Peace lilies are popular houseplants, known for their elegant white “flowers” that contrast with dark green foliage. These white structures can surprisingly turn green, a common observation that raises questions about its cause and implications. This article explores the botanical nature of these “flowers,” reasons for their greening, and how to encourage bright white blooms.
Understanding Peace Lily Spathes
The prominent white part of a peace lily, often considered a flower, is not a true flower. It is a modified leaf called a spathe. This specialized leaf encloses the actual tiny flowers, found on a central, finger-like stalk known as a spadix. Spathes attract pollinators and protect the delicate true flowers. As a modified leaf, a spathe contains chlorophyll, the green pigment for photosynthesis, explaining why it can turn green by producing more pigment.
Common Reasons for Greening Spathes
Spathes naturally cycle through colors. They typically emerge with a greenish tint, transition to bright white during peak bloom, and then revert to green as they age and their role in pollination concludes. This natural aging allows the spathe to produce chlorophyll, contributing to the plant’s energy production like a regular leaf. Observing a mature spathe turning green is often a sign of this normal progression.
Light exposure significantly influences spathe coloration. Peace lilies thrive in bright, indirect light, mimicking their natural forest floor habitat. Too much direct sunlight can cause the spathe to produce more chlorophyll as a protective measure, leading to premature greening. Conversely, insufficient light also results in greening, as the plant attempts to maximize light absorption through increased chlorophyll production in existing spathes.
Nutrient balance in the soil can indirectly affect spathe color. An excess of certain nutrients, particularly nitrogen, can encourage lush foliage growth at the expense of white blooms and contribute to spathes turning green. Nitrogen promotes chlorophyll synthesis, and over-fertilization can disrupt plant processes. Phosphorus plays a role in flower production, and a deficiency could hinder the development or maintenance of white coloration.
Encouraging White Blooms and Overall Plant Health
Adjusting light conditions effectively promotes vibrant white spathes. Peace lilies flourish in bright, indirect light, like that from an east or north-facing window. If direct sunlight is unavoidable, a sheer curtain can diffuse intensity, preventing leaf scorching and premature spathe greening. Consistent light, rather than frequent location changes, helps the plant maintain energy balance for blooming.
Pruning spent spathes encourages new, white blooms. Once a spathe turns green or brown and its natural cycle is complete, remove it. Cut the flower stalk as close to the plant’s base as possible, using clean, sharp shears. This redirects the plant’s energy from maintaining the aging spathe to developing new growth and fresh white structures.
Appropriate fertilization supports healthy growth and consistent blooming. Peace lilies benefit from a balanced liquid houseplant fertilizer, applied at half or quarter strength during the growing season (spring and summer). Avoid over-fertilizing, as it can lead to spathe greening. Fertilizing every 6 to 8 weeks is sufficient.
Beyond light and nutrients, general care contributes to overall plant vigor and blooming. Consistent watering, allowing the top inch of soil to dry before rewatering, prevents stress. Peace lilies appreciate moderate to high humidity; misting the foliage or placing the pot on a pebble tray helps. Regularly wiping dust from leaves also improves the plant’s ability to photosynthesize.