Calla palustris aka Peace Lilly

Calla palustris is a slow-growing plant, typically reaching 15-30 cm (6-12 inches) in height and gradually spreading outward via rhizomes to form colonies in shallow water or wet soil. Individual plants spread roughly 15-30 cm, but established colonies in favorable conditions can extend considerably further over time.

Calla palustris is cold-hardy and adapted to cool to cold temperate climates. It is rated for USDA hardiness zones 2-6 by NC State Extension (PFAF rates it zones 4-8), tolerating severe winters across boreal North America, northern Europe, and northern Asia. It does not perform well in warm, subtropical, or tropical climates.

As an obligate wetland plant growing naturally in bogs, swamps, and pond margins, Calla palustris thrives in consistently high ambient humidity. It is not suited to dry indoor environments and performs best when grown at the edge of water features or in waterlogged soil outdoors.

No source consulted specifically reports a notable scent for the flowers or foliage of Calla palustris. The spadix attracts syrphid and carrion flies, suggesting the inflorescence may emit an odor that mimics decaying matter, though no source explicitly describes this.

The inflorescence of Calla palustris consists of a cylindric spadix of densely packed tiny petalless flowers enclosed in a smooth, waxy, oval white spathe typically 3-8 cm (1-3 inches) long. The spadix is greenish-yellow and approximately 4-6 cm long. Blooming occurs from May through July depending on location. After flowering, the plant produces clusters of bright red, pear-shaped berries up to 1.5 cm (½ inch) in diameter, which are highly ornamental and persist into autumn.

Calla palustris belongs to a monotypic genus — it is the only species in the genus Calla. No cultivars or named varieties are documented in the sources consulted.

Calla palustris is strictly an outdoor bog or marginal aquatic plant. It requires wet to waterlogged, lime-free, humus-rich, acidic soil in full sun to partial shade, and can grow in water depths of up to 25 cm. It is native to boreal and cool temperate wetlands across North America, northern Europe, and northern Asia, and is hardy to USDA zones 2-6. It is ideal for pond margins, bog gardens, rain gardens, and stream edges. It spreads readily by rhizome and can form colonies.

No specific pruning requirements are documented for Calla palustris. As a low-maintenance wetland perennial, spent flower stalks and dead foliage can be removed in autumn or early spring, but no regular pruning is necessary.

Calla palustris is typically grown as a marginal aquatic plant in outdoor pond baskets or directly in boggy soil. If grown in an aquatic container, division of the rhizomes every few years in spring will help manage its spread and reinvigorate growth.

No specific leaf-cleaning requirements are noted for Calla palustris. The leaves are described as waxy and smooth; in an outdoor setting, rain typically keeps them clean. Remove dead or yellowing leaves at the base to maintain appearance.

Calla palustris is propagated by seed or by division of rhizomes. Seeds should be sown immediately when ripe. Division of the rhizome is considered the easiest method and is best done in spring. Stem cuttings can also be rooted in wet mud.

Yellowing leaves in Calla palustris are most commonly caused by insufficient moisture — the plant requires persistently wet or waterlogged conditions. Allowing the soil to dry out even briefly can cause stress and leaf yellowing. Nutrient deficiency in very poor soils may also contribute.

Brown leaf tips or margins in Calla palustris typically indicate insufficient water or low humidity. As an obligate wetland species, this plant suffers quickly when moisture is inadequate. Brown foliage in autumn is normal as the plant enters dormancy.

Drooping leaves in Calla palustris are most likely a sign of water stress — either insufficient soil moisture or the plant being out of water in an aquatic container. Ensure the root zone remains continuously wet or submerged.

Calla palustris is a herbaceous perennial and will naturally die back in autumn and winter in temperate climates, regrowing from the rhizome in spring. This is normal seasonal behavior, not a sign of disease or stress.

Calla palustris is inherently a slow-growing plant. Growth can be further limited by insufficient light (it prefers full sun to partial shade), alkaline or lime-rich soil (it requires acidic, lime-free conditions), or inadequate moisture. Ensuring consistently wet, humus-rich, acidic soil in a sunny location will support the best growth rate.

No serious pest or disease problems are reported for Calla palustris in the sources consulted. The plant is generally considered low-maintenance and not particularly susceptible to common garden pests or diseases.

Calla palustris is pollinated by syrphid flies (hoverflies) and carrion flies, which are attracted to the spadix inflorescence. The spathe-and-spadix structure is typical of the Araceae family, where the spadix generates heat and odor to attract pollinators. After pollination, clusters of bright red berries develop and are dispersed by water and birds.

All parts of fresh Calla palustris are toxic due to calcium oxalate crystals, which cause intense burning and swelling of the mouth and throat if consumed raw. However, the rhizome, fruit, and seeds become edible after thorough drying, grinding, and cooking, which neutralizes the crystals. Indigenous peoples of North America historically processed the rhizome into a starchy flour used for bread-making, and dried berries and seeds were also consumed. Edibility rating is 2 out of 5 — the plant has some food use but requires significant processing and is best considered a survival or traditional food source rather than a culinary ingredient.

Calla palustris has a medicinal rating of 2 out of 5. Indigenous North American peoples used root tea to treat flu, shortness of breath, bleeding, and swellings, and applied preparations to snakebites and sore legs. The plant has documented antirheumatic properties. Medicinal use requires careful preparation due to the toxicity of raw plant material.

No significant other uses beyond food and medicine are documented for Calla palustris. Its primary landscape value is ornamental — the white spathe, dark green foliage, and bright red berries make it an attractive plant for pond margins and bog gardens.

If you're looking for a plant that offers a moderate level of challenge, Peace Lilly is a great choice to test your gardening skills.

Peace Lilly’s native range is Europe. Naturalized in Britain[17].

Peace Lilly should be watered regularly, allowing the soil to dry out between waterings.

Peace Lilly is very sensitive to dry soil. To ensure your Wild Calla is thriving and blooming, choose a potting soil that retains moisture. A good soil should still allow for adequate drainage and contain lots of organic matter. Coco coir or sphagnum moss are great soil additives that will help to retain moisture and provide your Wild Calla Lily with the nutrients it needs for healthy growth. Make sure to mix these soil additives into the potting soil before planting and water the soil thoroughly. By providing your Peace Lilly with a well-draining, moisture-retaining soil, you can help to maximize its growth and keep it blooming.

Peace Lilly requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Wild Calla is always in the right place to thrive.

The Peace Lilly grows at a slow pace and doesn't require any supplementary fertilizers. By renewing its potting soil once a year, it should receive enough nourishment. Remember, plants obtain their energy from sunlight, not fertilizers.

Peace Lilly is poisonous if ingested. We suggest keeping this plant out of reach if you have children, cats, or dogs in the home.

During the cold period, it is common for Peace Lilly to go dormant, resulting in a slowdown of growth. To accommodate this, waterings should be spaced out more.