There are many varieties, including double-flowering impatiens that have more petals but smaller florets, he says. Rose campion (Lychnis coronaria) is a perennial that is easy to grow. "This is ...

But, it's a good idea to combine bottle greens such as yew, box, and osmanthus with gray-leaved plants such as Stachys byzantina and Lychnis coronaria 'Alba' to avoid the planting feeling gloomy,' ...