Photo: sarefoCC BY-SA 3.0via Wikimedia Commonsresized / cropped
Smallflower Cosmos Plant Care
Cosmos parviflorus (Jacq.) Pers.
Updated · Sources · How we source care data
Cosmos parviflorus is a North American species of plants in the family Asteraceae. Common names include southwestern cosmos in the US and juve or aceitilla blanca in Mexico. In many places it is a common weed in agricultural fields, although it also grows in grassy meadows in forested areas. The species appears to be native in Texas, New Mexico, Colorado, Arizona, and Utah. Collections have also been made from Massachusetts, Maine, Maryland, Missouri, Rhode Island, although it appears to be introduced to those regions. It is widespread in Mexico from Chihuahua to Oaxaca.
Every 3–5 days
Full sun
50–80°F
40–60%
At a glance
How do you care for Smallflower Cosmos?
Water Smallflower 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 Smallflower Cosmos Native To?
What Is the Smallflower Cosmos?
Smallflower Cosmos (Cosmos parviflorus) belongs to the Asteraceae family within the Cosmos genus. Smallflower Cosmos is native to parts of the Southwestern United States and most of Mexico and appears to be introduced in portions of the Northeastern United States. Smallflower Cosmos is also known as Cosmus, Cosmos parviflorus.
Smallflower Cosmos displays an upright, bushy annual growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Smallflower Cosmos produces colorful daisy-like flowers in shades of pink, white, and purple.
Leaf size: approximately 3 inches.
How Often Should You Water a Smallflower Cosmos?
Cosmos parviflorus 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 Smallflower Cosmos Need?
Smallflower Cosmos thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Smallflower Cosmos Prefer?
Cosmos parviflorus grows best at temperatures of 50–80°F. Smallflower Cosmos prefers humidity levels of 40–60%.
Temperature
50–80°F
Humidity
40–60%
What Soil Mix Works Best for a Smallflower Cosmos?
Well-draining, fertile soil with a mix of compost and sand. Good drainage is essential for Smallflower Cosmos to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Smallflower Cosmos?
Feed Smallflower 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 Smallflower 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 Smallflower Cosmos?
Smallflower Cosmos can be propagated through seeds. Similar propagation techniques also apply to chocolate cosmos plant care, which shares the same genus.
Is the Smallflower Cosmos Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Smallflower 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 Smallflower Cosmos?
Smallflower 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 Smallflower Cosmos Need?
Smallflower Cosmos grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Smallflower Cosmos is native to parts of the Southwestern United States and most of Mexico and appears to be introduced in portions of the Northeastern United States. In cooler regions, grow Smallflower Cosmos as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Smallflower 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.
Smallflower Cosmos thrives in bright light and direct sun — see other bright-light plants.
More Cosmos Species
Other Cosmos species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Cosmos parviflorus (Jacq.) Pers., family Asteraceae (first published in 477 1807) — World Flora Online record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Smallflower 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: sarefo, 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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