How to Grow Oblong-leaved Sundew

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Oblong-leaved Sundew

Drosera intermedia

flower

Oblong-leaved Sundew is a carnivorous plant native to boggy wetlands across North America, Europe, and Asia. It features distinctive reddish, glandular leaves arranged in a rosette that trap and digest insects for nutrients. This small, delicate plant produces thin flower stems with tiny white to pale pink flowers.

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

  1. Plant Oblong-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 Oblong-leaved Sundew blooms

    Mid-to-late summer

    Before the first fall frost (≈ Nov 8)

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

Growing Conditions

☀️
Sun: Partial to full sun, 4-6 hours of indirect or dappled sunlight daily; excessive heat and direct afternoon sun can stress the plant
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Water: Keep soil consistently moist to wet; use distilled or rainwater only, never tap water. High humidity (60-80%) is essential. The soil should never dry out completely.
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Spacing: 3-6 inches between plants; can grow as dense colonies in nature inches
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Days to maturity: Perennial; flowers appear in second year or later (30-40 days after flowering begins)
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Planting depth: Surface sown; seeds require light to germinate. Press seeds onto moist peat/moss surface without covering.

Soil

Type: Poor, acidic, nutrient-poor peat or sphagnum moss-based soil
pH: 4.0-5.5
Amendments:
Sphagnum peat moss Long-fiber sphagnum moss Perlite or sand for drainage Distilled water only (no fertilizers)

Growing Zones

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Thrives in cool to temperate zones 3-8; prefers northern climates with cool summers

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b

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Growth Stages

1

Seedling

4-8 weeks

Tiny rosettes with 2-4 reddish, glandular leaves barely visible

Maintain high humidity and constant moisture; provide bright indirect light; use distilled water only

2

Vegetative Growth

Several months to over a year

Rosette expands with 6-12 oblong red leaves covered in sticky tentacle-like glands

Keep soil consistently wet; ensure high humidity; do not fertilize; allow dormancy in winter if in cool climates

3

Flowering

4-6 weeks

Thin reddish flower stalk emerges from center, 4-8 inches tall, with small white to pale pink flowers opening sequentially

Maintain moisture and humidity; do not disturb flowers; allow pollination by small insects if possible

4

Seed Production

3-4 weeks

Flowers fade and produce small seed capsules containing thousands of tiny black or brown seeds

Allow capsules to dry on plant; collect seeds for propagation or allow self-seeding

5

Dormancy

2-4 months

In cool climates, rosette dies back to a compact hibernaculum (dormant bud) in winter

Reduce watering slightly but keep soil moist; provide cool period (40-50°F) over winter for hardiness

Companion Planting

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Plant with:

Sphagnum moss (essential substrate) Butterwort (Pinguicula) Bladderwort (Utricularia) Bog rosemary (Andromeda polifolia) Cranberry (Vaccinium) Sundew species (other Drosera)

Avoid planting near:

Fertilized plants Mineral-rich soil amendments Tap water-dependent plants Aggressive spreading plants Plants requiring alkaline soil

Common Pests

  • Improve air circulation; reduce humidity slightly; use sticky traps; allow soil surface to dry slightly between waterings if possible

  • and

    Ensure excellent air circulation; reduce humidity if mold appears; remove affected leaves; allow partial drying of foliage

  • Increase humidity; mist foliage with distilled water; improve air circulation; in severe cases use sulfur dust (not oil-based products)

  • Manually remove with soft brush; improve air circulation; avoid overwatering

Uses

🦋

Insect Trap & Natural Pest Control

Wildlife

The sticky glandular tentacles trap and digest small flying insects (gnats, midges, mosquitoes), supplementing the plant's nutrient intake in poor soils. A single plant can capture dozens of insects daily in active growing season. [source]

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Specialized Cultivation & Hobbyist Collection

Craft

Oblong-leaved Sundew is highly prized by carnivorous plant collectors and bog garden enthusiasts for its delicate beauty and challenging cultivation requirements. Growing it successfully requires specialized knowledge of wetland ecology. [source]

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Traditional Herbal Medicine

Medicinal

Historically used in traditional European and Asian herbalism as a remedy for coughs, respiratory congestion, and digestive issues, though modern scientific evidence is limited. The plant contains compounds that may have antitussive properties. [source]

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Terrarium & Vivarium Specimen

Household

Ideal for paludarium vivariums, bog terrariums, and specialized carnivorous plant display cases that maintain high humidity and provide distilled water systems. Creates a living display of natural predation. [source]

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Bog Habitat Restoration

Wildlife

Native to endangered peatland and wetland ecosystems, cultivating Oblong-leaved Sundew supports biodiversity conservation efforts and habitat restoration in appropriate regions. [source]

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

Harvest Tips

Do not harvest leaves; this is a display/cultivation plant. Collect mature seed capsules in late summer/fall by allowing them to fully dry on the plant, then gently shake seeds into paper envelope. Seeds are extremely tiny and numerous. Store dry seeds in refrigerator in sealed container for propagation.

Fun Facts

  • 🌱 Oblong-leaved Sundew produces incredibly sticky mucilage on its tentacle-like glands that can trap insects much larger than the plant itself; the insects' struggles trigger the plant to slowly roll its leaves inward to maximize digestive enzyme contact.
  • 🌱 This species is one of the most cold-hardy sundews and can survive temperatures well below freezing by entering winter dormancy, making it suitable for cultivation in northern climates where other carnivorous plants fail.
  • 🌱 The name 'sundew' comes from the dewlike appearance of the glandular secretions, which sparkle in sunlight and historically led people to believe the plants were covered in morning dew even in dry conditions.

Gardening Terms

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