How to Grow Gunnera
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Gunnera
Gunnera manicata
perennialGunnera is a dramatic architectural perennial known for its massive heart-shaped leaves that can reach 5-6 feet across, making it one of the largest-leaved hardy plants available. Native to Brazil, it thrives in moist, sheltered locations and creates a striking tropical effect in temperate gardens. The plant also produces unusual cone-like flower spikes in spring followed by red berry clusters.
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
Late summer into fallBefore the first fall frost (≈ Nov 8)
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 7b-10, with protection needed in zone 7
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Get my Gunnera timeline →Growth Stages
Establishment
First yearYoung plant with modest leaves 1-2 feet across, developing rhizome system
Keep consistently moist; provide shelter from wind; mulch heavily; protect from frost in zone 7
Early Growth
Second yearLeaves expand to 2-3 feet; plant fills out horizontally; rhizome becomes more robust
Continue heavy watering; apply thick mulch layer (3-4 inches) in winter; feed with balanced fertilizer in spring
Flowering
Spring, 2-4 weeksConical flower spikes emerge in spring, followed by attractive red berry clusters
Flowers are secondary to foliage appeal; allow berries to persist for ornamental value
Dormancy
Winter dormancyDies back completely in winter; rhizome remains protected underground
Apply thick protective mulch (6+ inches) in cold zones; cut back dead foliage after frost; cover with leaves or straw in zone 7
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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and
Hand-pick; use organic slug pellets or copper tape; encourage natural predators; reduce moisture near young leaves
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Increase humidity; spray with water; use insecticidal soap if severe
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Inspect rhizomes before planting; spray with horticultural oil in early spring
Uses
Dramatic Focal Point
OrnamentalThe enormous leaves create an unmatched architectural statement in any garden, evoking tropical and prehistoric landscapes. Use as a specimen plant to draw the eye or frame water features. [source]
Wildlife Shelter and Food
WildlifeThe dense foliage provides shelter for beneficial insects, amphibians, and small animals. The spring flowers attract pollinators and red berries feed birds. [source]
Water Garden Design
HouseholdIdeal for marginal planting at pond edges or in bog gardens. The tropical appearance enhances water feature aesthetics while tolerating wet soil conditions. [source]
Architectural Landscape Design
CraftUsed by landscape designers to create bold textural contrasts and define garden spaces. The leaves can be used in large-scale fresh or dried arrangements. [source]
Harvest Tips
Gunnera is grown for ornamental foliage, not harvested for food or material. Remove damaged or diseased leaves throughout the growing season. Cut back completely after first frost; the plant will re-emerge from the rhizome in spring. Divide rhizomes in early spring for propagation.
Fun Facts
- 🌱 Gunnera manicata produces some of the largest leaves of any hardy perennial in temperate climates—leaves can reach 5-6 feet across and weigh several pounds when fully hydrated.
- 🌱 Despite its tropical appearance, mature plants are surprisingly cold-hardy in zone 7 with proper winter protection, as the rhizome survives freezing when mulched adequately.
- 🌱 The flowers are relatively inconspicuous but fascinating: reddish-brown cone-like structures that emerge before the full leaf canopy and later develop into striking red berry clusters.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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