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. 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. 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 ". . 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. A stunning. The spiny bracts can sport varying gradients of chartreuse and blue. Imagine this in an eryngium, "the spiky bracts are silvery blue at the base, turning gold at the tips. Habit: Eryngium x zabelii 'Neptune's Gold' grows to be an clump forming perennial with flower stems above the foliage. Golden leaves contrast nicely with steel blue stems and deep periwinkle blue flowers. The bracts show colors from gold to silver to lavender to blue.