Sea Holly (Eryngium Planum ‘White Glitter’)

Plant: Table of Contents

Understanding Sea Holly (Eryngium Planum ‘White Glitter’): A Comprehensive Guide


The sea holly, scientifically known as Eryngium planum ‘White Glitter’, is a fascinating plant that has been captivating gardeners and botanists for centuries. With its striking foliage and unique appearance, the sea holly is a popular choice for both ornamental and practical purposes. In this comprehensive guide, we will explore the cultural significance, uses, care requirements, and propagation techniques for the sea holly. Additionally, we will delve into common diseases and pests that affect this plant, along with botanist’s tips and interesting fun facts. Whether you are a seasoned gardener or a novice plant enthusiast, this guide will provide you with valuable insights into the world of sea holly and how to cultivate and appreciate this remarkable plant.

What is Sea Holly – Eryngium Planum ‘White Glitter’?

Sea holly, or Eryngium planum ‘White Glitter’, is a perennial plant that belongs to the Apiaceae family. This family is known for its diverse range of plants, which includes common vegetables such as carrots and celery, as well as various flowering plants. The sea holly is native to Europe and is characterized by its spiky foliage and cone-shaped flower heads. The unique appearance of the sea holly makes it a popular choice for gardeners looking to add texture and visual interest to their landscapes.

Key Takeaways – Sea Holly (Eryngium Planum ‘White Glitter’)

Before delving into the specific aspects of sea holly care and cultivation, let’s summarize some key takeaways about this intriguing plant:

  • Sea holly (Eryngium planum ‘White Glitter’) is a perennial plant with spiky foliage and cone-shaped flower heads.
  • It is a member of the Apiaceae family and is native to Europe.
  • The plant is prized for its unique appearance, making it a popular choice for ornamental gardens.
  • Sea holly is versatile and can be used in various landscaping designs, from coastal gardens to rock gardens.
  • It is drought tolerant and attracts pollinators, making it an environmentally valuable addition to any garden.

Now that we have a broad understanding of sea holly, let’s delve into the specific aspects of its culture, uses, and care requirements.



Sea holly is a hardy plant that is well adapted to dry and drought-prone conditions. Once established, it requires minimal supplemental watering, making it an ideal choice for water-wise gardens and landscapes. However, during the initial stages of planting or in prolonged periods of drought, regular watering is beneficial to help the plant establish a strong root system. It is essential to ensure that the soil has good drainage to avoid waterlogged conditions, which can be detrimental to the sea holly.


In terms of sunlight requirements, sea holly thrives in full sun. It requires at least 6-8 hours of direct sunlight per day to encourage healthy growth and the development of vibrant flower heads. When planted in partial shade, the plant may become leggy and produce fewer flowers. Therefore, it is best to select a location in the garden that receives ample sunlight for the majority of the day if you want to cultivate sea holly successfully.


Sea holly is not an overly demanding plant when it comes to fertilization. In fact, excessive fertilization can lead to lush foliage growth at the expense of flower production. A light application of a balanced, slow-release fertilizer in early spring is generally sufficient to provide the plant with the nutrients it needs for the growing season. It is crucial to avoid high-nitrogen fertilizers, as they can promote excessive vegetative growth and detract from the sea holly’s unique visual appeal.


The sea holly thrives in well-drained, sandy or loamy soil with a slightly alkaline to neutral pH. The plant is well adapted to harsh, dry conditions, so it is essential to avoid waterlogged or heavy clay soils, as they can lead to root rot and other issues. If necessary, amending the soil with organic matter or sand can improve drainage and create an optimal growing environment for sea holly.



One of the primary uses of sea holly is as an ornamental plant in gardens and landscapes. With its spiky, silver-blue foliage and striking flower heads, sea holly adds texture and visual interest to mixed borders, rock gardens, and coastal landscapes. The plant’s unique appearance makes it a valuable addition to flower arrangements and dried floral displays, adding an intriguing and unconventional element to bouquets and centerpieces.

Pollinator Attraction

Sea holly’s nectar-rich flowers attract a variety of pollinators, including bees, butterflies, and other beneficial insects. By incorporating sea holly into a garden or landscape, you can support local pollinator populations and contribute to the overall health of the ecosystem. Additionally, the presence of pollinators can lead to increased biodiversity and a more vibrant and dynamic garden environment.

Dried Floral Arrangements

The distinctive appearance and long-lasting quality of sea holly flowers make them ideal for dried floral arrangements and crafts. Whether used in wreaths, bouquets, or other decorative displays, the spiky and ornate flower heads of sea holly add an intriguing and textural element to dried floral creations. When properly harvested and preserved, sea holly flowers can maintain their color and structure for extended periods, making them a popular choice for both professional florists and hobbyists.


Pruning sea holly is a relatively straightforward process that focuses primarily on maintaining the plant’s shape and removing spent flower heads. Deadheading – the removal of old or faded flowers – encourages the plant to produce new blooms and prolongs the overall flowering period. Additionally, cutting back the foliage in late fall or early spring can help to rejuvenate the plant and promote robust and healthy growth. When pruning sea holly, it is essential to use sharp, clean tools to prevent the transmission of diseases and promote efficient healing of the cuts.


Sea holly can be propagated through several methods, including division, seed sowing, and root cuttings. Each propagation technique offers distinct advantages and challenges, providing gardeners with various options for expanding their sea holly population or introducing the plant to new areas of the garden.


Dividing established sea holly plants is an effective way to propagate the species while simultaneously rejuvenating the parent plant. The process involves carefully digging up the plant and separating the root system into smaller sections, each with a portion of the crown and attached roots. These divisions can then be replanted in suitable locations, where they will establish themselves and grow into new sea holly plants. Division is best carried out in early spring or early fall to coincide with the plant’s natural growth cycles and minimize transplant shock.

Seed Sowing

Growing sea holly from seed is another viable option for propagation, though it requires patience and attention to detail. The process begins by collecting ripe seeds from the plant and sowing them in a suitable seed-starting medium. Due to its hard seed coat, sea holly seeds benefit from scarification – a process that involves breaking or weakening the seed coat to promote germination. This can be achieved by carefully nicking or scraping the seed coat with a sharp blade. Once scarified, the seeds can be sown in containers or directly in the garden, where they will germinate and develop into young sea holly plants. It’s important to note that sea holly seeds may exhibit variable germination rates and may require several weeks or months to sprout, so patience is key when growing sea holly from seed.

Root Cuttings

Root cuttings offer yet another method of sea holly propagation, particularly for gardeners seeking to increase their plant stock or propagate specific cultivars. To propagate sea holly via root cuttings, select healthy, vigorous roots from established plants and carefully cut them into sections, each containing several inches of root. These cuttings can then be planted in a well-draining, sterile medium and maintained under appropriate conditions to encourage the development of new shoots and roots. Root cuttings can be taken in late winter or early spring, providing ample time for the new plants to establish themselves and develop before the onset of harsh weather conditions.

Container Popularity

Sea holly’s adaptability and striking appearance make it an excellent choice for container gardening. Whether grown in individual pots, mixed planters, or hanging baskets, sea holly’s spiky foliage and distinctive flower heads create a visually captivating display. When selecting a container for sea holly, it is essential to choose one with adequate drainage to prevent waterlogged conditions, which can be detrimental to the plant’s health. Additionally, using a well-draining potting mix and providing sufficient sunlight are crucial factors in maintaining healthy sea holly in containers.

Common Diseases

While sea holly is generally resilient and resistant to most diseases, it can occasionally fall victim to certain fungal infections and issues related to poor cultural practices. Understanding the common diseases and ailments that can affect sea holly is essential for maintaining the plant’s health and vitality. Here are some of the prevalent diseases that may impact sea holly:

Botrytis Blight

Botrytis blight, also known as gray mold, is a fungal disease that can affect sea holly and other ornamental plants. It is characterized by the development of grayish-brown, fuzzy growth on the plant’s leaves, stems, and flowers, often accompanied by wilting and decay. Botrytis blight thrives in moist and humid conditions, making proper air circulation and avoiding overhead watering essential for prevention. To manage botrytis blight, affected plant parts should be promptly removed and disposed of, and the surrounding environment should be kept clean and well-maintained.

Root Rot

Root rot is a common issue in plants that are subjected to excessively wet or waterlogged conditions. Sea holly is susceptible to root rot when grown in poorly drained soils or when exposed to excessive irrigation. Symptoms of root rot include yellowing, wilting, and eventual collapse of the plant. To prevent root rot, it is crucial to ensure that sea holly is planted in well-draining soil and that watering is managed appropriately to avoid waterlogged conditions.

Powdery Mildew

Powdery mildew is a fungal disease that manifests as a white, powdery growth on the surfaces of plant leaves, stems, and flower heads. While sea holly is relatively resistant to powdery mildew, certain environmental conditions, such as high humidity and poor air circulation, can create favorable conditions for its development. To prevent powdery mildew, it is essential to maintain proper spacing between plants, promote good air circulation, and avoid overhead watering. If powdery mildew does occur, prompt intervention with appropriate fungicidal treatments can help manage the disease and prevent its spread.

Common Pests

In addition to diseases, sea holly may also attract certain pests that can impact the plant’s health and aesthetic appeal. Identifying and addressing common pests promptly is essential for preserving the vitality and beauty of sea holly. Here are some of the primary pests that may affect sea holly:


Aphids are small, soft-bodied insects that can infest sea holly and other ornamental plants, feeding on the sap and excreting honeydew, which can lead to sooty mold growth. To control aphids, natural predators such as ladybugs and lacewings can be encouraged, and infested plants can be sprayed with a strong jet of water to dislodge the pests. In severe infestations, insecticidal soaps or horticultural oils may be applied to manage aphid populations effectively.

Spider Mites

Spider mites are tiny arachnids that can infest sea holly, causing stippling, discoloration, and webbing on the plant’s foliage. Spider mites thrive in hot, dry conditions and can quickly multiply if left unchecked. To manage spider mite infestations, regular monitoring of plant foliage, promoting humidity, and using targeted applications of insecticidal soaps or miticides can help control and reduce pest populations.


Caterpillars, the larvae of various moth and butterfly species, can occasionally feed on sea holly foliage, leading to visible damage and defoliation. While some caterpillars may not pose a significant threat to the overall health of the plant, heavy infestations can impact the aesthetic appeal of sea holly. Physical removal of caterpillars and the use of biological control agents, such as Bacillus thuringiensis (Bt), can help manage caterpillar populations without the need for broad-spectrum insecticides that may harm beneficial insects.

Botanist’s Tips

Understanding the unique characteristics and requirements of sea holly is integral to successfully cultivating and appreciating this distinctive plant. Here are some expert tips to help you maximize the potential of your sea holly and ensure its long-term health and beauty:

Selecting Companion Plants

When choosing companion plants to grow alongside sea holly, consider species that share similar cultural requirements and complement its distinctive appearance. Plants with silver, blue, or purple foliage can provide an attractive contrast to sea holly’s spiky, silver-blue leaves. Additionally, selecting pollinator-attracting plants can enhance the overall biodiversity and ecological value of the garden, creating a harmonious and dynamic landscape.

Drying Flowers for Crafts

To preserve sea holly flowers for dried floral arrangements and crafts, harvest the blooms when they are in their prime – typically when the bracts surrounding the central cone have fully developed and the flowers are vibrant in color. Hang the harvested flower stems upside down in a warm, dry location with good airflow, allowing the flowers to air dry naturally. Once dried, the flowers can be used in a variety of creative projects, adding a unique and textural element to floral designs and decorations.

Wildlife Garden Design

Incorporating sea holly into wildlife or pollinator gardens can create a thriving ecosystem that supports local biodiversity and contributes to the well-being of pollinating insects. By selecting a diverse range of nectar-rich plants, including sea holly, you can attract and sustain a variety of pollinators, such as bees, butterflies, and other beneficial insects, ultimately promoting a healthy and vibrant garden environment.

Fun Facts

  • The name “Eryngium” is derived from the ancient Greek word for “sea holly,” which reflects the plant’s historical association with coastal regions and sandy habitats.

  • Sea holly is often used in herbal medicine for its purported diuretic and anti-inflammatory properties, as well as its traditional use as an aphrodisiac.

  • The vibrant blue color of sea holly flowers serves as a visual beacon for pollinating insects, attracting them to the plant’s nectar-rich blooms.

  • Sea holly’s spiky foliage and durable nature have inspired its use in traditional folklore and symbolism, where it is often associated with protection and strength.

  • Coastal communities have utilized sea holly as a natural dye source, extracting pigments from the plant for use in textiles and artistic endeavors.

Links to External Resources

For additional information about sea holly and its cultivation, uses, and cultural significance, please refer to the following external resources:

  1. Royal Horticultural Society (RHS) – Eryngium planum ‘White Glitter’
  2. Missouri Botanical Garden – Eryngium planum
  3. University of Wisconsin-Madison Extension – Growing Sea Holly
  4. BBC Gardening – Sea Holly Care Guide

In conclusion, sea holly (Eryngium planum ‘White Glitter’) is a captivating and versatile plant that offers a wealth of ornamental, ecological, and practical benefits to gardeners and plant enthusiasts. By understanding its cultural requirements, propagation methods, and common diseases and pests, you can cultivate and appreciate sea holly to its fullest potential. Whether used in landscaping designs, pollinator gardens, or floral crafts, sea holly’s enduring appeal and distinctive qualities make it a remarkable addition to any garden or landscape.

Remember to embrace the unique attributes and ecological value of sea holly as you engage with this exceptional plant, and explore the rich world of botany and horticulture that it represents.

This blog post was written by an experienced plant scientist with expertise in plant cultivation, ecology, and horticulture. For further inquiries or information about sea holly (Eryngium planum ‘White Glitter’) and other botanical topics, feel free to reach out to the author at [email protected]. Thank you for reading, and may your gardening endeavors be filled with beauty and discovery.

Disclaimer: The information provided in this guide is for educational and informational purposes only. It is not intended as a substitute for professional botanical advice or guidance. Always consult with a qualified horticulturist or plant specialist for specific plant care and cultivation recommendations.

Picture of Peter Taylors

Peter Taylors

Expert botanist who loves plants. His expertise spans taxonomy, plant ecology, and ethnobotany. An advocate for plant conservation, he mentors and educates future botanists, leaving a lasting impact on the field.