Cosmos Plant Care

Cosmos caudatus Kunth

Updated · Sources · How we source care data

Cosmos caudatus or king's salad is an annual plant in the genus Cosmos, bearing purple, pink, or white ray florets. It is native to Latin America, and the West Indies, though naturalized in tropical parts of Asia, Africa, and Australia.

🌱Herbs🌼Perennials🌻Annuals
Water

Every 3–5 days

Light

Full sun

Temp

50–80°F

Humidity

40–60%

At a glance

How do you care for Cosmos?

Water 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 Cosmos Native To?

Native range22 countries

What Is the Cosmos?

Cosmos (Cosmos caudatus) belongs to the Asteraceae family within the Cosmos genus. Cosmos is native to Latin America, and the West Indies. Cosmos is also known as King Cosmos, Wild Cosmos, Ulam Raja.

Cosmos displays an upright, bushy annual growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Cosmos produces colorful daisy-like flowers in shades of pink, white, and purple.

Leaf size: approximately 3 inches.

How Often Should You Water a Cosmos?

Cosmos caudatus 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 Need?

Cosmos thrives in full sun.

Light Requirement

Full sun

What Temperature and Humidity Does the Cosmos Prefer?

Cosmos caudatus grows best at temperatures of 50–80°F. Cosmos prefers humidity levels of 40–60%.

Temperature

50–80°F

Humidity

40–60%

What Soil Mix Works Best for a Cosmos?

Well-draining, fertile soil with a mix of compost and sand. Good drainage is essential for Cosmos to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Cosmos?

Feed 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 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 Cosmos?

Cosmos can be propagated through seeds. Similar propagation techniques also apply to cosmos plant care, which shares the same genus.

Is the Cosmos Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list 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 Cosmos?

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 Cosmos Need?

Cosmos grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Cosmos is native to Latin America, and the West Indies. In cooler regions, grow Cosmos as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 12a

Keep exploring plants

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.

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 caudatus Kunth, family Asteraceae (first published in Nova Genera et Species Plantarum 4 1820) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list 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.
  • 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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