How to Grow Cardinal Royal

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Cardinal Royal

Ipomoea × multifida

vine

Cardinal Royal is a stunning tropical flowering vine known for its deep crimson-red, deeply lobed flowers that resemble small pompoms or coral-like clusters. It's a vigorous grower that produces masses of showy blooms throughout the growing season, making it an excellent choice for trellises, arbors, and hanging baskets. This tender perennial is typically grown as an annual in cooler climates.

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Example Cardinal Royal timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Cardinal Royal

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Cardinal Royal

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Cardinal Royal 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: Keep soil consistently moist but not waterlogged during growing season; reduce watering in winter. Benefits from regular misting in dry climates.
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Spacing: 12 inches
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Days to maturity: 60-90 days to first flowers
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Planting depth: 0.25 inches for seeds; transplants at soil level

Soil

Type: Well-draining, fertile loamy soil
pH: 6.0-7.0
Amendments:
compost peat moss perlite for drainage

Growing Zones

Find your zone →

Thrives in zones 9b-11; grow as annual in cooler zones

9b 10a 10b 11

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Growth Stages

1

Seedling

2-3 weeks

Tiny seedlings with cotyledons emerge; first true leaves are heart-shaped and simple.

Maintain warm conditions (70-75°F), high humidity, and bright indirect light. Keep soil moist. Thin seedlings to prevent crowding.

2

Vegetative Growth

4-6 weeks

Vine develops multiple stems with deeply lobed, palmate leaves. Plant grows rapidly and becomes bushy.

Provide sturdy support structure. Pinch growing tips early to encourage branching. Feed monthly with balanced fertilizer.

3

Budding & Early Flowering

3-4 weeks

Flower buds form at leaf axils; first deep red pompom-like blooms appear at stem tips.

Switch to higher-phosphorus fertilizer to support flowering. Maintain consistent moisture and full sun. Remove any dead or diseased growth.

4

Peak Flowering

8-12 weeks (or until frost)

Plant is covered with vibrant crimson-red clustered flowers that bloom continuously.

Deadhead spent flower clusters to encourage continuous blooming. Water regularly. Provide afternoon shade in very hot climates to prevent flower fade.

5

Seed Development & End of Season

4-6 weeks

If flowers are left unpruned, small round seed pods develop. Growth slows as temperatures cool in fall.

Can collect seeds from mature pods for next year if desired. Prepare to bring indoors or harvest before first frost in cool climates.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

black walnut eucalyptus

Common Pests

  • Increase humidity, mist foliage regularly, spray with neem oil or insecticidal soap if infestation occurs

  • Use yellow sticky traps, spray affected areas with insecticidal soap or neem oil, introduce parasitic wasps

  • Isolate affected plant, spray with rubbing alcohol or insecticidal soap, remove with cotton swabs dipped in alcohol

  • Spray with strong water stream, apply neem oil or insecticidal soap, encourage natural predators like ladybugs

Uses

🌿

Tropical Garden Focal Point

Ornamental

Cardinal Royal's vibrant crimson pompom flowers make it a stunning vertical accent plant for trellises, pergolas, and arbors. Its abundant blooms and vigorous growth create a dramatic tropical atmosphere in gardens and containers. [source]

🌿

Container & Basket Gardening

Ornamental

Excellent in large containers and hanging baskets where its vining stems can cascade or be trained upward. Brings continuous color to patios and entryways throughout the growing season. [source]

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Pollinator Attraction

Wildlife

The clustered, nectar-rich flowers attract hummingbirds and butterflies, making it an excellent addition to pollinator gardens. Provides nectar source during mid to late summer months. [source]

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Edible Flowers

Culinary

The flowers are edible and can be used as garnish for gourmet dishes, adding visual appeal and a slightly sweet flavor. Use fresh in salads or as decoration for desserts. [source]

Harvest Tips

Cardinal Royal is grown for ornamental flowers rather than harvest. Deadhead spent blooms throughout the growing season by pinching off flower clusters just below the spent flowers to encourage continuous blooming. Collect seed pods in late season if desired for seed saving—allow pods to dry on the plant, then collect before they split open.

Fun Facts

  • 🌱 Cardinal Royal is a hybrid (Ipomoea × multifida) created by crossing different morning glory species, combining the best ornamental traits of its parents.
  • 🌱 The deep crimson flowers closely resemble the flowers of coral vines and are sometimes called 'Scarlet Ipomoea' or 'Mexican Morning Glory hybrid'.
  • 🌱 Despite belonging to the morning glory family (Convolvulaceae), Cardinal Royal flowers often stay open longer than typical morning glories, sometimes blooming throughout the day in ideal conditions.

Gardening Terms

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

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