How to Grow Round-leaved Sundew

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Round-leaved Sundew

Drosera rotundifolia

flower

Round-leaved Sundew is a carnivorous plant with distinctive circular leaves covered in glistening, sticky tentacles that trap and digest insects. Native to boggy wetlands in the Northern Hemisphere, this delicate plant produces small pink or white flowers on thin stems. It thrives in acidic, nutrient-poor environments where it supplements its diet through insect digestion.

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Example Round-leaved Sundew timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Round-leaved Sundew

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Round-leaved Sundew blooms

    Mid-to-late summer

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Round-leaved Sundew dates for your own zip code.

Growing Conditions

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Sun: Bright light, 4-6 hours of indirect sunlight daily; filtered light or partial shade preferred
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Water: Keep consistently wet year-round; use only distilled or rainwater, never tap water. Soil should never dry out. Mist regularly to maintain high humidity (60-80%+). Grows naturally in bogs and wetlands.
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Spacing: 3-6 inches
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Days to maturity: Variable; flowering occurs at 2-3 years from seed
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Planting depth: Seeds scattered on soil surface; do not bury (requires light to germinate)

Soil

Type: Acidic, nutrient-poor peat or sphagnum-based soil; must remain constantly moist
pH: 4.0-5.5
Amendments:
Sphagnum peat moss Long-fibered sphagnum moss Distilled water (critical—avoid tap water minerals)

Growing Zones

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Thrives in zones 2-7; prefers cool, humid climates

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b

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Growth Stages

1

Seed Germination

3-4 weeks

Tiny seeds germinate on moist sphagnum surface; cotyledons emerge as microscopic leaves

Maintain high humidity (90%+), keep on light-colored or clear covering, use only distilled water, maintain cool temperatures (65-75°F)

2

Seedling & Rosette Formation

3-6 months

Small round leaves develop in a basal rosette; leaves begin producing sticky tentacles (glands) for trapping insects

Ensure bright, indirect light; maintain waterlogged conditions; mist frequently; keep in humid environment; continue distilled water only

3

Vegetative Growth

1-2 years

Rosette expands with larger leaves; more glands develop; plant establishes stronger root system

Maintain bog-like conditions; allow plant to rest in winter with cooler temperatures; provide bright light; protect from direct afternoon sun

4

Flowering

2-4 weeks

Thin flower stems (inflorescence) emerge from rosette center; small pink, white, or red flowers appear in clusters

Plant needs to be mature (typically 2-3 years); maintain consistent moisture and humidity; do not disturb flower stems; allow natural pollination or hand-pollinate

5

Seed Production & Dormancy

6-8 weeks flowering period; dormancy 2-3 months

Flowers produce small seed capsules; plant prepares for winter dormancy with reduced growth

Allow seeds to mature on plant; collect seeds once dry; reduce watering slightly in winter but keep soil moist; maintain cool dormancy period (35-50°F for 2-3 months)

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Tap water sources Fertilized plants Plants requiring dry soil High-nutrient soil plants Lime-loving plants

Common Pests

  • Ensure excellent air circulation, reduce humidity slightly if mold appears, remove affected leaves, sterilize tools; avoid stagnant water conditions

  • Use sterile, well-aerated growing medium; maintain proper water quality; ensure good drainage with periodic air gaps; repot if necessary in fresh medium

  • Increase humidity to 70%+ (mites dislike moisture); rinse leaves with distilled water; isolate infested plants; avoid pesticides (harmful to carnivorous plants)

  • Reduce surface moisture; use sand topdressing; yellow sticky traps; allow partial drying of moss surface; improve air circulation

Uses

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Traditional respiratory remedy

Medicinal

Historically used in folk medicine to treat coughs, asthma, and whooping cough in Northern European traditions. The plant has been prepared as tinctures or dried preparations, though scientific evidence is limited. [source]

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Insect ecosystem support

Wildlife

As a carnivorous plant, sundews trap and digest insects, playing an ecological role in wetland food webs. Growing sundews supports biodiversity in bog ecosystems. [source]

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Botanical specimen & hobby growing

Craft

Prized by carnivorous plant collectors and botanical enthusiasts for its unique appearance and interesting biology. Growing challenges make it rewarding for specialized gardeners. [source]

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Natural pest control

Household

The sticky glands naturally trap flying insects (flies, gnats, midges), providing gentle biological pest control indoors without chemicals. [source]

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Specialty preservation

Culinary

Rarely, sundew is used to make specialty cordials or medicinal syrups in Nordic cuisines, though consumption is not common in modern kitchens. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

This is a carnivorous ornamental plant, not typically harvested for food. Collect seeds in late summer/early fall once seed pods dry; store in cool, dry conditions. Allow the plant to flower naturally for seed production. Never harvest leaves or disturb the plant's natural insect-trapping function.

Fun Facts

  • 🌱 The glistening, sticky droplets covering sundew leaves look like dewdrops but are actually mucilaginous secretions that trap insects—the plant's 'sticky traps' are more effective than traditional flypaper.
  • 🌱 Round-leaved Sundew has been used for centuries in Scandinavian folk medicine and appears in historical herbals; it was even believed to have magical properties in medieval times.
  • 🌱 Unlike Venus Flytraps, sundews do not snap shut; instead, they slowly curl their leaf tentacles (called 'tentacles') around trapped insects over several hours to maximize nutrient absorption—a patient, methodical approach to digestion.

Gardening Terms

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