Habit: Eryngium x zabelii 'Neptune's Gold' grows to be an clump forming perennial with flower stems above the foliage. A stunning. Height: up to 40 - 60 cm (2 ft); Spread. Eryngium zabelii 'Neptune's Gold' is a versatile perennial that produces large spiky steely-blue flowers that rise above the spiny foliage in summer. Imagine this in an eryngium, "the spiky bracts are silvery blue at the base, turning gold at the tips. The bracts show colors from gold to silver to lavender to blue. The spiny bracts can sport varying gradients of chartreuse and blue. 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 stems of 'Neptune's Gold' are blue, and the foliage. . The plants have an upright and sturdy growth habit, reaching up to 2' tall with a ". Golden leaves contrast nicely with steel blue stems and deep periwinkle blue flowers. 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.