Photo: Salvör GissurardóttirPublic domainvia Wikimedia Commons
Spiniest Thistle Plant Care
Cnicus spinosissimus L.
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 to partial shade
60–80°F
40–70%
At a glance
How do you care for Spiniest Thistle?
Water Spiniest Thistle every 7–10 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 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Spiniest Thistle Native To?
What Is the Spiniest Thistle?
Spiniest Thistle (Cnicus spinosissimus) belongs to the Asteraceae family within the Cnicus genus. Spiniest Thistle is native to France, Italy, Germany, Switzerland, Austria, and the Balkans. Spiniest Thistle is also known as Most Spiny Thistle, Cnicus spinosissimus, Cirsium spinosissimum.
Spiniest Thistle displays an upright, branching perennial growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Spiniest Thistle produces small, tubular purple flowers in dense clusters.
Leaf size: approximately 6 inches.
How Often Should You Water a Spiniest Thistle?
Cnicus spinosissimus 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 Spiniest Thistle Need?
Spiniest Thistle thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Spiniest Thistle Prefer?
Cnicus spinosissimus grows best at temperatures of 60–80°F. Spiniest Thistle prefers humidity levels of 40–70%.
Temperature
60–80°F
Humidity
40–70%
What Soil Mix Works Best for a Spiniest Thistle?
Well-draining sandy loam with added organic matter. Good drainage is essential for Spiniest Thistle to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Spiniest Thistle?
Feed Spiniest Thistle 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 Spiniest Thistle?
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 Spiniest Thistle?
Spiniest Thistle can be propagated through seeds, division of root ball.
Is the Spiniest Thistle Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Spiniest Thistle, 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 Spiniest Thistle?
Spiniest Thistle is susceptible to aphids, caterpillars, 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 Spiniest Thistle Need?
Spiniest Thistle grows outdoors in USDA Zone 4a – 7b. It survives winters down to planting zone 4a. Spiniest Thistle is native to France, Italy, Germany, Switzerland, Austria, and the Balkans.
Hardiness Zone
Zone 4a – 7b
Keep exploring plants
Spiniest Thistle 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 Cnicus genus (family Asteraceae) — search all Cnicus species in the plant lookup.
Spiniest Thistle 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: Cnicus spinosissimus L., family Asteraceae (first published in Sp. Pl. : 826 (1753)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Spiniest Thistle, 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 4a – 7b, 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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