Dwarf flowering shrubs are a lovely addition to the landscape. Two of my favorites are potentilla and Japanese spirea. Though both are deciduous and have little winter interest, they also both have interesting foliage and flowers throughout the summer and fall and both of them survived the harsh winter of 2013-14.
Potentilla, also called shrubby cinquefoil, is native to the Northern Hemisphere. It is a small shrub usually one to four feet tall with upright branches with white, yellow, or, on a few cultivars, pink flowers. The leaves are of particular interest and are the reason for name cinquefoil which means five leaved. The leaves, about one inch long, are digitate which means the leaflets group around acommon center like fingers and thumb around the palm of the hand. Though the name cinquefoil means five, some varieties have three leaflets and some seven.
The showy flowers have five petals around a little yellow center, are 1 to 1 1/2 inches in diameter and bloom from June until the first frost. The flowers grow scattered up the branch though there may be several at the tip. The upright branches can be used in flower arrangements both for greenery and flowers.
As noted earlier, potentilla are easy to grow and do well in extremely cold temperatures. They grow best in full sun and enjoy well-drained moist soil, but they can adapt to poor soil and are tolerant of some drought.
Potentilla provide ground cover for small birds and can be used for feed for livestock. For landscape use, they can be pruned back in the winter. This helps keep a dense round habit to the shrub.
Japanese spirea is also easily grown in full sun in medium well-drained soil. It is an upright rounded shrub which forms a compact mound about 30 inches tall. One cultivar, “Little Princess” has pink flowers in flat-topped clusters in early summer. The faded flowers can be deadheaded to promote more flower growth. The leaves are oval and sharply toothed mint green. These flowers can also be used in flower arrangements like the potentilla.
There are several cultivars of Japanese spirea that have been developed for different flower and foliage color. “Gold Mound” has golden yellow foliage most of the season with an autumn color of orange red. “Mertyann” (Dakota Goldcharm- this name is trademark protected) begins with new leaves of light bronze which change to a bright yellow gold as they mature. “Neon Flash, a red flowered cultivar, has new leaves where emerge reddish and change to dark green. “Shibori” has white, pink, and deep pink flowers on the same plant. All grow to 3 to 5 feet tall with a mound width of 4 to 5 feet.
Japanese spirea, as the name implies, are native of Japan and China. They are hardy in zone 4 to 8 and enjoy the cooler northern summers. They should be pruned in late winter or early spring.
Both potentilla and Japanese spirea are recommended for foundation plantings. Neither of these shrubs have significant pest or disease problems and both are easy to prune. Both make a colorful graceful addition to the landscape.