Peace Lilies, scientifically known as Spathiphyllum, are cherished indoor plants renowned for their elegant beauty and air-purifying capabilities as studied by NASA. Native to tropical rainforests of Central and South America, these lush, green plants have gained global popularity as beloved household companions. With their glossy leaves and delicate white flowers, Peace Lilies not only add a touch of natural elegance to interior spaces but also offer the practical benefit of being exceptionally tolerant of moderate to low natural light levels, making them a favourite choice for almost any space in the home or office.

Air Purification

Peace Lilies excel at air purification due to their capacity to absorb and break down common indoor air pollutants like formaldehyde and benzene.

Adaptation: Peace Lilies' large leaves offer a generous surface area for gas exchange, while the plant's active rhizomes aid in toxin absorption.

Improved air quality: The result of the air purification process performed by Peace Lilies is an improvement in indoor air quality, making the air cleaner and healthier, and may help those who suffer from allergies and respiratory-related conditions.

Increased ambient humidity: Additionally, Peace Lilies soak up and expel a high volume of moisture through transpiration, increasing environmental humidity and potentially alleviating uncomfortable side effects of dry air such as a dry cough or dry and irritated skin.

Preferred Growing Conditions

On average, a mature Peace Lily can reach a height of 30- 120cm when grown indoors, spreading out to around 80cm. However, taller specimens like the Spathiphyllum Sensation are common and when they receive ample light and care can reach upwards of 190cm and produce foliage that is well over 100cm in width.

Light: Peace Lilies flourish in environments with ample moderate to low indirect light. Their adaptation has enabled them to survive overshadowed by larger forest flora. This gives Peace Lilies a unique ability to efficiently produce photosynthesis even with low natural lighting. As a consequence, their leaves are thin and delicate in comparison to other popular indoor plants, and can easily dry up and burn when exposed to bright, direct sunlight. 

Temperature: Their sweet spot resides within the 18-27°C range, rendering them perfectly suited for the typical indoor climates all year round. However, avoid placing Peace Lilies in areas that drastically fluctuate in temperature like draughty doorways and consistently used heating and cooling units and vents.

Humidity: Peace Lilies relish elevated humidity levels anywhere above 50%. However, they are hardy and adaptable and can endure indoor humidity levels as low as 30%-40% which is about the normal humidity range for most temperate indoor environments.

Soil: Choose a premium-grade potting soil. A typical potting mix should consist of equal parts peat-based potting mix, perlite, and organic matter. It's essential to ensure that the potting mix is well-balanced for water retention, well-draining, and not too dense for adequate aeration of the roots.

Pot Size: Opt for containers that allow for growth but avoid overly spacious pots, as Peace Lilies thrive when slightly root-bound. Choose a pot that is around 5cm wider and deeper than the original or nursery pot. Peace Lilies are moderate growers and the length of time between repotting will depend on the growing conditions.

Indoor Care Tips

The most crucial aspect of caring for a Peace Lily (Spathiphyllum) is maintaining consistent soil moisture. Being native to tropical rainforests, these plants thrive when their soil is consistently moist and is extremely sensitive to dry conditions.

Watering: To maintain consistent soil moisture without inducing waterlogging, it's best to let the top inch of soil dry before watering anew. Peace Lilies provide a visual cue when thirsty, as their leaves droop, signalling the need for hydration.

Fertilisation: Sustain their vibrancy by providing balanced liquid fertiliser every 6 weeks during the active growing season (spring through to early autumn). Stop fertilising in the “resting phase” (late autumn and winter) as Peace Lilies naturally slow foliage production and additional nutrients are not required until the next growing season.

Pruning: Pruning Peace Lilies is vital for maintaining its appearance by removing unattractive spent flowers and yellow foliage. It also helps prevent diseases like mould and bacterial growth by improving air circulation and reducing density. In addition, it controls the size of the plant for indoor suitability and encourages new foliage growth and flowering in the growing season.

Division propagation: To propagate a Peace Lily, gently divide the mature plant early in the growing season. Separate it into smaller sections, ensuring each has roots and leaves. Plant these sections in fresh potting mix in a new pot, water thoroughly, and place in bright, indirect light, continuing regular care for healthy growth.

Problems and Solutions

Yellow leaves: This usually occurs from underwatering or insufficient sunlight. Adjust the watering frequency to ensure that the water is reaching all the way down to the roots. The best way of checking this is to poke your finger into the soil about an hour after watering. If the subsoil is still dry, increase the volume of water. Move your Peace Lily plant to a brighter position or install UV grow lights that will increase the plant’s surface area exposure to light.

Brown Leaf Tips: Low humidity or watering has a high concentration of chlorine. Increase humidity by clustering your indoor plants closer together or mist your Peace Lily plant regularly. To decrease chlorine, use filtered water or temporarily move your plants outdoors on rainy days. Only do this if the pot has drainage holes to prevent waterlogging.

Failure to flower: There are several reasons why Peace Lilies may not flower. Younger Peace Lilies may not bloom as prolifically as mature plants. They often require several years to reach their full flowering potential. Insufficient light may hinder their flowering potential. Most spring and summer-growing plants require a higher concentration of UV light for photosynthesis. However, be mindful that overexposure to sunlight is detrimental. Also, using a high-nitrogen fertiliser can promote lush foliage growth at the expense of flowers. Use a balanced, diluted fertiliser and follow recommended application rates.

Pests: Although relatively hardy, Peace Lillies can become susceptible to pests and diseases with weakened defences due to significant underwatering. Common indoor pests like spider mites or aphids should be treated with neem oil or insecticidal soap. Gently wipe the leaves with a damp cloth to physically remove dead or resilient pests. This will also unclog the pores for optimal carbon absorption and air filtration.

Cultivating Peace Lilies indoors not only introduces a touch of tropical allure to your living spaces but also bestows the gift of cleaner air. With their adaptability to indoor conditions and straightforward care needs, this abundant foliage-producing, flowering perennial will cater to both novice and seasoned indoor gardeners for many years to come.