I have several butterfly bushes. Are they to be cut back in the winter or the spring? What about hibiscus – should they be cut back?
Butterfly bush and other “woody perennials” such as St. John’s wort (Hypericum) and blue mist spirea (Caryopteris) often require pruning in early spring. In severe winters, the tops are often killed back. Remove any stems that are not leafing out by mid-April. The established root system will quickly return the plant to its normal size. There are several types of hibiscus. The perennial hibiscus noted for its large, dinner plate-size flowers should be cut back in early spring to 4 to 6 inches. The shrub hibiscus, also known as althea or rose of Sharon, does not need to be cut back. It is one of the last shrubs to leaf out, often not doing so until late May.