Tall dock Plant Care
Lapathum altissimum Nieuwl.
Updated · Sources · How we source care data
This plant, with its long, lance-shaped leaves that are a striking silver color, hails from the Mediterranean region. Plant collectors covet Lapathum altissimum for its unique foliage that adds a touch of elegance and sophistication to any garden or collection.
Every 7–10 days
Full sun to partial shade
60–80°F
50–70%
At a glance
How do you care for Tall dock?
Water Tall dock every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–80°F (16–27°C) and 50–70% humidity. Fertilize it every month during the growing season.
Where Is the Tall dock Native To?
What Is the Tall dock?
Tall dock (Lapathum altissimum) belongs to the Polygonaceae family within the Lapathum genus. Tall dock is native to southern Ontario, the United States east of the Rockies, and northern Mexico. Tall dock is also known as Pale smartweed, Pale lapathum.
Tall dock displays a spreading ground cover growth habit, reaching up to 4 ft tall with a spread of approximately 2 ft. Tall dock produces small clusters of inconspicuous flowers.
Leaf size: approximately 6 inches.
How Often Should You Water a Tall dock?
Lapathum altissimum requires watering every 7–10 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 7–10 days
Let soil partially dry between waterings
What Light Does the Tall dock Need?
Tall dock thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Tall dock Prefer?
Lapathum altissimum grows best at temperatures of 60–80°F. Tall dock prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–80°F
Humidity
50–70%
What Soil Mix Works Best for a Tall dock?
Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Tall dock to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Tall dock?
Feed Tall dock every month 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 month
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Tall dock?
Repot every 2-3 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 Tall dock?
Tall dock can be propagated through seeds, division of root clumps.
Is the Tall dock Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Tall dock, 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 Tall dock?
Tall dock is susceptible to aphids, leaf miners, powdery mildew. 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 Tall dock Need?
Tall dock grows outdoors in USDA Zone 4a – 9b. It survives winters down to planting zone 4a. Tall dock is native to southern Ontario, the United States east of the Rockies, and northern Mexico.
Hardiness Zone
Zone 4a – 9b
Keep exploring plants
Tall dock 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 Lapathum genus (family Polygonaceae) — search all Lapathum species in the plant lookup.
Tall dock thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Lapathum altissimum Nieuwl., family Polygonaceae (first published in Amer. Midl. Naturalist 3: 237 (1914)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Tall dock, 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.
- Hardiness zone: USDA Zone 4a – 9b, estimated from the plant's typical growing conditions.
- 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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