How to Grow Double Gleam Nasturtium
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Double Gleam Nasturtium
Tropaeolum majus 'Double Gleam'
flowerDouble Gleam is a showy variety of garden nasturtium featuring semi-double flowers in vibrant shades of red, orange, and yellow. This tender annual climber produces lush foliage and attracts pollinators while being edible and useful for pest control in vegetable gardens.
When should you plant Double Gleam Nasturtium in your zone?
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Example Double Gleam Nasturtium timeline · Pittsburgh, PA (Zone 6b)
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Plant Double Gleam Nasturtium
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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First Double Gleam Nasturtium blooms
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Double Gleam Nasturtium dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 2-11; grows as tender annual, thrives in warm climates
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Seedling
2-3 weeksCotyledons emerge within 7-10 days; first true leaves appear shortly after with the characteristic round, shield-shaped form.
Keep soil consistently moist but not waterlogged. Provide bright light to prevent legginess. Avoid direct heat.
Vegetative
3-4 weeksPlant develops bushy growth with multiple stems and trailing vines. Leaves are round, peltate (shield-shaped), and vibrant green.
Thin seedlings to proper spacing. Provide support structure if growing as climber. Avoid excessive nitrogen fertilizer, which promotes foliage over flowers.
Flowering
6-10 weeks (until frost)Semi-double blooms appear in clusters at leaf axils in red, orange, and yellow hues. Flowers have ruffled petals and are held above foliage.
Deadhead spent flowers to encourage continuous blooming. Maintain moderate watering. Feed monthly with balanced fertilizer or low-nitrogen formulation.
Seed Development
2-3 weeks per pod setAfter flowers fade, distinctive round seed pods develop. Pods mature from green to tan/brown and become papery.
Allow some pods to mature if saving seeds for next year. Otherwise, continue deadheading to extend flowering. Seeds are easily collected when pods dry.
End of Season
Until first freezePlant declines with first frost (tender annual dies back). Foliage yellows and stems soften.
Harvest mature seed pods before hard frost. Clean up plant debris to prevent disease carryover. Save seeds in cool, dry location.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Strong water spray to dislodge; insecticidal soap; neem oil; encourage natural predators like ladybugs and lacewings
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Yellow sticky traps; reflective mulches; neem oil; insecticidal soap; pyrethrin if severe
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Hand-pick caterpillars; row covers on young plants; Bacillus thuringiensis (Bt); neem oil
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Increase humidity; strong water spray; neem oil; miticide if infestation severe
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and
Copper barriers; beer traps; hand-picking at night; diatomaceous earth; remove hiding spots
Uses
Edible Flowers & Peppery Garnish
CulinaryDouble Gleam nasturtium flowers have a peppery, slightly spicy flavor and are prized as ornamental garnishes for salads, desserts, and cocktails. The bright colors make them visually striking additions to culinary presentations. [source]
Natural Pest Control
HouseholdNasturtiums are renowned trap crops that attract aphids, whiteflies, and cabbage moths away from vegetables. Growing them near crops like tomatoes and brassicas protects the main harvest. [source]
Antimicrobial & Immune Support
MedicinalNasturtium contains glucosinolates and other compounds with antimicrobial properties. Historically used in herbal remedies to support immune function and respiratory health. [source]
Fresh & Pressed Flower Arrangements
CraftThe vibrant semi-double flowers are excellent for fresh flower arrangements, bouquets, and can be pressed for dried flower crafts, bookmarks, and botanical art projects. [source]
Pollinator Attractant
WildlifeDouble Gleam flowers attract bees, butterflies, and hummingbirds, making it valuable for supporting pollinator populations and biodiversity in gardens. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Flowers are edible and best harvested in morning when fully open. Pinch off individual blooms or snip with scissors. For seed saving, allow pods to fully mature and turn tan/brown on plant, then collect before frost. Seeds should be completely dry before storing. Flowers can be harvested continuously to promote more blooming throughout the season.
Fun Facts
- 🌱 Nasturtium seeds resemble tiny capers and can be pickled when green for a peppery condiment, though Double Gleam is primarily grown for its ornamental flowers.
- 🌱 The name 'Tropaeolum' comes from the Latin 'tropaeum' (trophy), referring to the plant's peltate leaves that resembled ancient Roman shields hung on trophies after victory.
- 🌱 Double Gleam was developed in the mid-20th century to produce fully double or semi-double flowers, unlike wild nasturtiums which have single blooms.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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