Shore Quillwort Plant Care

Shore Quillwort (Isoetes maritima) belongs to the Isoetaceae family within the Isoetes genus. Shore Quillwort is native to Alaska, British Columbia, and Washington state.

Shore Quillwort displays a low rosette, compact growth habit, reaching up to 0.5 ft tall with a spread of approximately 0.5 ft. Shore Quillwort produces small inconspicuous flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Shore Quillwort every 7–14 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.

Shore Quillwort thrives in full sun to partial shade.

Isoetes maritima tolerates temperatures of 60–80°F. Shore Quillwort prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Sandy, acidic soil with good drainage. Good drainage is essential for Shore Quillwort to prevent waterlogging, which leads to root rot and fungal issues.

Feed Shore Quillwort every month 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 full sun to partial shade and sandy, acidic soil with good drainage. Avoid low spots where water collects after rain.

Shore Quillwort is suited to USDA Zone 4a – 8b.

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.

Shore Quillwort can spread to about 1 ft (0.2 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.2 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 Shore Quillwort 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.

Shore Quillwort is hardy down to USDA zone 4a, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.

Shore Quillwort can be propagated through spores, division of rhizomes. Similar propagation techniques also apply to alpine quillwort plant care, which shares the same genus.

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Shore Quillwort is susceptible to aphids, 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.

Shore Quillwort grows outdoors in USDA Zone 4a – 8b. It survives winters down to planting zone 4a. Shore Quillwort is native to Alaska, British Columbia, and Washington state.