Late September. I love the layers and contrast in texture along this border: the tall Perovskia ‘Blue Spire’ is still flowering blue as we have still had no frost, but it will frazzle to bare white twigs as the autumn gets colder; Yucca gloriosa adds a grey-green spiky structure that will remain all year round; semi-evergreen, penstemons throw up the occasional late, pink flower; and the stinky curry plant, Helichrysum italicum will keep it’s icey foliage through the winter.
