How to care for Stromanthe thalia

Stromanthe thalia · Triostar, Calathea Triostar

Stromanthe (Stromanthe thalia) — an upright evergreen perennial from Brazilian rain forest, usually 60–90 cm tall indoors, with lance-shaped olive-green leaves variegated cream and pink and vivid pink beneath; the leaves fold up at night. Stromanthe needs partial shade and 16–21 °C. Water it about every 5 days while it grows and about every 8 days in the winter rest.

Updated: November 4, 2026

Watering and repotting stromanthe through the year

It lives indoors all year, so it has no sowing or planting dates: it grows from March to September and rests from October to February (the other way round in the southern hemisphere).

Repot it about every 36 months.

When to plant stromanthe?

Plant or repot stromanthe in spring, as it starts into growth; early to midsummer also works. It is a houseplant, so it has no outdoor planting date and no frost decides it: just avoid autumn and winter, when growth slows and fresh compost stays wet too long. After that, move it to a slightly larger pot about every three years, or sooner once roots circle the pot or grow through the drainage holes.

Watering in the growing and resting halves of the year: Watering and repotting stromanthe through the year.

Sources: RHS: How to repot a plant · Penn State Extension: Repotting houseplants

Quick facts

Type	Houseplant
Latin name	Stromanthe thalia
Family	Marantaceae
Also called	Triostar, Calathea Triostar
Light	Partial shade
Frost	does not tolerate frost
Repotting	every 36 months
Grown in	At home

Stromanthe care by growth stage

At home

Stage	Watering	Temperature	Feeding
Growth	every 5 days	16…21 °C	balanced (NPK), 14 days into the stage; balanced (NPK), 35 days into the stage; balanced (NPK), 56 days into the stage; balanced (NPK), 77 days into the stage; balanced (NPK), 98 days into the stage; balanced (NPK), 119 days into the stage; balanced (NPK), 140 days into the stage; balanced (NPK), 161 days into the stage
Winter rest	every 8 days	—	—

Growing notes

Light

Bright filtered light or partial shade, for example by an east or north window. Direct sun scorches the leaves.

Soil

Peat-free potting compost that stays moist but drains well; it prefers acidic to neutral soil.

Care

Water freely while it grows and more moderately in winter; it does not tolerate dry soil, but overwatering brings root and stem rot. It wants warmth of 16–21 °C and high humidity, from a humidifier or a tray of moist pebbles; brown leaf tips mean dry air. Use rainwater or tap water left to stand for 24 hours. Every 2 or 3 weeks while it is growing, give a low-nitrogen liquid fertiliser. White flowers with orange sepals and red bracts may appear in winter and spring. No pruning is needed. Divide the clump in spring, before new growth starts; otherwise it only needs repotting every few years, once the clump has filled the pot. Watch for mealybugs, aphids and spider mites.

Pests and diseases of Stromanthe

1 problem is recorded for stromanthe; it has a page with symptoms, treatment and prevention.

Pests

Two-spotted spider mite

Other plants of the Marantaceae family

Stromanthe belongs to Marantaceae; 3 other plants of this family have a guide here.

Plant lists it is in

Part of: Houseplants · Houseplants you rarely repot · Thirsty houseplants

Sources

Figures checked against these sources.