Marsh Lousewort (Pedicularis palustris)

Photo: Marek HrušovskýCC BY 4.0via iNaturalistresized / cropped

Marsh Lousewort Plant Care

Pedicularis palustris L.

Updated · Sources · How we source care data

This plant's bright yellow, tube-shaped flowers set atop slender stems are a striking visual feature. Originating from wetlands in Europe and Asia, Pedicularis palustris is sought after by plant collectors for its unique appearance and ability to attract pollinators with its nectar-filled blooms.

Water

Every 5–7 days

Light

Partial shade to full sun

Temp

50–75°F

Humidity

40–60%

At a glance

How do you care for Marsh Lousewort?

Water Marsh Lousewort every 5–7 days, letting the top layer of soil dry out between waterings, and give it partial shade to full sun. It prefers temperatures of 50–75°F (10–24°C) and 40–60% humidity. Fertilize it every 6 months during the growing season.

Where Is the Marsh Lousewort Native To?

Native range16 countries

What Is the Marsh Lousewort?

Marsh Lousewort (Pedicularis palustris) belongs to the Orobanchaceae family within the Pedicularis genus. Marsh Lousewort is native to central and northern Europe and Asia. Marsh Lousewort is also known as Greater Lousewort.

Marsh Lousewort displays a clumping herbaceous perennial growth habit, reaching up to 1.5 ft tall with a spread of approximately 1 ft. Marsh Lousewort produces tubular flowers in shades of pink, purple, or white.

Leaf size: approximately 4 inches.

How Often Should You Water a Marsh Lousewort?

Pedicularis palustris requires watering every 5–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.

Watering Frequency

Every 5–7 days

Let soil partially dry between waterings

What Light Does the Marsh Lousewort Need?

Marsh Lousewort thrives in partial shade to full sun.

Light Requirement

Partial shade to full sun

What Temperature and Humidity Does the Marsh Lousewort Prefer?

Pedicularis palustris grows best at temperatures of 50–75°F. Marsh Lousewort prefers humidity levels of 40–60%.

Temperature

50–75°F

Humidity

40–60%

What Soil Mix Works Best for a Marsh Lousewort?

Well-draining, slightly acidic soil with good organic content. Good drainage is essential for Marsh Lousewort to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Marsh Lousewort?

Feed Marsh Lousewort every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.

Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.

Fertilizing

Every 6 months

During the growing season

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

How Do You Repot a Marsh Lousewort?

Repot every 1-2 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.

How Do You Propagate a Marsh Lousewort?

Marsh Lousewort can be propagated through seeds, division. Similar propagation techniques also apply to wood betony plant care, which shares the same genus.

Is the Marsh Lousewort Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Marsh Lousewort, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.

This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.

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

What Pests and Diseases Affect the Marsh Lousewort?

Marsh Lousewort is susceptible to aphids, 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.

What USDA Hardiness Zone Does the Marsh Lousewort Need?

Marsh Lousewort grows outdoors in USDA Zone 12a – 8b. It survives winters down to planting zone 12a. Marsh Lousewort is native to central and northern Europe and Asia. In cooler regions, grow Marsh Lousewort as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 12a – 8b

Keep exploring plants

Marsh Lousewort is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.

It belongs to the Pedicularis genus — compare its care with other Pedicularis species on PlantoScan.

Pedicularis is part of the Orobanchaceae plant family — browse all Orobanchaceae genera and species.

Marsh Lousewort thrives in bright light and direct sun — see other bright-light plants.

More Pedicularis Species

Other Pedicularis species in PlantoScan's care catalogue share similar watering, light, and soil preferences:

Sources

  • Scientific name & taxonomy: Pedicularis palustris L., family Orobanchaceae (first published in Sp. Pl. : 607 (1753)) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Marsh Lousewort, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
  • Photo: Marek Hrušovský, CC BY 4.0, iNaturalist — original.
  • Hardiness zone: USDA Zone 12a – 8b, calculated from the plant's minimum temperature.
  • Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.

Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.

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