The Blue Sea Holly
For easy care, plant your sea holly in full sun and a well drained soil. It will reward you with amazing blue flowers in summer months and interesting foliage. Lets take a closer look.
The Blue Sea Holly, scientifically known as Eryngium, is an eye-catching perennial plant celebrated for its unique spiky blue flowers and striking architectural form.
A number of species have the blue flowers including Eryngium planum, Eryngium bourgatii and Eryngium alpinum. All have similar requirements.
Known for its silvery-blue foliage and sharp, thistle-like appearance, the plant is ideal for adding a bold, dramatic element to gardens, particularly in coastal and Mediterranean-inspired landscapes.
The Blue Sea Holly thrives in well-drained soil and full sun, often attracting pollinators such as bees and butterflies. This plant is not only ornamental but also quite hardy, making it a favorite among gardeners in a variety of climates.
A wonderful foliage plant with brilliant flowers are Eryngium species with deep green foliage and wonderful blue flowers. However a few different forms exist such as the well known Eryngium Giganteum ‘Miss Willmott’s Ghost’. Long flowering throughout summer with silver cones and white flower petals.
Commonly called ‘Sea Holly’ this is one of the great plant for seaside plantings, it copes with poor sandy soils, extended dry periods and even the salt air.
How to Plant Blue Sea Holly (Eryngium)
- Position:
Choose a location that receives full sun, preferably a spot that mimics the plant’s natural coastal habitat. Blue Sea Holly does best in open areas where the soil is well-draining and not overly rich. - Planting:
Dig a hole twice the size of the root ball. Place the plant into the hole so that the top of the root ball is level with the soil surface. Backfill with soil and gently firm it around the roots. - Spacing:
Space plants 12 to 18 inches apart to allow for their wide, spiky growth. - Pruning Blue Sea Holly:
Prune Blue Sea Holly in late winter or early spring before new growth begins. Deadheading spent flowers will also encourage a cleaner appearance and may prolong blooming. - Cutting Back:
After the plant has finished flowering, cut back the stems to the base to promote healthy regrowth. In winter, remove any dead foliage to tidy up the garden.
Give it a light pruning after flowering, (deadheading) and thats about all of the care that it needs.
Eryngium Varieties
With over 250 species plants do differ in growth habit, flower colour and folaige form, these are some of the more popular varieties.:
- E. amethistinum.
- E. campestre.
- E. giganteum: Miss Willmott’s ghost – Pale white to green flowers with a silvery collar.
- E. planum.
- Eryngium alpinum – Blue Glow Sea Holly or Alpine Sea Holly
- Eryngium ovinum – Blue Devil An Australian Native species found in NSW, Victoria, SA and WA.
- E. pandanifolium.
- E. x tripartitum, variifolium.
- E. x zabelii “Violetta”
- Eryngium yuccifolium. Yucca Leaved Sea Holly. Cream to white flowers Reaches 1m in height.
- Eryngium decaisianum (syn Eryngium pandanifolium) or Giant sea holly this has red flowers
When Buying Blue Sea Holly
- Look for Healthy Plants: When purchasing Blue Sea Holly, look for plants with firm, healthy leaves and a strong root system. Avoid plants with yellowing foliage or signs of pests.
- Container vs. Bare Root: Blue Sea Holly is commonly available in both containers and as bare-root plants. Container-grown plants establish faster, while bare-root plants may be cheaper and offer a wider selection of varieties.
- Choosing Varieties:
Choose a variety that suits your climate zone and garden design. Eryngium giganteum is a striking choice for a more dramatic display, while Eryngium planum offers a more compact form.
Remember, different species have different flower colours and foliage
Eryngium plants are available for sale from the following nurseries
52 Rodd St Canowindra NSW 2804
An online nursery specialising in drought and frost tolerant perennials and fragrant, edible and herbs.
www.perennialle.com.au
357 Monbulk Road SILVAN VIC 3795
Guaranteed "garden worthy" bulbs, plants and perennials. Visit the website to browse our large range of daffodils or request the latest free catalogue.
www.tesselaar.net.au
'Umbango' 750 Humula Rd, Humula NSW 2652
Phone 0408692773 Great Range of Perennial plants available for sale by mail order.
www.nutshellnursery.com.au
Little Hampton, Vic 345
"Mail order nursery specialising in cottage garden perennials, flowering shrubs, Trilliums, Hostas and Pacific Coast Iris. Flat rate express postage - Except WA & TAS"
www.botanicaltreasures.com
125 Palmer Rd Jindivick 3818
Open Thursday - Sunday 10am - 4pm
Specialising in growing and selling Rare and Unusual Trees, shrubs Perennials Bulbs and Climbers, a unique nursery with amazing stock.
www.muskersbroughtonhall.com.au


