Thalictrum or also known as chinese meadow rue - are fantastic perennials that when in full flower they seem to hover over the heads of everything else. They are great at creating that nice airy feel especially if your border is packed with full flower heads. Thalictrum Delavayi Hewitts Double bear masses of long lasting pom pom, double pink-lavender flowers from their glaucous blue-green leaves in late Spring, height can reach up to 100cm. To plant meadow rue they do really well in light shade and reasonable shade, to grow thalictrums they don't like to be over crowded and to make sure there is always room for them it might be worth in spring time, dividing the clump, that way you get more plants and it keeps them happy as well. With the plants getting quite tall it is more suited to the middle or back of the border, it doesn't need any support as it will rely on the other plants.