Plant guide

Joyweed.

Alternanthera polygonoides

Pronounced al-ter-NAN-ther-uh

Also known as Alternanthera polygonoides, Joyweed

Alternanthera is a vibrant genus known for its striking foliage colors that range from deep purple to bright red. These plants are popular for adding bold contrast to garden beds or as colorful indoor accents. They thrive in warm, humid conditions and appreciate consistent moisture.

At a glance

Care level: Moderate
Plant type: Perennial
Light: Partial shade to full sun
Indoor light: Bright indirect
Water: Every 3 to 7 days
Mature size: 1 to 2 feet
Growth rate: Fast

Care

Keep the soil consistently moist but not waterlogged to prevent root issues. Watch for drooping leaves which signal the plant is thirsty. Provide plenty of bright light to maintain those intense leaf colors.

Watering: Keep the soil evenly moist at all times.
Feeding: Use a balanced liquid fertilizer during the active growing season.
Pruning: Trim back stems regularly to encourage a bushier shape.
Repotting: Move to a slightly larger pot when the roots fill the current container.
Soil: Well draining loamy soil
Soil pH: 6.0 to 7.0

Safety

Pets: This plant is generally considered non toxic to cats and dogs.

How to identify it

Opposite leaves on stems
Vibrant red or purple foliage
Small inconspicuous white flowers
Often low growing or spreading habit

Problems to watch for

By symptom

Plant problems by symptom

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Science

Family: Amaranthaceae
Genus: Alternanthera
Order: Caryophyllales
Class: Magnoliopsida

Taxonomy resolved against GBIF.

Keep your joyweed growing

This page is a general guide. Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked.

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This guide was generated with AI on October 28, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.