How to Grow Crimson Night

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Crimson Night

Ipomoea purpurea 'Crimson Night'

vine

Crimson Night is a vigorous annual morning glory cultivar prized for its deep crimson-red flowers with a darker throat. This fast-growing vine produces abundant blooms throughout summer and fall, making it ideal for trellises, arbors, and vertical garden features. The heart-shaped leaves provide lush foliage that complements the striking flower display.

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Example Crimson Night timeline · Pittsburgh, PA (Zone 6b)

Plant Crimson Night
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Crimson Night
Around Jun 6

≈ 50 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Crimson Night dates for your own zip code.

Growing Conditions

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Sun: Full sun, 6-8 hours daily for best flowering

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Water: Moderate watering; keep soil consistently moist but not waterlogged. Water deeply 1-2 times per week depending on heat and rainfall. Reduce watering slightly once established to encourage flowering.

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Spacing: 12 inches

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Days to maturity: 50-70 days to first flowers

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Planting depth: 0.5 inches; soak seeds 24 hours before planting to improve germination

Soil

Type: Well-draining loamy to sandy soil

pH: 6.0-7.5

Amendments:

Compost Peat moss Perlite for drainage

Growing Zones

Find your zone →

Thrives in zones 2-10 as an annual; perennial in zones 9-10

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b

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Growth Stages

Germination & Seedling

1-3 weeks

Seeds sprout into small seedlings with oval cotyledons, developing true leaves within 1-2 weeks.

Keep soil warm (70-80°F) and moist. Provide bright light once sprouted. Thin seedlings to proper spacing. Direct sow after last frost or start indoors 4-6 weeks prior.

Vegetative Growth

3-4 weeks

Vines rapidly develop heart-shaped leaves and establish climbing stems. The plant grows vigorously, extending 6-12 inches per week in favorable conditions.

Provide sturdy support structure (trellis, string, or netting). Keep soil consistently moist. Apply balanced fertilizer monthly or use slow-release fertilizer at planting.

Budding

1-2 weeks

Small flower buds form along the vine stems, often in clusters. Buds are initially green and gradually increase in size.

Maintain consistent watering and support growth with gentle ties or clips. Avoid over-fertilizing with nitrogen, which favors foliage over flowers. Continue regular feeding with balanced or slightly phosphorus-rich fertilizer.

Flowering

8-12 weeks (from first flower until frost)

Crimson to deep red flowers open in the morning, typically closing by afternoon. Blooms are 2-3 inches wide with a darker center throat. Flowering is prolific and continuous.

Deadhead spent flowers to encourage continuous blooming (optional, as self-seeding is desirable). Maintain moisture and warmth. Watch for pests attracted to blooms. Support heavy vine growth with additional ties.

Seed Production & Senescence

4-6 weeks before frost

After flowers fade, small green seed pods develop. Pods dry and turn brown, containing 1-4 seeds each. Vines slow growth as temperatures cool in fall.

Allow some seed pods to mature if you want self-seeding or seed collection. Allow vines to die back naturally with fall frost. Collect mature seed pods before frost for storage or next year's planting.

Companion Planting

Plan your garden →

Plant with:

Zinnias Sunflowers Marigolds Salvia Verbena Black-eyed Susans Lavender

Avoid planting near:

Beans Peas Root vegetables (can compete for nutrients) Plants requiring full sun if morning glories will shade them

Common Pests

Spray with water to dislodge; use neem oil or insecticidal soap if severe. Ensure adequate humidity.
Use yellow sticky traps, insecticidal soap, or neem oil. Remove heavily infested leaves.
Hand-pick in early morning, use pheromone traps, or apply neem oil. Remove affected foliage.
and
Handpick, use copper tape barriers, or apply slug bait. Remove debris where they hide.
Spray with strong water stream, use insecticidal soap, or apply neem oil. Introduce ladybugs.

Uses

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Vertical Garden Coverage

Ornamental

Crimson Night is excellent for covering trellises, arbors, fences, and pergolas with vibrant color. The rapid growth and prolific flowering make it ideal for creating living screens and adding height to garden designs. [source]

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Pollinator Attraction

Wildlife

The abundant flowers attract hummingbirds, bees, and butterflies, making it valuable for supporting pollinator populations in gardens. The sweet nectar is a reliable food source throughout the growing season. [source]

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Cut Flowers & Arrangements

Craft

While morning glories close in afternoon, their vibrant morning blooms can be cut early in the day for fresh arrangements and floral displays. The distinctive flowers add striking color to bouquets. [source]

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Privacy & Shade Enhancement

Household

Fast-growing vines provide quick natural screening and light shade on structures. Ideal for creating secluded garden spaces or reducing heat on walls and south-facing structures. [source]

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Traditional Ethnobotanical Uses

Medicinal

Morning glory seeds contain ergot alkaloids and have been used in traditional medicine and rituals, though they carry significant toxicity risks and should not be ingested without expert guidance. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Morning glories are grown primarily as ornamentals for their flowers, which open in the morning (typically 6-10 AM) and close by afternoon. Deadhead spent flowers to maintain neat appearance and encourage more blooms, though allowing some flowers to set seed is fine. Harvest seeds in late fall when pods turn brown and papery; dry completely before storing in cool, dry conditions for next year's planting.

Fun Facts

🌱 Morning glory flowers open in the early morning and close by mid-afternoon, following a circadian rhythm triggered by light exposure. This behavior is so reliable that some cultures used morning glory blooms as natural 'flower clocks.'
🌱 Crimson Night is part of the Convolvulaceae family, which includes over 1,600 species of flowering plants ranging from ornamental vines to sweet potatoes.
🌱 Morning glory seeds were used ceremonially by Aztecs and other Mesoamerican cultures for their psychoactive properties, making them one of the oldest cultivated plants with documented spiritual significance.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Annual Cultivar Deadhead Direct Sow Full Sun pH Trellis True Leaves

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