Photo: amantedarmaninCC BY 4.0via iNaturalistresized / cropped
Harlow's Turk's Cap Cactus Plant Care
Melocactus harlowii (Britton & Rose) Vaupel
Updated · Sources · How we source care data
Melocactus harlowii is a unique cactus species known for its striking bright pink flowers that bloom atop its cylindrical green stem. Originating from the dry forests of Brazil, this rare plant is popular among enthusiasts for its slow growth rate and distinctively ribbed appearance.
Every 14–21 days
Full sun
60–85°F
20–50%
At a glance
How do you care for Harlow's Turk's Cap Cactus?
Water Harlow's Turk's Cap Cactus every 14–21 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 60–85°F (16–29°C) and 20–50% humidity. Fertilize it every 8 months during the growing season.
Where Is the Harlow's Turk's Cap Cactus Native To?
What Is the Harlow's Turk's Cap Cactus?
Harlow's Turk's Cap Cactus (Melocactus harlowii) belongs to the Cactaceae family within the Melocactus genus. Harlow's Turk's Cap Cactus is native to Cuba.
Harlow's Turk's Cap Cactus displays a solitary or clustering globular stems growth habit, reaching up to 1.5 ft tall with a spread of approximately 1 ft. Harlow's Turk's Cap Cactus produces pink to red flowers that emerge from the top of the plant.
How Often Should You Water a Harlow's Turk's Cap Cactus?
Melocactus harlowii requires watering every 14–21 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 14–21 days
Let soil partially dry between waterings
What Light Does the Harlow's Turk's Cap Cactus Need?
Harlow's Turk's Cap Cactus thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Harlow's Turk's Cap Cactus Prefer?
Melocactus harlowii grows best at temperatures of 60–85°F. Harlow's Turk's Cap Cactus prefers humidity levels of 20–50%.
Temperature
60–85°F
Humidity
20–50%
What Soil Mix Works Best for a Harlow's Turk's Cap Cactus?
Sandy, well-draining cactus mix with perlite and coarse sand. Good drainage is essential for Harlow's Turk's Cap Cactus to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Harlow's Turk's Cap Cactus?
Feed Harlow's Turk's Cap Cactus every 8 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 8 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 Harlow's Turk's Cap Cactus?
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 Harlow's Turk's Cap Cactus?
Harlow's Turk's Cap Cactus can be propagated through seeds, offsets. Similar propagation techniques also apply to blue turk's cap cactus plant care, which shares the same genus.
Is the Harlow's Turk's Cap Cactus Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Harlow's Turk's Cap Cactus, 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 Harlow's Turk's Cap Cactus?
Harlow's Turk's Cap Cactus is susceptible to spider mites, scale insects. 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 Harlow's Turk's Cap Cactus Need?
Harlow's Turk's Cap Cactus grows outdoors in USDA Zone 10b – 11b. It survives winters down to planting zone 10b. Harlow's Turk's Cap Cactus is native to Cuba. In cooler regions, grow Harlow's Turk's Cap Cactus as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 10b – 11b
Keep exploring plants
Harlow's Turk's Cap Cactus 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 Melocactus genus — compare its care with other Melocactus species on PlantoScan.
Melocactus is part of the Cactaceae plant family — browse all Cactaceae genera and species.
Harlow's Turk's Cap Cactus thrives in bright light and direct sun — see other bright-light plants.
More Melocactus Species
Other Melocactus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Melocactus harlowii (Britton & Rose) Vaupel, family Cactaceae (first published in in Monatsschr. Kakteenk. 22: 66. 1912.) — World Flora Online record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Harlow's Turk's Cap Cactus, 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: amantedarmanin, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 10b – 11b, 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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