New Zealand Flax Yellow Wave Originating in New Zealand, phormiums do very well in milder, coastal parts of Ireland, and will even naturalise. Phormium Yellow Wave is an evergreen perennial which forms a huge clump of long arching leaves. The long, sword-shaped leaves, up to a metre long, are green with a broad yellow stripe, like a splash of sunlight in the garden. This is a plant to grow for its magnificent architectural quality; the spikes of red flowers are rarely produced in Ireland, but may surprise you in hot summers. New Zealand flax Yellow Wave does well in seaside conditions, but needs winter protection in colder parts of the country. Site: Tolerates exposureSoil: Light, well drained soilPosition: Full sun preferredSeason of interest: All yearHardiness: Frost hardyHeight: 8’ (2.5m) Spread: 5’ (1.5m)