Iberis 'Snowsurfer' (Candytuft). Dark green uniform mounds of shiny leaves are frosted with drifts of snow white flowers in spring. They are evergreen in warmer climates, but in most areas of Zone 3-4, winter cold will damage the leaves. Mulching is necessary, if snow is lacking. Dead branches need to be cut off for growth to begin again. Pruning back after spring flowering is recommended.