Sundrop. Oenothera 'Shimmer' is a low mounding perennial with slender silver leaves and 3 inch wide lemon yellow flowers. Drought tolerant for us, but it performs better with some supplemental water during the summer. Winter deciduous, the spring leaves emerge green in spring before maturing a distinctive silvery-gray. 'Shimmer' makes a good choice for container, borders, or could also be used in a ground cover tapestry. Hardy to 10F.