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Large-flowered Hemp-nettle Plant Care
Galeopsis speciosa Mill.
Updated · Sources · How we source care data
This plant's striking yellow-green leaves with deep purple veins make it a standout in any garden. Hailing from Europe and Asia, its unique appearance and ability to attract pollinators make it a sought-after addition for plant collectors looking to add variety to their collection.
Every 4–7 days
Full sun to partial shade
60–75°F
50–70%
At a glance
How do you care for Large-flowered Hemp-nettle?
Water Large-flowered Hemp-nettle every 4–7 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–75°F (16–24°C) and 50–70% humidity. Fertilize it every month during the growing season.
Where Is the Large-flowered Hemp-nettle Native To?
What Is the Large-flowered Hemp-nettle?
Large-flowered Hemp-nettle (Galeopsis speciosa) belongs to the Lamiaceae family within the Galeopsis genus. Large-flowered Hemp-nettle is native to northern and central Europe and Siberia. Large-flowered Hemp-nettle is also known as Large Flowered Hemp Nettle.
Large-flowered Hemp-nettle displays a spreading herbaceous perennial growth habit, reaching up to 2 ft tall with a spread of approximately 1 ft. Large-flowered Hemp-nettle produces small, tubular purple flowers in dense spikes.
Leaf size: approximately 3 inches.
How Often Should You Water a Large-flowered Hemp-nettle?
Galeopsis speciosa requires watering every 4–7 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 4–7 days
Let soil partially dry between waterings
What Light Does the Large-flowered Hemp-nettle Need?
Large-flowered Hemp-nettle thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Large-flowered Hemp-nettle Prefer?
Galeopsis speciosa grows best at temperatures of 60–75°F. Large-flowered Hemp-nettle prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–75°F
Humidity
50–70%
What Soil Mix Works Best for a Large-flowered Hemp-nettle?
Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Large-flowered Hemp-nettle to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Large-flowered Hemp-nettle?
Feed Large-flowered Hemp-nettle 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 Large-flowered Hemp-nettle?
Divide and 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 Large-flowered Hemp-nettle?
Large-flowered Hemp-nettle can be propagated through seeds, division of clumps. Similar propagation techniques also apply to red hemp-nettle plant care, which shares the same genus.
Is the Large-flowered Hemp-nettle Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Large-flowered Hemp-nettle, 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 Large-flowered Hemp-nettle?
Large-flowered Hemp-nettle is susceptible to aphids, spider mites, whiteflies. 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 Large-flowered Hemp-nettle Need?
Large-flowered Hemp-nettle grows outdoors in USDA Zone 3a – 8b. It survives winters down to planting zone 3a. Large-flowered Hemp-nettle is native to northern and central Europe and Siberia.
Hardiness Zone
Zone 3a – 8b
Keep exploring plants
Large-flowered Hemp-nettle 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 Galeopsis genus — compare its care with other Galeopsis species on PlantoScan.
Galeopsis is part of the Lamiaceae plant family — browse all Lamiaceae genera and species.
Large-flowered Hemp-nettle 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: Galeopsis speciosa Mill., family Lamiaceae (first published in Gard. Dict. ed. 8 : n.º 3 (1768)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Large-flowered Hemp-nettle, 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: AI-generated illustration (labelled on the image).
- Hardiness zone: USDA Zone 3a – 8b, 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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