How to Grow Round-leaved Sundew

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Round-leaved Sundew

Drosera rotundifolia

flower

A carnivorous perennial plant with distinctive round leaves covered in glistening, sticky tentacles that trap and digest insects. Native to boggy wetlands across the Northern Hemisphere, it produces delicate pink or white flowers on thin stalks. This fascinating plant thrives in nutrient-poor, acidic environments where it supplements its diet with captured prey.

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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: Full sun to partial shade, 4-6 hours of direct sunlight daily for optimal color and trap development
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Water: Keep consistently moist to wet; water with distilled water or rainwater only, never tap water. Soil should never dry out completely. Thrives in humid conditions with high moisture.
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Spacing: 4-6 inches between plants inches
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Days to maturity: 90-180 days to flowering from seed; typically flowers in second year
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Planting depth: Surface sow seeds; do not cover as they require light to germinate

Soil

Type: Acidic, nutrient-poor peat or sphagnum moss mix
pH: 4.0-5.5
Amendments:
Sphagnum peat moss Long-fiber sphagnum moss Perlite or sand for drainage Avoid fertilizers and nutrients

Growing Zones

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Thrives in zones 2-8, prefers cooler climates with cold winters

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a

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Growth Stages

1

Seed Germination

2-4 weeks

Tiny seeds begin sprouting on moist sphagnum surface; first leaves appear as microscopic rosettes

Maintain high humidity (80%+), keep soil surface wet, use distilled water only, provide bright light, stratify seeds in cold for 2-4 weeks prior to sowing

2

Rosette Development

8-12 weeks

Small round leaves emerge in a basal rosette pattern; sticky tentacles begin forming on leaf surfaces

Maintain wet conditions, provide 4-6 hours daily sun, ensure excellent air circulation to prevent fungal issues, resist fertilizing

3

Vegetative Growth

3-6 months

Rosette expands with more and larger round leaves covered in bright red or orange glandular tentacles; plant may produce runners or buds

Continue wet, humid conditions, allow plant to trap insects naturally for nutrition, maintain distilled water watering, thin overcrowded rosettes if needed

4

Flowering

4-8 weeks

Thin flowering stalks emerge from center of rosette bearing 5-15 small pink, white, or pale purple flowers arranged in a curled cyme

Maintain all previous conditions, do not disturb flower stalks, allow flowers to self-pollinate, ensure adequate light for seed production

5

Seed Production & Dormancy

8-12 weeks seed maturation; 3-4 months dormancy

Flowers fade and are replaced by capsules containing hundreds of tiny seeds; plant enters dormancy in fall/winter with reduced growth

Allow seeds to mature and dry on plant, reduce watering slightly in winter but keep soil moist, provide cold period (vernalization) for next season's growth, allow natural dormancy cycle

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Lime-loving plants Fertilizer-dependent plants Plants requiring alkaline soil Heavy feeders Plants intolerant of constant moisture

Common Pests

  • Improve air circulation, reduce humidity slightly, use sterile growing medium, avoid overwatering, consider yellow sticky traps

  • and (Botrytis, Powdery mildew)

    Ensure excellent air circulation, avoid crowding plants, reduce humidity if possible while maintaining moisture, remove affected leaves, increase light exposure

  • Increase humidity, mist plant with distilled water, improve air circulation, isolate affected plants, spray with water to remove mites

  • Allow natural predation by beneficial insects, wash off with distilled water spray, isolate heavily infested plants, remove affected leaves

Uses

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Traditional herbal remedy

Medicinal

Round-leaved sundew has been used in traditional European herbalism for respiratory conditions including coughs, whooping cough, and bronchitis. The plant contains naphthoquinones and other compounds believed to have expectorant and antispasmodic properties. [source]

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Botanical specimen and cultivation hobby

Craft

A prized plant for carnivorous plant collectors and specialized gardeners who create bog gardens and terrariums. Growing sundew presents a challenging and rewarding horticultural endeavor. [source]

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Insect predation and garden ecology

Wildlife

Naturally traps and digests insects including flies, gnats, and mosquitoes, supplementing nitrogen nutrition in poor soils. Helps naturally control pest insect populations in gardens and wetlands. [source]

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Bog garden and terrarium centerpiece

Household

The striking appearance of sticky leaf tentacles and delicate flowers makes sundew an attractive focal point for specialized bog terrariums and indoor plant collections. [source]

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Herbal tea ingredient (historical use)

Culinary

Historically, sundew leaves were dried and brewed into tea as a folk remedy. Modern herbalists occasionally include it in respiratory support blends, though cultivation difficulty limits common use. [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 as they are the plant's feeding mechanism. Collect seed pods after flowers fade and dry completely; store seeds in cool, dry conditions. Seeds remain viable 2-3 years. Divide rooted runners or dormant buds in spring for propagation. Allow plants to complete natural life cycle for best ongoing vigor.

Fun Facts

  • 🌱 The sticky tentacles on sundew leaves are not webs but rather glandular hairs that produce a sticky mucilage; when an insect becomes trapped, the leaf curls inward to bring the prey into contact with digestive enzymes, which can take several days to digest a single insect.
  • 🌱 Round-leaved sundew has been used in European folk medicine for centuries—the plant appears in medieval herbals and was particularly popular in Germanic and Scandinavian traditional medicine for treating respiratory ailments.
  • 🌱 Charles Darwin was fascinated by sundew and conducted extensive experiments on the plant in his greenhouse, documenting its carnivorous behavior and publishing findings in his 1875 book 'Insectivorous Plants,' establishing it as a key model organism for understanding plant carnivory.

Gardening Terms

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