How to Grow Bog Arum
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Bog Arum
Calla palustris
flowerBog Arum is a hardy, semi-aquatic perennial native to northern temperate wetlands, featuring heart-shaped leaves and distinctive white spadix flowers surrounded by white spathes. This low-growing plant thrives in boggy, marshy conditions and is prized for its unique architectural form and ability to stabilize wet edges. It produces ornamental red berries in late summer.
When should you plant Bog Arum in your zone?
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Example Bog Arum timeline · Pittsburgh, PA (Zone 6b)
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Plant Bog Arum
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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First Bog Arum blooms
Mid-to-late summerBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Bog Arum dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-8; prefers cool northern climates
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Get my Bog Arum timeline →Growth Stages
Emergence
3-4 weeksRhizomes break dormancy in spring; first heart-shaped leaves unfurl from crowns
Ensure soil remains consistently wet; protect emerging shoots from frost damage in cold zones
Vegetative Growth
4-6 weeksMultiple heart-shaped leaves on long petioles develop; plant spreads via creeping rhizomes
Maintain wet conditions; monitor for slugs and snails; avoid disturbing rhizomes
Flowering
3-4 weeksDistinctive white flowers emerge with prominent spadix and white spathe; flowers appear June-July
Maintain moisture; deadhead only if desired (berries are ornamental); flowers are pollinated by flies
Fruiting
8-10 weeksGreen berries develop on spadix, gradually turning bright red by late summer/fall
Leave berries on plant for ornamental and wildlife value; seeds viable for 1-2 years
Dormancy
4-5 monthsFoliage yellows and dies back in fall; rhizomes overwinter underground, protected by water and soil
Do not cut back foliage; allow natural senescence; maintain water cover over rhizomes in cold zones
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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and
Hand-pick; copper barriers around plants; encourage natural predators like ground beetles
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Generally beneficial for pollination; tolerate population; insecticides rarely needed in bog settings
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Ensure adequate water circulation; avoid stagnant anoxic conditions; improve drainage in poorly aerated soils
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and
Protect young plantings with screening; coexist in natural wetlands; fencing in cultivated gardens
Uses
Wetland Wildlife Habitat
WildlifeBog Arum provides shelter and food for wetland fauna, including insects that pollinate the flowers and birds that consume the red berries. The dense rhizome network stabilizes soft wetland substrates. [source]
Ornamental Bog Garden Feature
CraftThe distinctive white flowers and bright red berries make Bog Arum a striking element in bog gardens, water margins, and specialized wetland landscapes. Its unique sculptural form complements other bog plants. [source]
Container Water Garden
HouseholdBog Arum thrives in submerged or semi-submerged containers, making it ideal for water features, artificial ponds, and enclosed water gardens where wetland conditions are replicated. [source]
Traditional Ethnobotanical Use
MedicinalHistorically used in traditional European folk medicine for digestive ailments, though the plant contains irritating calcium oxalate crystals. Modern use is not recommended due to toxicity concerns. [source]
Not Edible
CulinaryBog Arum berries and all plant parts are toxic and should never be consumed. The plant contains saponins and oxalates that cause gastrointestinal irritation and oral burning. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Bog Arum is not harvested for culinary or medicinal use. Berries are toxic and should not be consumed. For ornamental purposes, cut flower stems just as white spathes emerge; berries can be left on plant for fall color and wildlife food. Rhizome division for propagation is done in spring before growth begins.
Fun Facts
- 🌱 Bog Arum flowers are pollinated primarily by flies and gnats attracted to the plant's carrion-like scent, an unusual strategy among temperate flowers.
- 🌱 The plant is one of the few true semi-aquatic arums native to the Northern Hemisphere and can survive under water for extended periods, making it a pioneer species in newly flooded wetlands.
- 🌱 Despite its common name 'Bog Arum,' it is not closely related to the tropical Zantedeschia aethiopica (calla lily), though both are in the Araceae family and share the distinctive spathe-spadix inflorescence.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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