Houseplant
Peace Lily
Spathiphyllum wallisii · Araceae
Also called: Spath, White Sails, Mauna Loa (cultivar name), Closet Plant
Peace Lily (Spathiphyllum wallisii) is a moderate-water houseplant well suited to Tucson and the low desert. It's a moderate-growing houseplant.
Peace Lily at a glance
- Water use
- Moderate (established)
- Sun
- Medium to bright indirect light indoors; tolerates low light but blooms best in bright indirect light. Avoid direct desert sun, which scorches and yellows leaves.
- Mature size
- 1-3 ft tall and wide indoors depending on cultivar.
- Growth rate
- Moderate
- Bloom
- White (a hooded white spathe surrounding a creamy spadix), Mainly spring, often reblooming sporadically through the year in good light.
- Cold hardiness
- Frost-tender; keep above ~55F. Grown indoors in Tucson. Min comfortable indoor temp ~55-60F.
- Soil
- Rich, well-draining peat-based potting mix that holds some moisture; slightly acidic.
- Native range
- Tropical Americas (Colombia, Venezuela, Central America)
- Best used as
- Indoor decor/flowering houseplant, Low-light tolerant plant, Air-purifying houseplant, Office/interior plant
- Wildlife
- None indoors.
- Toxicity
- Toxic to cats, dogs, and humans; contains insoluble calcium oxalate crystals causing oral/throat burning, drooling, and swelling if chewed. Keep from pets and children.
How to grow Peace Lily in Tucson & the low desert
Watering
Keep soil consistently lightly moist, watering when the top inch dries, roughly every 5-7 days. It dramatically wilts when thirsty and recovers after watering. In Tucson's dry air it dries quickly and leaf tips brown easily, so maintain humidity (pebble tray/humidifier) and ideally use filtered or rainwater, since it is sensitive to chlorine, fluoride, and the salts in Tucson's hard tap water.
Fertilizer & nutrients
Light to moderate feeder; balanced houseplant fertilizer at half strength every 6-8 weeks in spring/summer. Over-fertilizing causes brown leaf tips; flush soil periodically to remove salt buildup, important with Tucson's mineral-rich water.
Pruning & care
Remove spent flower stalks at the base and trim yellow or brown-tipped leaves. Divide overcrowded clumps in spring to propagate.
Notes
Grown indoors in Tucson; not frost-hardy. Its two big Tucson challenges are low humidity and hard, chlorinated/fluoridated tap water, both of which cause the classic brown leaf tips, so use filtered/rainwater and boost humidity. A reliable bloomer and excellent low-light air purifier. Drooping leaves are a quick visual cue that it needs water.
Sources: University of Arizona Cooperative Extension (Pima County Master Gardeners) houseplant guidance; Missouri Botanical Garden Plant Finder; ASPCA Toxic and Non-Toxic Plant List; NASA Clean Air Study