How to Grow Gunnera
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Gunnera
Gunnera manicata
herbGunnera is a dramatic herbaceous perennial known for its enormous, rhubarb-like leaves that can reach 5-6 feet in diameter, making it one of the largest-leafed hardy plants. Native to South America, it features imposing architectural foliage and striking red flower spikes that emerge in spring. This bold specimen plant creates an instant tropical or jungle-like atmosphere in temperate gardens.
When should you plant Gunnera in your zone?
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Example Gunnera timeline · Pittsburgh, PA (Zone 6b)
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Plant Gunnera
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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Harvest Gunnera
Around Nov 8≈ 240 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Gunnera dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 7-10; needs winter protection in zone 7
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Get my Gunnera timeline →Growth Stages
Dormancy & Winter Rest
November-March (4-5 months)Plant dies back completely in autumn; crowns lie dormant underground. Foliage disappears, leaving bare soil.
Provide winter protection in zones 7-8 with 12-18 inches of mulch, leaves, or straw. In colder zones, consider growing in containers and moving indoors. Ensure good drainage to prevent crown rot.
Spring Emergence & Early Growth
April-May (4-6 weeks)Red flower spikes emerge first from the crown, followed by unfurling leaves. New growth is compact and reddish.
Remove winter mulch gradually as temperatures warm. Begin watering generously. Feed with balanced fertilizer. Watch for frost damage on young growth.
Vegetative & Leaf Development
June-August (12-14 weeks)Massive leaves rapidly expand to full size, reaching 5-6 feet across. Plant grows taller and wider each week. Flower spikes mature into red, conical inflorescences.
Water abundantly and consistently; never allow soil to dry out. Feed every 4-6 weeks with balanced or high-nitrogen fertilizer to support massive leaf production. Remove any damaged leaves.
Flowering & Peak Foliage
July-September (8-10 weeks)Plant reaches maximum size with fully developed giant leaves and mature red flower spikes (12-18 inches long). Flowering continues throughout summer.
Continue consistent watering and monthly feeding. Dead-head spent flower spikes if desired (though they add architectural interest). Monitor for pests and diseases in humid conditions.
Senescence & Autumn Decline
October-November (4-6 weeks)Leaf growth slows, foliage begins yellowing and browning. Plant gradually retreats in preparation for dormancy.
Reduce feeding in late September. Allow foliage to die back naturally. Cut back dead leaves close to ground in late autumn. Begin applying winter mulch protection.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick, use copper tape barriers, beer traps, or organic slug pellets. Encourage predators like ground beetles.
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Inspect undersides of leaves; remove larvae from soil using nematodes, sticky traps, or beneficial insects. Hand-pick adults at night.
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Increase humidity by misting; spray with insecticidal soap or neem oil in dry conditions. Ensure adequate water as stress increases mite populations.
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Remove with alcohol-soaked cotton swabs; spray with insecticidal soap or neem oil weekly for 3-4 weeks.
Uses
Ornamental Statement Plant
HouseholdGunnera serves as a stunning focal point in gardens, creating instant drama and architectural interest with its massive leaves. Perfect for creating jungle-like or tropical garden designs in temperate zones. [source]
Habitat for Garden Insects & Amphibians
WildlifeThe enormous leaves provide shelter and shaded microhabitats for beneficial insects, spiders, and amphibians. When planted near water features, it supports frogs and salamanders. [source]
Edible Leaf Stalks (Gunnera tinctorum varieties)
CulinarySome Gunnera species' petioles (leaf stalks) are edible when cooked and were historically used in South American cuisine, though G. manicata is typically grown ornamentally. Use is limited in modern cultivation. [source]
Traditional South American Remedy
MedicinalIn its native regions, Gunnera has been used in traditional medicine for astringent and diuretic properties, though scientific evidence is limited. Not commonly used in contemporary herbalism. [source]
Decorative Dried Leaves
CraftLarge dried Gunnera leaves can be used in flower arrangements and craft projects, providing dramatic architectural elements for dried floral designs. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Gunnera is not harvested for edible parts. Enjoy the dramatic foliage visually throughout the growing season. Cut back all dead foliage in late autumn before applying winter mulch.
Fun Facts
- 🌱 Gunnera manicata holds the record for the largest leaves of any herbaceous plant in temperate climates, with individual leaves sometimes exceeding 10 feet in diameter in optimal conditions.
- 🌱 The plant's aggressive growth rate and massive size means a single mature plant can occupy 15-20 square feet, making it suitable only for spacious gardens or water features.
- 🌱 The scientific name comes from the reddish color of its flower spikes and foliage ('manicata' refers to the toothed leaf margins), and the genus is named after Johan Ernst Gunnerus, an 18th-century Norwegian bishop and botanist.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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