizers, so proper dilution of liquid formulas is essential to prevent root burn. Dilute liquid fertilizers to half or even one-quarter of the strength suggested on the product label. Before applying, water the peace lily thoroughly. Applying fertilizer to moist soil ensures better nutrient absorption and even distribution. Pour the diluted solution directly onto the soil, avoiding contact with leaves.
For slow-release pellets, follow product instructions for incorporation. Some products broadcast on the soil surface, while others mix into the top potting mix layer. Always ensure proper drainage to prevent waterlogging, especially when drenching the soil.
Fertilizing Frequency
Fertilization frequency depends on fertilizer type and growing conditions. For liquid fertilizers, a guideline is to fertilize every four to six weeks during spring and summer. Organic options like vermicompost tea may require less frequent applications, every 45 to 60 days.
Peace lilies in lower light require less frequent fertilization, perhaps once or twice a year, due to slower nutrient uptake. Plants in brighter, indirect light may benefit from more regular feeding due to increased energy production and nutrient demand. Monitor for signs of nutrient deficiency or excess, and adjust frequency accordingly.
Avoiding Common Fertilizing Mistakes and Problems
Over-fertilization is a common issue that can harm peace lilies. Signs (nutrient burn or fertilizer burn) include brown edges, crispy leaf tips, or general yellowing or browning of leaves shortly after application. This damage occurs because excess fertilizer salts draw moisture from roots, hindering water absorption and leading to dehydration. Over-fertilizing can also stunt growth or interfere with soil pH.
If signs of over-fertilization appear, act quickly. “Leach” or “flush” the soil by placing the potted plant under running water for several minutes, allowing excess fertilizer salts to drain through the pot’s drainage holes. This washes away accumulated nutrients. Repotting with fresh soil can be beneficial in severe mineral salt stress cases.
Peace lilies are sensitive to fluoride, a chemical found in tap water, which can cause brown leaf tips. While not a direct fertilizing mistake, it can be mistaken for nutrient burn. Using filtered water, rainwater, or allowing tap water to sit overnight to dissipate chemicals mitigates fluoride sensitivity.