Busy gardeners appreciate the early spring flowers and minimal care required of evergreen perennials such as epimediums and hellebores. They don’t need dividing or staking or fertilizing, they just do their thing without much gardener intervention. Yet a little attention in late winter will improve the appearance and show off newly emerging flowers.
Roy Farrow, one of the UW Botanic Gardens horticulturists, attends to enormous swaths of epimedium and hellebore in the Washington Park Arboretum’s Witt Winter Garden. When and why does he trim the leaves off? “We attempt to cut down all our Epimedium [foliage] by flowering time – which translates to late winter to make sure we don’t miss the window. The reason we don’t do it any earlier is either they are good evergreen ground covers or they have particularly colorful foliage in the winter.” Sometimes due to less than ideal cultural conditions, epimedium foliage can look bedraggled by November. The leaves can be cut off then, but that carries risk as well. Roy observes: “[people] love to trample all over areas that have plants about to come up.”
Helleborus x hybridus (H. orientalis) foliage gets cut back earlier in the year at the Arboretum, but some established patches that are particularly hardy rarely receive attention. The main reason to remove foliage is to focus attention on the new flowers emerging from the center of the plant. However, Roy reports, “In some gardens they get botrytis quite badly and look terrible by the end of fall and it’s a good idea to cut down the foliage to keep the inoculum down. Sometimes it’s aphids that drive people to cut down foliage and then flowers later on.” The Winter Jewels series plants have been especially susceptible to disease.
Hellebore species, such as H. argutifolius and H. foetidus flower on stems that grew the previous year and then decline later in the year. This type of hellebore should be left alone in winter.