Habit: Eryngium x zabelii 'Neptune's Gold' grows to be an clump forming perennial with flower stems above the foliage. Eryngium zabelii 'Neptune's Gold' is a versatile perennial that produces large spiky steely-blue flowers that rise above the spiny foliage in summer. About this cultivar: ; Habit · Clump forming, bushy ; Foliage: Deciduous ; Height: 60 - 90 cm (2 - 3 ft) ; Spread: 45 - 75 cm ( - ft) ; Time to full growth: 2. The plants have an upright and sturdy growth habit, reaching up to 2' tall with a ". The spiny bracts can sport varying gradients of chartreuse and blue. The bracts show colors from gold to silver to lavender to blue. A new and totally unique introduction of Sea Holly - the foliage of this Eryngium is a brilliant golden colour, it will become lime green if slightly shady. A stunning. Golden leaves contrast nicely with steel blue stems and deep periwinkle blue flowers. Height: up to 40 - 60 cm (2 ft); Spread. Imagine this in an eryngium, "the spiky bracts are silvery blue at the base, turning gold at the tips. . The stems of 'Neptune's Gold' are blue, and the foliage.