Sea Holly Plant Care
Eryngium maritimum L.
Updated · Sources · How we source care data
Eryngium maritimum, also called the sea holly, sea eryngo, or sea eryngium, is a perennial species of flowering plant in the carrot family Apiaceae, native to the coasts of most of Europe and the Mediterranean. Its prickly holly-like leaves and compact flower heads give it the appearance of a thistle.
Every 7–14 days
Full sun to partial shade
60–80°F
40–70%
At a glance
How do you care for Sea Holly?
Water Sea Holly every 7–14 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 Sea Holly Native To?
- Albania
- Algeria
- Austria
- Belarus
- Belgium
- Bosnia and Herzegovina
- Bulgaria
- Croatia
- Cyprus
- Czechia
- Denmark
- Egypt
- Estonia
- Finland
- France
- Germany
- Greece
- Hungary
- Iceland
- Ireland
- Israel
- Italy
- Latvia
- Lebanon
- Libya
- Lithuania
- Luxembourg
- Malta
- Moldova
- Montenegro
- Morocco
- North Macedonia
- Norway
- Poland
- Portugal
- Romania
- Russia
- Serbia
- Slovakia
- Slovenia
- Spain
- Sweden
- Switzerland
- Syria
- The Netherlands
- Tunisia
- Türkiye
- Ukraine
- United Kingdom
What Is the Sea Holly?
Sea Holly (Eryngium maritimum) belongs to the Apiaceae family within the Eryngium genus. Sea Holly is native to the coasts of most of Europe and the Mediterranean. Sea Holly is also known as Mediterranean Sea Holly.
Sea Holly displays an upright, clumping perennial growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Sea Holly produces small, cone-shaped blue or white flowers surrounded by spiky bracts.
Leaf size: approximately 6 inches.
How Often Should You Water a Sea Holly?
Eryngium maritimum requires watering every 7–14 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 7–14 days
Let soil partially dry between waterings
What Light Does the Sea Holly Need?
Sea Holly thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Sea Holly Prefer?
Eryngium maritimum grows best at temperatures of 60–80°F. Sea Holly prefers humidity levels of 40–70%.
Temperature
60–80°F
Humidity
40–70%
What Soil Mix Works Best for a Sea Holly?
Well-draining sandy soil with good organic content. Good drainage is essential for Sea Holly to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Sea Holly?
Feed Sea Holly 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 Sea Holly?
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 Sea Holly?
Sea Holly can be propagated through seeds, division of offsets. Similar propagation techniques also apply to alligator weed plant care, which shares the same genus.
Is the Sea Holly Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Sea Holly, 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 Sea Holly?
Sea Holly is susceptible to aphids, spider mites, powdery mildew. 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 Sea Holly Need?
Sea Holly grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Sea Holly is native to the coasts of most of Europe and the Mediterranean. In cooler regions, grow Sea Holly as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13a
Keep exploring plants
Sea Holly 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 Eryngium genus — compare its care with other Eryngium species on PlantoScan.
Eryngium is part of the Apiaceae plant family — browse all Apiaceae genera and species.
Sea Holly thrives in bright light and direct sun — see other bright-light plants.
More Eryngium Species
Other Eryngium species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Eryngium maritimum L., family Apiaceae (first published in Sp. Pl. : 233 (1753)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Sea Holly, 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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