Photo: Björn AppelCC BY-SA 3.0via Wikimedia Commonsresized / cropped
Chocolate Cosmos Plant Care
Cosmos atrosanguineus (Hook.) Voss
Updated · Sources · How we source care data
Cosmos atrosanguineus, the chocolate cosmos, is a species of Cosmos, native to Mexico. It has often been claimed that it is extinct in the wild; however it is "quite abundant" in Mexico. The species was introduced into cultivation in 1885, when the British seed company Thompson & Morgan first listed it in their seed catalogue. Its dark red to brownish red flowers have a scent resembling chocolate, which is one reason for its popularity as a cultivated plant.
Every 3–5 days
Full sun
50–80°F
40–60%
At a glance
How do you care for Chocolate Cosmos?
Water Chocolate Cosmos every 3–5 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 50–80°F (10–27°C) and 40–60% humidity. Fertilize it every 4 months during the growing season.
Where Is the Chocolate Cosmos Native To?
What Is the Chocolate Cosmos?
Chocolate Cosmos (Cosmos atrosanguineus) belongs to the Asteraceae family within the Cosmos genus. Chocolate Cosmos is native to Mexico. Chocolate Cosmos is also known as Black Cosmos, Bidens atrosanguinea, Cosmos diversifolius.
Chocolate Cosmos displays an upright, bushy annual growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Chocolate Cosmos produces colorful daisy-like flowers in shades of pink, white, and purple.
Leaf size: approximately 3 inches.
How Often Should You Water a Chocolate Cosmos?
Cosmos atrosanguineus 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 Chocolate Cosmos Need?
Chocolate Cosmos thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Chocolate Cosmos Prefer?
Cosmos atrosanguineus grows best at temperatures of 50–80°F. Chocolate Cosmos prefers humidity levels of 40–60%.
Temperature
50–80°F
Humidity
40–60%
What Soil Mix Works Best for a Chocolate Cosmos?
Well-draining, fertile soil with a mix of compost and sand. Good drainage is essential for Chocolate Cosmos to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Chocolate Cosmos?
Feed Chocolate Cosmos 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 Chocolate Cosmos?
Not applicable as an annual plant. 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 Chocolate Cosmos?
Chocolate Cosmos can be propagated through seeds. Similar propagation techniques also apply to cosmos plant care, which shares the same genus.
Is the Chocolate Cosmos Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Chocolate Cosmos, 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 Chocolate Cosmos?
Chocolate Cosmos 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 Chocolate Cosmos Need?
Chocolate Cosmos grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Chocolate Cosmos is native to Mexico. In cooler regions, grow Chocolate Cosmos as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Chocolate Cosmos 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 Cosmos genus — compare its care with other Cosmos species on PlantoScan.
Cosmos is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Chocolate Cosmos 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: Cosmos atrosanguineus (Hook.) Voss, family Asteraceae (first published in Vilm. Blumengärtn., ed. 3. 1: 485. 1894) — World Flora Online record, IPNI name record, Wikidata.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Chocolate Cosmos, 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: Björn Appel, CC BY-SA 3.0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 12a, 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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