Flattened whisk fern Plant Care

Flattened whisk fern (Psilotum complanatum) belongs to the Psilotaceae family within the Psilotum genus.

Flattened whisk fern displays a low, spreading fern-like growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Flattened whisk fern produces non-flowering.

Leaf size: approximately 6 inches.

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

Flattened whisk fern thrives in bright indirect light. Avoid placing Flattened whisk fern in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Psilotum complanatum tolerates temperatures of 60–80°F. Flattened whisk fern prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining sandy soil mix with high organic content. Good drainage is essential for Flattened whisk fern to prevent waterlogging, which leads to root rot and fungal issues.

Feed Flattened whisk fern every 8 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs 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 bright indirect light and well-draining sandy soil mix with high organic content. Avoid low spots where water collects after rain.

Flattened whisk fern is suited to USDA Zone 13a.

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

Flattened whisk fern can spread to about 1 ft (0.3 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.3 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 plant spacing calculator.

Prune Flattened whisk fern 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 shrub in one year.

Flattened whisk fern 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.

Flattened whisk fern can be propagated through spores, rhizomes. Similar propagation techniques also apply to whisk fern plant care, which shares the same genus.

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Flattened whisk fern is susceptible to mealybugs, scale insects. 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.

Flattened whisk fern grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. In cooler regions, grow Flattened whisk fern as a houseplant or bring it indoors before the first frost.