Photo: Walter SiegmundCC BY-SA 3.0via Wikimedia Commonsresized / cropped
Long Agoseris Plant Care
Agoseris longula Greene
Updated · Sources · How we source care data
This plant's long, slender leaves are its most distinctive visual feature, making it stand out in any garden. Originating from the western United States, Agoseris longula is highly sought after by plant collectors for its unique appearance and ability to thrive in various growing conditions. Its delicate yellow flowers add a pop of color to any landscape.
Every 7–14 days
Full sun to partial shade
65–75°F
40–60%
At a glance
How do you care for Long Agoseris?
Water Long Agoseris every 7–14 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 65–75°F (18–24°C) and 40–60% humidity. Fertilize it every 2 months during the growing season.
Where Is the Long Agoseris Native To?
What Is the Long Agoseris?
Long Agoseris (Agoseris longula) belongs to the Asteraceae family within the Agoseris genus. Long Agoseris is native to western North America. Long Agoseris is also known as Long False Dandelion, Agoseris lacera, Agoseris lapathifolia.
Long Agoseris displays a low rosette, clumping growth habit, reaching up to 1 ft tall with a spread of approximately . Long Agoseris produces bright yellow daisy-like flowers.
Leaf size: approximately 3 inches.
How Often Should You Water a Long Agoseris?
Agoseris longula requires watering every 7–14 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 7–14 days
Let soil partially dry between waterings
What Light Does the Long Agoseris Need?
Long Agoseris thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Long Agoseris Prefer?
Agoseris longula grows best at temperatures of 65–75°F. Long Agoseris prefers humidity levels of 40–60%.
Temperature
65–75°F
Humidity
40–60%
What Soil Mix Works Best for a Long Agoseris?
Well-draining sandy soil with some organic matter. Good drainage is essential for Long Agoseris to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Long Agoseris?
Feed Long Agoseris every 2 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 2 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 Long Agoseris?
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 Long Agoseris?
Long Agoseris can be propagated through seeds, division of root clumps. Similar propagation techniques also apply to false dandelion plant care, which shares the same genus.
Is the Long Agoseris Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Long Agoseris, 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 Long Agoseris?
Long Agoseris 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.
Keep exploring plants
Long Agoseris 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 Agoseris genus — compare its care with other Agoseris species on PlantoScan.
Agoseris is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Long Agoseris 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: Agoseris longula Greene, family Asteraceae (first published in Leafl. Bot. Observ. Crit. 2: 125 (-126) (1911)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Long Agoseris, 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: Walter Siegmund, CC BY-SA 3.0, Wikimedia Commons — original.
- 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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