Blue Tongue Plant Plant Care

Blue Tongue Plant (Indigastrum guerranum) belongs to the Fabaceae family within the Indigastrum genus. Blue Tongue Plant is native to Brazil, Colombia, Ecuador. Blue Tongue Plant is also known as Blue Star Fern.

Blue Tongue Plant displays a tall, upright shrub growth habit, reaching up to 5 ft tall with a spread of approximately 3 ft. Blue Tongue Plant produces clusters of small, fragrant white flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Blue Tongue Plant every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Blue Tongue Plant thrives in full sun to partial shade.

Indigastrum guerranum tolerates temperatures of 60–80°F. Blue Tongue Plant prefers humidity levels of 40–70%.

Well-draining loamy soil with added organic matter for nutrients. Good drainage is essential for Blue Tongue Plant to prevent waterlogging, which leads to root rot and fungal issues.

Feed Blue Tongue Plant every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining loamy soil with added organic matter for nutrients. Avoid low spots where water collects after rain.

Blue Tongue Plant is suited to USDA Zone 13a.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Blue Tongue Plant can spread to about 3 ft (0.9 m) and reach about 5 ft (2 m) tall. Space plants about 3 ft (0.9 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Blue Tongue Plant while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Blue Tongue Plant is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Blue Tongue Plant can be propagated through seeds, division of offsets. Similar propagation techniques also apply to silver bush plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Blue Tongue Plant is susceptible to aphids, whiteflies, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Blue Tongue Plant grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Blue Tongue Plant is native to Brazil, Colombia, Ecuador. In cooler regions, grow Blue Tongue Plant as a houseplant or bring it indoors before the first frost.