Santolina chamaecyparissus

Often referred to as Cotton Lavender, Santolina forms dense rounded bushes of slightly spiky, upright grey foliage, topped in summer by little buttons of yellow flower.  A versatile and useful plant which can be grown in most soils, as long as they are well drained, it is fully hardy and evergreen.  Can grow to 60cm x 80cm, but less if clipped immediately after flowering.  Prefers a sunny spot.