So named because it has the scent and flavour of olives, as a culinary herb the leaves give a delicious olive-like flavouring to savoury dishes. Olive Herb, or Santolina rosemarinifolia ‘olivia’, is a hardy perennial that’s very low maintenance. It’s a small compact shrub up to 50cm high equally happy in borders and containers. Come summer time it produces small yellow button flowers.