Blue Glitter Sea Holly (Eryngium planum ‘Blue Glitter’) is a stunning and unique perennial plant that can add an extraordinary pop of color and texture to any garden. Its spiny, thistle-like appearance and striking blue color make it a favorite among garden enthusiasts looking for something a little different. As a hardy plant that can thrive in a variety of conditions, it’s also an excellent choice for gardeners who want low-maintenance but visually striking plants.
What Is Blue Glitter Sea Holly?
Blue Glitter Sea Holly, also known by its botanical name Eryngium planum, is a perennial plant native to Europe and Asia. It belongs to the Apiaceae family, which also includes parsley, celery, and carrots. However, Blue Glitter Sea Holly stands out for its ornamental appeal rather than its culinary uses.
The plant is recognized for its intensely blue flowers, which resemble small, spiky balls surrounded by stiff, bristly, bluish-green foliage. The plant has a somewhat alien look, making it a fantastic choice for gardeners who want to add a little drama to their landscapes. The flower stems are long, thin, and upright, typically reaching 2 to 3 feet in height. Blue Glitter Sea Holly blooms from mid-summer to early fall, making it a great addition to gardens for late-season interest.
Key Features of Blue Glitter Sea Holly:
- Height: 24 to 36 inches
- Spread: 12 to 18 inches
- Bloom Time: Mid-summer to early fall
- Sun Requirements: Full sun
- Water Requirements: Low to moderate
- Soil Type: Well-draining, dry to medium moisture soils
- USDA Hardiness Zones: 4-9
The plant’s long-lasting blooms and striking appearance also make it a favorite for cut flower arrangements and dried flowers.
Growing Conditions for Blue Glitter Sea Holly
Blue Glitter Sea Holly is a hardy plant that can adapt to various conditions, but for best results, it’s essential to provide the right growing environment. Here’s what you need to know about its ideal conditions:
Sunlight Requirements
Blue Glitter Sea Holly thrives in full sun. It requires at least six hours of direct sunlight per day to produce its characteristic vibrant blue flowers. The more sunlight it receives, the better its color and growth will be. While it can tolerate light shade, the plant will not develop as intense a color in those conditions, and it may become leggy and weak.
Soil Requirements
One of the key reasons Blue Glitter Sea Holly is so popular is its ability to grow in poor soil conditions. It prefers well-draining soil and can thrive in sandy or rocky soils, which makes it ideal for rock gardens or areas with less fertile soil. In fact, overly fertile soils can result in weaker stems and less impressive flowers. The plant is drought-tolerant once established, so it does not need rich, moisture-retentive soil.
- Optimal Soil: Sandy, loamy, or rocky soil
- Soil pH: Neutral to slightly alkaline
- Drainage: Excellent drainage is essential to prevent root rot
Watering Needs
Blue Glitter Sea Holly is quite drought-tolerant, making it a low-maintenance option for gardeners in dry climates. While it does need regular watering during its first growing season to establish a strong root system, mature plants can tolerate extended periods of dry weather. Overwatering or allowing the soil to become waterlogged can lead to root rot and other issues.
- Watering Frequency: Once established, water occasionally during prolonged dry spells.
- Avoid: Overwatering, waterlogged soil, and poor drainage.
Temperature and Hardiness
This plant is hardy in USDA zones 4 through 9, which means it can survive winter temperatures as low as -30°F (-34°C). It tolerates both heat and cold reasonably well, making it an excellent choice for a wide range of climates. In hotter areas, the plant will appreciate some afternoon shade to prevent scorching, although it generally prefers full sun.
- USDA Hardiness Zones: 4-9
- Frost Tolerance: Highly frost-tolerant and can survive freezing winters.
Planting and Care for Blue Glitter Sea Holly
Planting Blue Glitter Sea Holly is relatively straightforward, and the plant doesn’t require a lot of special care once it’s established. Here’s a step-by-step guide to planting and caring for this unique perennial.
When to Plant
The best time to plant Blue Glitter Sea Holly is in the spring or early fall. Planting in the spring allows the plant to establish itself during the growing season, while fall planting gives it time to settle in before the onset of winter dormancy.
How to Plant
- Choose the Right Location: Select a spot that receives full sun and has well-draining soil.
- Prepare the Soil: If necessary, amend the soil with sand or grit to improve drainage, especially in areas with heavy clay soil.
- Planting Depth: Dig a hole about twice the width of the root ball and just as deep. Place the plant in the hole and fill it in with soil, ensuring that the crown of the plant is level with the surrounding soil.
- Spacing: Space plants about 12 to 18 inches apart to allow for airflow and prevent fungal diseases.
- Watering: Water thoroughly after planting to help the plant settle in. Be careful not to overwater.
Mulching and Fertilization
Blue Glitter Sea Holly doesn’t require much fertilization. In fact, over-fertilizing can lead to lanky growth and fewer flowers. A light application of a balanced, slow-release fertilizer in the spring can encourage blooming, but it’s not strictly necessary.
As for mulching, a thin layer of gravel or coarse mulch can help retain moisture and suppress weeds. However, avoid heavy, moisture-retaining mulches like wood chips, as these can encourage rot in this drought-tolerant plant.
Pruning and Deadheading
Pruning and deadheading are essential for keeping your Blue Glitter Sea Holly looking its best throughout the growing season.
- Deadheading: Removing spent flowers can encourage more blooms and prevent the plant from self-seeding excessively. Simply snip off the dead flowers at the base.
- Pruning: In late fall or early winter, you can cut back the plant to ground level once the flowers have faded and the foliage begins to die back. This helps prevent disease and keeps the plant looking tidy.
Pests and Diseases
Blue Glitter Sea Holly is generally resistant to pests and diseases, thanks to its tough, spiny foliage. However, some common garden pests like aphids or spider mites may occasionally be attracted to the plant. These can typically be controlled with insecticidal soap or by rinsing the plant with water.
The most significant disease concern for Blue Glitter Sea Holly is root rot, which can occur if the plant is overwatered or planted in poorly draining soil. Proper soil preparation and careful watering practices can prevent this issue.
Using Blue Glitter Sea Holly in Your Garden
Blue Glitter Sea Holly’s unique appearance makes it an excellent choice for various garden settings. Whether you’re aiming for a formal garden, a cottage garden, or a rock garden, this versatile plant can be a great addition. Here are a few ideas for incorporating it into your garden design.
Pollinator-Friendly Gardens
One of the main benefits of planting Blue Glitter Sea Holly is its appeal to pollinators. Bees, butterflies, and other beneficial insects are attracted to its long-lasting, nectar-rich flowers. By planting this sea holly, you can encourage biodiversity in your garden and support local pollinator populations.
Cottage and Informal Gardens
Despite its spiky appearance, Blue Glitter Sea Holly fits beautifully into cottage gardens, where it can provide contrast to softer, more delicate flowers like roses, lavender, and daisies. Its upright form and unusual texture add interest without overwhelming the garden’s informal, relaxed aesthetic.
Drought-Tolerant Gardens
If you live in a region with hot, dry summers or you’re looking to reduce water usage in your garden, Blue Glitter Sea Holly is an ideal choice. Its drought tolerance makes it perfect for xeriscaping or planting in areas that receive minimal irrigation.
Cut Flower and Dried Flower Arrangements
Blue Glitter Sea Holly’s long-lasting flowers make it an excellent option for cutting gardens. The striking blue blooms are perfect for fresh flower arrangements, and they retain their color and structure when dried, making them popular for dried flower crafts and bouquets.
Rock Gardens and Coastal Gardens
Because it thrives in poor, well-drained soils, Blue Glitter Sea Holly is an excellent addition to rock gardens or coastal gardens. Its spiny, thistle-like form looks natural among rocks and gravel, and it tolerates the harsh conditions that many other plants cannot.
Blue Glitter Sea Holly vs. Similar Plants
While Blue Glitter Sea Holly has many unique characteristics, it’s always a good idea to compare it to other similar plants to see if it’s the right choice for your garden. Below is a comparison table that highlights the differences and similarities between Blue Glitter Sea Holly and other popular spiky, drought-tolerant perennials.
| Feature | Blue Glitter Sea Holly | Russian Sage | Globe Thistle | Lavender |
|---|---|---|---|---|
| Botanical Name | Eryngium planum | Perovskia atriplicifolia | Echinops ritro | Lavandula angustifolia |
| Height | 24-36 inches | 36-48 inches | 24-36 inches | 12-24 inches |
| Bloom Time | Mid-summer to early fall | Mid-summer to fall | Summer | Summer |
| Sun Requirements | Full sun | Full sun | Full sun | Full sun |
| Water Needs | Low | Low | Low | Low to moderate |
| Soil Type | Well-drained, sandy or rocky | Well-drained, poor soil | Well-drained, sandy soil | Well-drained, slightly alkaline |
| Flower Color | Vibrant blue | Lavender-blue | Steel blue | Purple |
| Pollinator Friendly | Yes | Yes | Yes | Yes |
| Drought Tolerance | High | High | High | Moderate to high |
| Deer Resistance | Yes | Yes | Yes | Yes |
| Cut Flower/Dried Flower | Yes | Yes | Yes | Yes |
As you can see, Blue Glitter Sea Holly stands out for its spiky, intense blue flowers and its ability to tolerate drought and poor soils. However, if you’re looking for a taller plant or something with a more sprawling habit, Russian Sage or Globe Thistle might be a better fit. Conversely, for a more compact plant with a soothing fragrance, lavender is an excellent choice.
Conclusion
Blue Glitter Sea Holly is a fascinating and visually striking plant that brings texture, color, and uniqueness to any garden. Whether you’re planting it as a centerpiece in a pollinator-friendly garden, using it in cut flower arrangements, or adding it to a rock garden for drought-tolerance, this plant offers versatility and low-maintenance beauty. With its hardy nature, Blue Glitter Sea Holly is a fantastic choice for gardeners of all experience levels, providing endless aesthetic appeal with minimal effort.
By understanding its growing conditions and care requirements, you can ensure that your Blue Glitter Sea Holly thrives and becomes a standout feature in your garden for years to come.