Astrantia Superstar (syn 'White Giant') - The large, greenish-white flowerheads look like pincushions surrounded by a spidery ruff of green-tinted, white bracts. These are produced en masse above the lobed, dark green leaves from early summer to autumn adding bobbles of colour to the border. Astrantias have become the 'darlings of the designers' in recent years as they lend themselves to most styles of planting, and mix happily with most plants.
Try this science experiment with children over the course of several days. Fill up 4 vases with different coloured water and put 1 white carnation in each one. Watch the flowers over the next four days change to the colour of the water.