University of Illinois Extension

Summer Flowering Shrubs

In spring, it seems that every shrub in town is in flower.

Sharon Yiesla

"Then summer comes and it seems that it's hard to find a flowering shrub anywhere," said Yiesla. "There are actually quite a few summer-flowering shrubs, but they are often overlooked , simply due to the time that the consumer is shopping. Most gardeners go shopping in spring, when they see spring-flowering shrubs in abundance. The summer bloomers get overlooked, because they are not showy in spring."

The hydrangeas are a good choice for summer flowering shrubs. Panicled Hydrangea (Hydrangea paniculata) is an old-fashioned favorite with many new varieties available. It is a medium to large shrub growing 10-15 feet tall. The large clusters of white flowers turn pinkish in late summer and then brown as the clusters persists on the shrub. Full sun to partial shade is best for this shrub.

Hydrangea quercifolia

Hydrangea quercifolia

Smooth Hydrangea (Hydrangea arborescens) is another favorite. The variety 'Annabelle' is very popular for its large round clusters of white flowers in summer. This shrub grows three to five feet tall and does best in partial to full shade. Oakleaf Hydrangea (Hydrangea quercifolia) also has large clusters of white flowers in summer. The leaves look like oak leaves and provide some red or russet fall color. This shrub grows three to six feet tall and can grow in sun or shade. A slightly protected site is best in northern gardens.

Cephalanthus occidentalis

Cephalanthus occidentalis

"For bright yellow flowers, look to the St. Johnsworts. Kalm St. Johnswort (Hypericum kalmianum) has bright yellow flowers in midsummer and blue green foliage all season," she said. "It grows only two to three feet tall and does best in full sun.

"Shrubby St. Johnswort (Hypericum prolificum) also has bright yellow flowers in midsummer. It is slightly larger (three to four feet) and can grow in full sun or partial shade."

Other mid-suumer bloomers include:

Shrubs that flower in the latter part of summer include:

Caryopteris

Caryopteris

Hibiscus syriacus

Hibiscus syriacus