Yellow Flowering Shrub that Blooms in Summer

St. John's Wort

• St. John's wort is the name for a variety of deciduous shrub species from Europe and Asia, adapted to North America. Hypericum beannii grows to 3 feet, handles the climates of USDA zones 6 and 7, and serves as ground cover or a low hedge, blooming from July into September. Yellow flowers and foliage are the highlight of Hypericum calycinum "Brigadoone." This St. John's wort form grows to 12 inches, has yellow July and August flowers, and works well in rock gardens because of its small size. Hidcote is a compact hybrid form growing to 4 feet high and blossoming during the entire summer.

Shrubby Cinquefoil

• Shrubby cinquefoil (Potentilla fruticosa) is a northern hemisphere native and as such has some cold tolerance, growing from USDA zones 2 through 7. The flowers resemble buttercups and bloom on 2- to 4-foot-tall bushes from June until frost kills them. Absaraka and Fargo are about 3 feet high and have larger flowers than the parent species does. Gold Drop and Goldfinger bloom for long periods during the summer. Use Hallman Dwarf along foundations; it grows to 2 feet high and excels in cool summer weather in northern locations.

Miniature Roses

• The foliage and the flowers of miniature roses are smaller than those of normal varieties are, but the yellow versions are just as vivid as their counterparts. A large shrub capable of climbing trellises, Rosa Savaclend is a cultivar that blooms from May through first frost, with yellow flowers touched with a reddish tint on their edges. It develops to 12 feet in full sunshine. Savagood and Golden Halo are much smaller, both in the 12-inch to 24-inch range. Savanade is a thornless shrub, with yellow flowers from May well into the autumn. These summer bloomers survive between USDA zones 5 and 9.

Evergreen Shrubs

• The evergreen shrubs capable of providing a landscape with yellow summer flowers are not particularly cold hardy, but Kalm's St. John's wort (Hypericum kalmianum) does tolerate USDA zone 4 cold. It grows to 3 feet, blooms in July and August, and has some drought tolerance. In USDA zones 5, 6 and 7, Jerusalem sage (Phlomis fruticosa) dies all the way down to the ground in winter before coming back in spring. In zones 8 through 10, the shrub remains evergreen. The yellow flowers develop between June and August. Yellow flowers resembling buttons, as well as aromatic, silvery-gray leaves, highlight lavender cotton (Santolina chamaecyparissus) -- a Mediterranean shrub for USDA zones 6 through 9.