Fully doubled, round, glistening white flowers appear above the green finely dissected foliage as temperatures start to warm in late spring to early summer. Not reliably winter hardy in Chicago gardens, this cool season annual is usually sold as a potted plant early in spring for planting outdoors. As temperatures warm, the plants bolt (send up their flower stalks) topped by a succession of flowers. Adapted to desert regions, this plant will go into dormancy as soon as hot weather arrives. Gardeners may also purchase dormant bulbs that should be planted as soon as the soil is warm enough to work in early spring. Deer and rabbits find all plant parts unpalatable.