This information is provided as a free service to viewers. We do not sell these plants.
Overview
Eryngium x planum 'Sapphire Blue' is a sterile Sea Holly cultivar that produces spectacular blooms that start out greenish but darken to a luminescent blue
This deciduous, herbaceous perennial has stiff, spiky foliage and very divided in form.
This plant will flower over extended periods of summer and they also make superb cut flowers, especially when dried.
They go well in mixed borders when planted in groups of at least six plants, and most informal garden styles, though also contribute strikingly to smaller courtyard gardens and gravel gardens.
Soil: They like moderately fertile, well drained soils in a sunny location - the more sun, the bluer the flowers,
Full sun is best for optimum results.
They do well in dry and sandy soils and do not like extended periods of wet feet, especially in the dormant period over winter.
Maintenance: Generally this is a low maintenance plant.
Most flowers are cut back after life has escaped them, but Eryngium make a good display of the dry flowerheads over winter.
Cut back firmly however as the season turns towards spring.
They do not transplant well so choose your location carefully.
Do not fertilise as all the nutrients go into the stems and do not improve the flowers.
Diseases: Leaf and bud eelworms have been noted as occasional problems, as have powdery mildew and root rot.
Other Species: There are 250 species in the Eryngium genus of biennials and perennials.
They share the same family as the carrot !
Eryngium x planum 'Sapphire Blue' was bred by Wouter Ruigrok of Hillegom, Holland.
Author: Bob Saunders.