How to Grow Red Sister

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Red Sister

Alternanthera dentata 'Red Sister'

flower

Red Sister is a striking ornamental foliage plant prized for its deep burgundy to crimson leaves that add dramatic color to gardens and containers. This tender perennial is typically grown as an annual in cooler climates and develops a compact, bushy habit with small, insignificant flowers. The vibrant leaf color intensifies with increased sunlight and cooler temperatures.

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Example Red Sister timeline · Pittsburgh, PA (Zone 6b)

Plant Red Sister
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
First Red Sister blooms
Around May 17

≈ 30 days after planting

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

Growing Conditions

☀️

Sun: Full sun to partial shade, 6+ hours daily; full sun intensifies leaf color

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Water: Keep soil consistently moist but not waterlogged. Water regularly during growing season; reduce in winter. Tolerates brief dry periods once established.

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Spacing: 12 inches

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Days to maturity: 30-45 days to reach ornamental size

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Planting depth: 1/4 inch for seeds; transplants at soil line

Soil

Type: Well-draining loamy soil with organic matter

pH: 6.0-7.0

Amendments:

Compost Peat moss Perlite for drainage

Growing Zones

Find your zone →

Zones 10-11; grown as an annual in cooler zones (5-9)

10b 11a 11b

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Growth Stages

Seedling

2-3 weeks

Tiny green seedlings emerge with oval cotyledons; true leaves develop with reddish tints

Maintain warm temperatures (70-80°F), high humidity, and consistent moisture. Provide bright indirect light.

Vegetative Growth

4-6 weeks

Plant develops bushy, compact growth with increasingly deep burgundy foliage; leaves become more lance-shaped

Pinch growing tips to encourage branching. Maintain full sun exposure for best color. Feed with balanced fertilizer every 2-3 weeks.

Establishment

Ongoing until frost or season end

Plant reaches mature size with full, dense foliage; deep crimson coloration develops throughout the plant

Continue regular watering and feeding. Prune to maintain desired shape. Color deepens with cooler nights and full sun.

Flowering

Throughout growing season (sporadic)

Small, inconspicuous white or pale purple flowers may appear in spike-like clusters

Flowers are not ornamentally significant; deadheading is optional. Focus on foliage maintenance.

Decline

Autumn to frost

In cooler climates, foliage may lose color and plant growth slows as temperatures drop

Reduce watering in fall/winter. Bring container plants indoors before frost in zones below 10. Can be overwintered indoors.

Companion Planting

Plan your garden →

Plant with:

Caladiums Coleus Dusty Miller Begonias Impatiens Sweet potato vine

Avoid planting near:

Aggressive fast-growing vines Tall plants that shade heavily

Common Pests

Spray with neem oil or insecticidal soap; increase humidity; rinse leaves regularly
Spray with strong water stream or insecticidal soap; use neem oil for severe infestations
Remove with rubbing alcohol on cotton swabs; spray with insecticidal soap or neem oil
Use yellow sticky traps; spray with neem oil or insecticidal soap; increase air circulation

Uses

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Container and Border Accents

Household

Red Sister's vibrant burgundy foliage creates striking focal points in containers, mixed borders, and landscape beds. The bold color provides excellent contrast against silver-foliaged plants or bright green backgrounds. [source]

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Indoor Houseplant

Household

This tender plant thrives as an indoor houseplant in bright, indirect light, making it ideal for sunny windowsills or under grow lights. It can be overwintered indoors in cooler climates. [source]

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Floral and Foliage Arrangements

Craft

The deep crimson leaves add sophisticated color to fresh and dried floral arrangements, wreaths, and decorative displays. Stems can be cut and conditioned for indoor arrangements. [source]

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Pollinator Garden Support

Wildlife

While the flowers are inconspicuous, they attract small pollinators and beneficial insects when they appear, contributing to garden biodiversity. [source]

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Tropical Garden Design

Household

Red Sister is essential for creating tropical and warm-climate garden designs, adding lush, colorful foliage that evokes warm-region landscapes. [source]

Harvest Tips

Red Sister is a foliage plant not harvested for consumption. Prune stems as needed to maintain shape and encourage bushier growth; remove any leggy or overgrown branches. Cuttings can be propagated in water or moist soil.

Fun Facts

🌱 Red Sister's color intensity responds dynamically to light and temperature—the cooler the nights and brighter the sun, the deeper the burgundy hue becomes.
🌱 This plant is part of the Alternanthera genus, which includes over 200 species of ornamental foliage plants, many with vibrant colors ranging from pink to orange to deep purple.
🌱 Red Sister can be propagated easily from stem cuttings, which will root in water within 1-2 weeks, making it ideal for sharing with other gardeners or creating backup plants for overwintering.

Gardening Terms

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

Annual Deadhead Full Sun Partial Shade Perennial True Leaves

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