How to Grow Hawaii Blue
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Hawaii Blue
Ipomoea tricolor 'Heavenly Blue'
vineHawaii Blue (Heavenly Blue) is a stunning morning glory vine known for its large, vibrant sky-blue flowers that open in the morning and close by afternoon. This fast-growing annual or tender perennial vine can reach 8-10 feet in a single season and produces hundreds of blooms throughout summer and fall. It's a beloved ornamental climber that brightens gardens and attracts pollinators.
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Example Hawaii Blue timeline · Pittsburgh, PA (Zone 6b)
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Plant Hawaii Blue
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 Hawaii Blue
Around Jun 6≈ 50 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Hawaii Blue dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives as an annual in zones 1-9; can be perennial in zones 10-11
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Seed Preparation
1 dayHard seed coat requires preparation before sowing
Soak seeds in warm water for 24 hours or lightly scarify with sandpaper to improve germination rates. This increases success from ~50% to 90%+.
Seedling
2-3 weeksTiny cotyledons emerge and first true leaves develop; vine is delicate
Keep soil warm (70-80°F) and consistently moist. Provide bright indirect light. Thin seedlings to prevent crowding. Transplant to individual pots when first true leaves appear.
Vegetative Growth
3-4 weeksRapid vine growth with increasingly larger heart-shaped leaves; minimal flowering
Install support structure (trellis, fence, pole). Water regularly. Pinch back early growth to encourage branching. Too much nitrogen promotes foliage over flowers.
Flowering
6-10 weeksLarge, delicate sky-blue flowers bloom abundantly in morning, closing by midday; blooms appear continuously
Flowers last one day each. Maintain consistent watering and moderate feeding. Remove any dead vines or diseased leaves. The vine produces hundreds of flowers throughout the season.
Seed Production
Ongoing through fallAfter flowering period, seed pods develop; plant may slow flowering late in season
Allow some pods to mature if collecting seeds for next year. Deadheading spent flowers encourages continued blooming. In warm climates, flowering may continue until frost.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick early morning; use neem oil or spinosad spray; encourage natural predators
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Spray with insecticidal soap or neem oil; use yellow sticky traps; spray undersides of leaves
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Increase humidity; spray with water; use miticide if severe; neem oil effective
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Spray with strong water stream; use insecticidal soap; apply neem oil; introduce ladybugs
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and
Remove debris; use copper barriers; beer traps; handpick at night
Uses
Garden Decoration and Vertical Screening
CraftHawaii Blue's vigorous growth and abundant sky-blue flowers make it ideal for covering trellises, arbors, fences, and pergolas. A single plant can cover 8-10 feet of vertical space in one season, providing dramatic color and natural screening from early summer through fall. [source]
Cut Flower Arrangement
HouseholdThe delicate blue flowers can be cut in early morning when freshly opened and used in flower arrangements and bouquets. Though individual flowers last only one day, a vine in full bloom provides daily fresh flowers throughout the season. [source]
Pollinator Attraction
WildlifeHawaii Blue flowers are highly attractive to bees, hummingbirds, and butterflies, making the vine excellent for supporting pollinator populations. A single blooming vine can sustain multiple pollinators throughout the growing season. [source]
Traditional Ethnobotanical Uses
MedicinalRelated morning glory species have been used in traditional medicine in various cultures, though Ipomoea tricolor itself is primarily ornamental. Modern use is primarily decorative; consult herbalists before any internal use. [source]
Ornamental Edible Flowers
CulinaryWhile not commonly eaten, the flowers are technically edible and can garnish salads or desserts for visual appeal. Use only flowers from plants grown without pesticides, and confirm no toxic treatments have been applied. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Hawaii Blue is grown for ornamental flowers, not harvest. Flowers bloom in the morning (typically 6-10 AM) and close by midday or early afternoon. To enjoy the blooms, observe the vine during morning hours. To collect seeds for replanting, allow pods to mature and dry on the vine in late season, then collect before frost. Seeds are ready when pods turn brown and papery.
Fun Facts
- 🌱 Hawaii Blue flowers contain indole alkaloids that cause the flowers to open in response to sunlight; they close in darkness or cloudy weather as a protection mechanism against moisture loss.
- 🌱 A single healthy plant can produce over 1,000 flowers during the growing season, with new blooms opening every day from mid-summer through fall frost.
- 🌱 The 'Heavenly Blue' cultivar was named for its extraordinarily vivid sky-blue color, which deepens slightly at the throat; no other morning glory variety matches its intensity and purity of blue.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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