Photo: Salvör GissurardóttirPublic domainvia Wikimedia Commons
Cnicus spinosissimus Plant Care
Carduus comosus Lam.
Updated · Sources · How we source care data
Cirsium spinosissimum, common name spiniest thistle, is a European species of thistle which grows in dry rocky areas. It is found in France, Italy, Germany, Switzerland, Austria, and the Balkans.
Every 7–10 days
Full sun
60–80°F
40–70%
At a glance
How do you care for Cnicus spinosissimus?
Water Cnicus spinosissimus every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 60–80°F (16–27°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Cnicus spinosissimus Native To?
What Is the Cnicus spinosissimus?
Cnicus spinosissimus (Carduus comosus) belongs to the Asteraceae family within the Carduus genus. Cnicus spinosissimus is native to France, Italy, Germany, Switzerland, Austria, and the Balkans. Cnicus spinosissimus is also known as Cirsium spinosissimum, Carduus spinosissimus, Carduus comosus.
Cnicus spinosissimus displays an upright, branching perennial growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Cnicus spinosissimus produces purple, pink, or white thistle-like flowers in dense clusters.
Leaf size: approximately 8 inches.
How Often Should You Water a Cnicus spinosissimus?
Carduus comosus requires watering every 7–10 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 7–10 days
Let soil partially dry between waterings
What Light Does the Cnicus spinosissimus Need?
Cnicus spinosissimus thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Cnicus spinosissimus Prefer?
Carduus comosus grows best at temperatures of 60–80°F. Cnicus spinosissimus prefers humidity levels of 40–70%.
Temperature
60–80°F
Humidity
40–70%
What Soil Mix Works Best for a Cnicus spinosissimus?
Well-draining sandy loam with added organic matter. Good drainage is essential for Cnicus spinosissimus to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Cnicus spinosissimus?
Feed Cnicus spinosissimus every 6 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 6 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 Cnicus spinosissimus?
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 Cnicus spinosissimus?
Cnicus spinosissimus can be propagated through seeds. Similar propagation techniques also apply to thistle plant care, which shares the same genus.
Is the Cnicus spinosissimus Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Cnicus spinosissimus, 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 Cnicus spinosissimus?
Cnicus spinosissimus is susceptible to aphids, thrips, spider mites. 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 Cnicus spinosissimus Need?
Cnicus spinosissimus grows outdoors in USDA Zone 5a – 8b. It survives winters down to planting zone 5a. Cnicus spinosissimus is native to France, Italy, Germany, Switzerland, Austria, and the Balkans.
Hardiness Zone
Zone 5a – 8b
Keep exploring plants
Cnicus spinosissimus 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 Carduus genus — compare its care with other Carduus species on PlantoScan.
Carduus is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Cnicus spinosissimus 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: Carduus comosus Lam., family Asteraceae (first published in Encycl. 1: 703 (1785)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Cnicus spinosissimus, 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: Salvör Gissurardóttir, Public domain, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 5a – 8b, 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.
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