Photo: David Eickhoff from Pearl City, Hawaii, USACC BY 2.0via Wikimedia Commonsresized / cropped
Cosmos Bidens Plant Care
Bidens cosmoides Sherff
Updated · Sources · How we source care data
With its unique fern-like leaves that are a striking shade of lime green, this plant originated from the wetlands of North and South America. Plant collectors are drawn to Bidens cosmoides for its delicate appearance and ability to attract butterflies and pollinators to the garden.
Every 3–5 days
Full sun to partial shade
60–80°F
40–60%
At a glance
How do you care for Cosmos Bidens?
Water Cosmos Bidens every 3–5 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 40–60% humidity. Fertilize it every 4 months during the growing season.
Where Is the Cosmos Bidens Native To?
What Is the Cosmos Bidens?
Cosmos Bidens (Bidens cosmoides) belongs to the Asteraceae family within the Bidens genus. Cosmos Bidens is native to mixed mesic forests at elevations of 2,000–3,000 ft (610–910 m) on the island of Kauaʻi in Hawaii. Cosmos Bidens is also known as Bidens cosmoides.
Cosmos Bidens displays an upright, branching annual growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Cosmos Bidens produces small, daisy-like flowers in shades of yellow, orange, or white.
Leaf size: approximately 2 inches.
How Often Should You Water a Cosmos Bidens?
Bidens cosmoides requires watering every 3–5 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 3–5 days
Let soil partially dry between waterings
What Light Does the Cosmos Bidens Need?
Cosmos Bidens thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Cosmos Bidens Prefer?
Bidens cosmoides grows best at temperatures of 60–80°F. Cosmos Bidens prefers humidity levels of 40–60%.
Temperature
60–80°F
Humidity
40–60%
What Soil Mix Works Best for a Cosmos Bidens?
Well-draining soil with high organic content, such as loam or sandy loam. Good drainage is essential for Cosmos Bidens to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Cosmos Bidens?
Feed Cosmos Bidens every 4 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 4 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 Cosmos Bidens?
Annually in 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 Cosmos Bidens?
Cosmos Bidens can be propagated through seeds. Similar propagation techniques also apply to spanish needles plant care, which shares the same genus.
Is the Cosmos Bidens Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Cosmos Bidens, 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 Cosmos Bidens?
Cosmos Bidens 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 Cosmos Bidens Need?
Cosmos Bidens grows outdoors in USDA Zone 10b – 11b. It survives winters down to planting zone 10b. Cosmos Bidens is native to mixed mesic forests at elevations of 2,000–3,000 ft (610–910 m) on the island of Kauaʻi in Hawaii. In cooler regions, grow Cosmos Bidens as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 10b – 11b
Keep exploring plants
Cosmos Bidens 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 Bidens genus — compare its care with other Bidens species on PlantoScan.
Bidens is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Cosmos Bidens thrives in bright light and direct sun — see other bright-light plants.
More Bidens Species
Other Bidens species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Bidens cosmoides Sherff, family Asteraceae (first published in Bot. Gaz. 70: 98 (1920)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Cosmos Bidens, 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: David Eickhoff from Pearl City, Hawaii, USA, CC BY 2.0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 10b – 11b, 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.
Identify Plants Like the
Cosmos Bidens Instantly
Scan any plant with your phone camera and get instant ID, care tips, water and fertilizer reminders, and health checks — all in one app.
Free
to download
iOS & Android
platforms
Light & dark
mode
100,000+
species