The peace lily (Spathiphyllum) is a popular houseplant known for its elegant white “blooms.” These distinctive white structures often turn green, which is a common and usually harmless phenomenon. Understanding why this happens can help maintain the plant’s appearance.
The Peace Lily “Flower” Unveiled
What many people refer to as the peace lily’s flower is actually a specialized leaf structure called a spathe. This prominent, often boat-shaped, white or off-white part serves to attract pollinators. The actual tiny flowers are clustered on the central, finger-like spike, which is known as the spadix. A healthy, newly emerged spathe typically displays a pristine white or creamy hue, providing a striking contrast against the plant’s deep green foliage.
Common Causes of Green Spathes
As the peace lily’s spathes mature, a natural physiological process often leads to their color change.
Natural Maturation
Over time, the cells within the spathe begin to produce chlorophyll, the green pigment found in leaves responsible for photosynthesis. This maturation process allows the aging spathe to contribute to the plant’s overall energy production, much like a regular leaf. The gradual shift from white to green is a normal part of the spathe’s life cycle, indicating it has completed its primary function of attracting pollinators.
Light Imbalance
The amount of light a peace lily receives significantly influences the color development of its spathes. If a peace lily is exposed to excessively bright or direct light, the spathe may produce more chlorophyll as a protective mechanism against intense sun, causing it to green prematurely. Conversely, insufficient light can also contribute to greening, as the plant may not have enough energy to produce the vibrant white pigment, leading to less developed or paler spathes that retain a greenish tint.
Nutrient Overload
Nitrogen is a nutrient that primarily promotes lush, green vegetative growth in plants. When a peace lily receives too much nitrogen, it prioritizes leaf and stem development over flower production, often resulting in fewer blooms or spathes that appear greener. A balanced nutrient regimen is important for encouraging the desired white spathes.
Genetics and Variety
The genetic makeup of individual peace lily varieties plays a role in their inherent tendency to produce green-tinted spathes. Some cultivars are naturally predisposed to having spathes with a slight green hue, or they may green more readily than others. For instance, certain dwarf varieties or those with specific hybrid origins might exhibit a more persistent green coloration from an early stage, which is simply a characteristic of that particular plant type.
Solutions and Strategies for Whiter Blooms
Adjusting the plant’s environmental conditions can often encourage the development and retention of pristine white spathes.
Light
Peace lilies thrive in bright, indirect light. Position the plant a few feet from a north or east-facing window, or use a sheer curtain for brighter windows. This diffused illumination prevents both light-induced greening and insufficient pigment production, helping the plant produce consistently white spathes.
Fertilization
Adjusting fertilization practices can also impact spathe color. Use a balanced liquid fertilizer (e.g., 20-20-20) every 4-6 weeks during the growing season. Reducing nitrogen-heavy fertilizers encourages bloom development over foliage, promoting whiter spathes. Always dilute fertilizer to half strength to prevent nutrient burn.
Pruning
Pruning aged, greening spathes stimulates new, fresh white ones. Once a spathe greens or declines, cut it back at its base. This redirects the plant’s energy from older structures to new growth, including new white spathes, and improves overall appearance.
General Care
Consistent general care, including proper watering and humidity, contributes to the plant’s vigor and blooming potential. Peace lilies prefer consistently moist, not waterlogged, soil and benefit from higher humidity. A healthy plant is more likely to produce robust, white spathes.
Is a Green Spathe a Problem?
Green spathes on a peace lily are generally not a sign of a sick or dying plant. This color change is often natural or a response to environmental factors. While pure white spathes are preferred aesthetically, green spathes do not harm the plant’s overall health or ability to thrive. The plant continues to photosynthesize and grow.