Plectranthus cremnus Plant Care
Plectranthus cremnus B.J.Conn
Updated · Sources · How we source care data
Coleus cremnus, synonym Plectranthus cremnus, is a rare herb only found in a few sites in the north coast of New South Wales. It occurs in shallow sandy soils in rocky coastal headlands such as Evans Head, Lennox Head and Sawtell.
Every 7–10 days
Bright indirect light
60–80°F
40–60%
At a glance
How do you care for Plectranthus cremnus?
Water Plectranthus cremnus every 7–10 days, letting the top layer of soil dry out between waterings, and give it bright indirect light. It prefers temperatures of 60–80°F (16–27°C) and 40–60% humidity. Fertilize it every 6 months during the growing season.
Where Is the Plectranthus cremnus Native To?
What Is the Plectranthus cremnus?
Plectranthus cremnus (Plectranthus cremnus) belongs to the Lamiaceae family within the Plectranthus genus. Plectranthus cremnus is native to a few sites in the north coast of New South Wales.
Plectranthus cremnus displays a bushy, spreading perennial growth habit, reaching up to 1.5 ft tall with a spread of approximately 2 ft. Plectranthus cremnus produces small, tubular flowers in shades of purple, pink, or white.
Leaf size: approximately 4 inches.
How Often Should You Water a Plectranthus cremnus?
Plectranthus cremnus 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 Plectranthus cremnus Need?
Plectranthus cremnus thrives in bright indirect light. Avoid placing Plectranthus cremnus in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Bright indirect light
What Temperature and Humidity Does the Plectranthus cremnus Prefer?
Plectranthus cremnus grows best at temperatures of 60–80°F. Plectranthus cremnus prefers humidity levels of 40–60%.
Temperature
60–80°F
Humidity
40–60%
What Soil Mix Works Best for a Plectranthus cremnus?
Well-draining soil mix with added perlite for good aeration. Good drainage is essential for Plectranthus cremnus to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Plectranthus cremnus?
Feed Plectranthus cremnus 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 Plectranthus cremnus?
Repot every 1-2 years in 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 Plectranthus cremnus?
Plectranthus cremnus can be propagated through stem cuttings, division. Similar propagation techniques also apply to moth orchid plant care, which shares the same genus.
Is the Plectranthus cremnus Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Plectranthus cremnus, 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 Plectranthus cremnus?
Plectranthus cremnus is susceptible to spider mites, mealybugs, aphids. 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 Plectranthus cremnus Need?
Plectranthus cremnus grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Plectranthus cremnus is native to a few sites in the north coast of New South Wales. In cooler regions, grow Plectranthus cremnus as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13a
Keep exploring plants
Plectranthus cremnus 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 Plectranthus genus — compare its care with other Plectranthus species on PlantoScan.
Plectranthus is part of the Lamiaceae plant family — browse all Lamiaceae genera and species.
Plectranthus cremnus thrives in bright light and direct sun — see other bright-light plants.
More Plectranthus Species
Other Plectranthus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Plectranthus cremnus B.J.Conn, family Lamiaceae (first published in Telopea 4: 643 (1992)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Plectranthus cremnus, 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 13a, 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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