Rock Samphire Plant Care
Crithmum maritimum L.
Updated · Sources · How we source care data
Crithmum is a monospecific genus of flowering plant in the carrot family, Apiaceae. The sole species, Crithmum maritimum, is commonly known as rock samphire, sea fennel or samphire.
Every 7–10 days
Full sun to partial shade
50–75°F
40–70%
At a glance
How do you care for Rock Samphire?
Water Rock Samphire 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 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
What Is the Rock Samphire?
Rock Samphire (Crithmum maritimum) belongs to the Apiaceae family within the Crithmum genus. Rock Samphire is native to parts of the Old World. Rock Samphire is also known as Sea Fennel, Samphire.
Rock Samphire displays a low-spreading perennial growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Rock Samphire produces small white or yellow umbel flowers.
Leaf size: approximately 2 inches.
How Often Should You Water a Rock Samphire?
Crithmum maritimum 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 Rock Samphire Need?
Rock Samphire thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Rock Samphire Prefer?
Crithmum maritimum grows best at temperatures of 50–75°F. Rock Samphire prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Rock Samphire?
Well-draining sandy soil with good organic content. Good drainage is essential for Rock Samphire to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Rock Samphire?
Feed Rock Samphire 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 Rock Samphire?
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 Rock Samphire?
Rock Samphire can be propagated through seeds, division.
Is the Rock Samphire Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Rock Samphire, 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 Rock Samphire?
Rock Samphire 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 Rock Samphire Need?
Rock Samphire grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Rock Samphire is native to parts of the Old World. In cooler regions, grow Rock Samphire as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Rock Samphire 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 Crithmum genus — compare its care with other Crithmum species on PlantoScan.
Crithmum is part of the Apiaceae plant family — browse all Apiaceae genera and species.
Rock Samphire 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: Crithmum maritimum L., family Apiaceae (first published in Sp. Pl. : 246 (1753)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Rock Samphire, 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 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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