Peace Lily (Spathiphyllum) – The Complete Guide

With its small, spoonlike flowers, the peace lily (Spathiphyllum) is often confused with the usually red-flowered flamingo flower (Anthurium), although they are two different species.

However, like the other, one is an easy-to-care-for houseplant that enjoys great popularity in many living rooms. Another common name for the peace lily is spath.

Origin and Distribution

Spathiphyllum is not a single species, but a genus of plants with about 50 different species within the arum family (Araceae). Also, other popular plants like the arum lily, the calla, or the flamingo flower belong to this family.

Most of these peace lily varieties are native to the tropical regions of South America, with many originating from Colombia, and to date have not been scientifically described.

In its natural environment, the peace lily thrives in the shade of the large jungle trees.

Use

Several of the approximately 50 species of monocots are cultivated as ornamental or houseplants. The white-flowered Spathiphyllum floribundum and Spathiphyllum patinii and the species Spathiphyllum wallisii, with its rapidly greening petals, are especially important.

In addition, a number of special hybrids exist. However, the plant, which originates from tropical regions, is not suitable for keeping in the garden. But you can place it in a shady spot on the balcony or terrace during the warm summer months.

Appearance and Growth

All Spathiphyllum species are herbaceous plants that grow between 12 and 48 inches (30 and 120 cm) high, as well as densely caespitose.

The species is perennial and, with good care, can live for many years to even decades. Within that time it can reach a handsome size and girth.

Over the years, it also develops a strong rootstock. The peace lily has a rhizome that develops just below the substrate surface. Sometimes you can even see it on the surface.

The leaves sprout directly from the rhizome. The species does not carry milky sap, which is otherwise typical for many arum plants.

Leaves

The most striking thing about the peace lily is probably its large, glossy green and metallic shimmering foliage leaves.

These grow to about 10 inches (25 cm) long and are long-stalked. They have an elliptical to elongated shape with a distinct, triangular midrib.

Spathiphyllum also owes its name to its attractive foliage: The Greek-derived word spatha refers to spoon-shaped tools such as a spatula or spade, an oar blade, or even a sword.

The second part of the botanical name, phýllon, which is also Greek, simply means leaf. The genus belongs to the botanical order of Alismatales.

However, the large leaves can do more than just look beautiful. Just like the snake plant (Sansevieria), the peace lily is considered an excellent indoor air purifier.

It can filter out potentially toxic components such as formaldehyde, benzene, ammonia, and others. For this reason, it is recommended to put Spathiphyllum in bedrooms.

Flowers and Flowering Time

The peace lily forms long-stalked, yellowish flower bulbs, usually between March and September. These flower bulbs are enclosed in white to greenish-colored bracts.

In winter, on the other hand, new flowers usually do not develop.

Some species and cultivars also emit a slight scent of vanilla when in bloom. The flowers persist for several weeks, but change color over time from bright white to greenish.

What to Do if Your Peace Lily Does Not Bloom

If the peace lily does not want to bloom, various causes come into question. The most common reasons are a too dark location and/or wrong watering or fertilizing.

Although the species thrives very well in the shade, it needs brightness for the formation of flowers. But direct sunlight might also be too much for the plant.

In addition, you should fertilize the highly nutritious plant regularly and not water it with cold water straight from the tap.

If the best care does not help, which can often be the case with older specimens, the following measure will help.

Place the peace lily in a cool place for a few months over the winter. An unheated or little heated bedroom will do well. Stop fertilizing the plant and water it only a little.

After at least eight weeks, water the plant thoroughly and fertilize vigorously with good flowering plant fertilizer. After that, it should sprout numerous new flowers.

Fruits

The peace lily usually does not form fruits in indoor culture due to the lack of pollination. In its natural habitat, green berries develop after flowering and contain up to eight tiny seeds.

Toxicity

The peace lily is toxic to both humans and animals. Therefore, you should not place it in households with small children and/or pets like cats, dogs, small rodents, and birds. Or at least place it out of their reach.

A possible poisoning with Spathiphyllum manifests itself among other things by increased salivation, swallowing difficulties, nausea, vomiting, and diarrhea.

Furthermore, Spathiphyllum is considered allergenic, with the flowers and pollen, in particular, being allergens.

Which Location is Suitable for Peace Lily?

As in its natural habitat in the tropical rainforest, the peace lily thrives best in a bright, semi-shaded place without direct sunlight. It favors high humidity and temperatures between 64 and 77 °F (18 and 25 °C).

But also shadier places, for example at a north window, work well for the plant. However, in a darker place the plant forms many dark green leaves, but hardly any flowers.

In locations that are too sunny, on the other hand, there is a risk of sunburn, which manifests itself primarily in leaf edge damage. Especially during the flowering period, Spathiphyllum is quite sensitive to the sun.

The plants feel most comfortable in a bright bathroom due to the permanently higher humidity.

However, it must not get colder than about 64 °F (15 °C), even in winter.

Substrate

For the substrate, use high-quality, normal potting soil, preferably compost-based and without cheap peat. Mix it with expanded clay or clay granules for better permeability.

Alternatively, you can mix the planting soil yourself from compost, leaf soil, and sand in equal parts.

Make sure that the basic materials are free of pathogens such as fungi and do not contain germinable weed seeds. For this reason, disinfect the mixed substrate in the oven or microwave.

Planting and Repotting Peace Lily

The peace lily does not need an overly large plant pot. But it is rather recommended to repot it annually into a larger container because of its rapid growth.

However, since it stops growing at a certain height, which varies depending on the species and variety, the last plant pot should eventually be no larger than about 8 inches (20 cm) in diameter.

When the plant is fully grown, you only need to replace the old substrate with a fresh one about every two to three years.

But whether planting or repotting, it is important in any case to have good drainage in the planter. The container definitely needs a drain through which excess irrigation water can flow away unimpeded.

Cover the drainage hole at the bottom of the pot with larger shards of clay to prevent silting and thus clogging.

Hydroponics

You create perfect conditions for the peace lily if you keep it in hydroponics. The plant is very suitable for this form of indoor plant culture, especially since then you do not have to worry about regular watering and fertilizing.

Preferably use special pots with a water level indicator and only choose fertilizers suitable for hydroponics. These are composed and prepared differently than conventional fertilizers for plants kept in soil culture.

Watering Peace Lily

As a typical rainforest plant, the peace lily needs a lot of moisture. But it should also never be permanently wet.

Waterlogging inevitably leads to root rot and thus to the death of the houseplant. Although wet roots do no harm for a short time, you should always promptly remove excess water from the planter or saucer.

Keep the peace lily evenly moist, and only water it again when the substrate surface has already dried slightly.

During the winter months, Spathiphyllum usually needs less water. At least as long as you place it in a slightly cooler place and not necessarily directly next to or above a heater.

Also primarily during the winter months, make sure the humidity is high. It is a good idea to spray the monocot regularly all around with a sprayer. The plant also enjoys an occasional hand-warm shower.

Fertilizing Peace Lily Properly

Since Spathiphyllum, like almost all rainforest plants, is a heavy feeder, you should provide it with a high-quality fertilizer for flowering plants between March and October.

Fertilize the plant according to the instructions on the package about every two to four weeks. You should fertilize small plants less frequently than larger ones, as they naturally have lower nutrient requirements.

Make sure that the fertilizer contains little nitrogen, but instead has a phosphorus-rich composition. This promotes the formation of flowers, while nitrogen primarily drives shoot and leaf growth.

Always fertilize on the moist substrate and watch for signs of possible overfertilization.

Incidentally, you can also fertilize the peace lily very well with plain coffee grounds. But this is not sufficient as a permanent sole fertilizer.

Pruning Peace Lily

Regular pruning is neither necessary nor appropriate for the peace lily. You should only cut off faded and withered shoots just above the substrate base.

Propagating Peace Lily

You also do not need to cut back a peace lily that has grown too large to reduce the plant’s girth. Instead, you can easily divide such a specimen and get one or even several offshoots at the same time.

Here’s how it works:

  • Unpot the peace lily, free the roots from the soil.
  • Select division points.
  • Preferably cut off offshoots.
  • Each individual root section should have at least one sprout.
  • Separate the rootstock at the designated points with the help of a sharp knife.
  • Plant the now individual plantlets in their own pots each.

While dividing works quite reliably, propagating cuttings is virtually impossible with the peace lily. However, you can still use seeds to grow new plants.

It is quite difficult for the layman to get Spathiphyllum to germinate and then grow. This endeavor requires a lot of patience and good botanical knowledge.

Diseases and Pests in Peace Lily

The peace lily is very hardy and rarely becomes diseased. Signs of disease, such as leaves turning brown or yellow, are mostly due to caring errors. Therefore, you should treat them accordingly.

As far as pests are concerned, you can occasionally find mealybugs or aphids on Spathiphyllum. If you keep the plant too dry, it might as well get spider mites.

You can easily control these pests with an occasional warm shower or the more frequent use of a sprayer.

Yellow Leaves

Yellow leaves on peace lilies can have several causes:

  • Pest infestation
  • Lack of nutrients
  • Waterlogging

In particular, if the leaves are not only turning yellow but are also pendulous, you are most likely keeping the plant far too wet. It is likely that its roots have already begun to rot.

Immediately pot out the affected peace lily, cut away the diseased parts of the plant, including the rotten roots. then place it in a new planter with fresh substrate.

In the future, water the plant less and only after finger testing the substrate.

On the other hand, if the yellow leaves appear for no apparent reason, the almost invisible spider mites are often the reason. Since these pests like dry and warm weather, you can easily drive them away by increasing the humidity.

Brown Leaves and Leaf Spots

Monocots also usually react to care errors with leaves turning brown or leaf spots:

  • Brown leaf tips: This is a clear indication of too dry air. You should increase the air humidity.
  • Brown, withering leaves: This comes from overwatering (waterlogging) or lack of water. Repot the peace lily in fresh substrate or water it, depending on the cause.
  • Brown leaf spots or dots: The reason for this is overfertilization. Repot the peace lily in fresh substrate.
  • Dark brown, ring-shaped leaf spots: This is a sign for leaf spot disease. Cut off all infested leaves.

Green Flowers

Some varieties of the peace lily naturally have green-white or green bracts. So this is quite normal and you need not worry.

On the other hand, if the bracts on your variety are actually bright white instead of green, the location for the plant is most likely too dark.

In this case, moving it to a brighter spot will help, though, of course, you should avoid direct sunlight.

By the way, the white flowers that last for weeks turn greenish all by themselves after some time when they fade. This phenomenon is also completely normal and no reason for countermeasures.

Good to know

As a rule, the peace lily will remain healthier and thrive better if you keep the substrate relatively dry and, in return, spray the large leaves with water more frequently. In this way, you prevent not only the frequent, unsightly-looking brown leaf tips but also the heat and moisture-loving spider mites.

Species and Varieties

The most commonly cultivated species of the peace lily are:

  • Spathiphyllum floribundum: This variety comes with pearly white bracts and yellow flower bulbs. The leaves grow up to 8 inches (20 cm) long.
  • Spathiphyllum patinii: This variety is similar to Spathiphyllum floribundum, but with narrower and longer leaves
  • Spathiphyllum wallisii: This variety has green-white bracts and short flowering bulbs. It is a very tall species compared to the other ones.

In addition to the above species, there are also some interesting hybrid forms:

  • Gemini: variegated foliage
  • Chopin: stocky habit
  • Sweet Paco: delicate vanilla fragrance
  • Pearl Cupido: dark green, lanceolate leaves