Flowering shrubs are an alternative to labour-intensive annuals and perennials. Not all flowering shrubs are scented, but fragrance, which attracts pollinators, is present in many of the most common, such as lilacs, roses and butterfly bushes. Even container gardeners can find compact versions of traditional, scented favourites. With a little planning, a gardener can ensure flowers throughout the growing season.
Early Spring Shrubs
One of the earliest shrubs flowering in spring is witch hazel (Hamamelis), an upright shrub with small, spider-like, scented flowers. Common varieties, like Arnold promise, have bright-yellow blooms. Varieties with orange flowers are also available. Another early spring bloomer is the Buffalo or Missouri currant (Ribes odoratum), which has clove-scented, yellow flowers. Later, the shrubs also produce glossy black edible fruits. Both witch hazel and Buffalo currant thrive in part shade and moist ground. Pieris or Andromeda features evergreen foliage and tiny, cream or pink, bell-shaped flowers that smell like honey.
Beginning in late spring, roses bring fragrance to the garden. Choose roses with strong fragrance, like the rugosas and their hybrids. Some hybrid musk roses, especially Felicia, have a strong old-rose fragrance. Many of David Austin's English roses are also strongly scented and are compact enough for container growing. Old-fashioned sweetbriar roses (Rosa eglanteria) have lovely flowers, but the best fragrance comes from the foliage, which is apple-scented. Sweet briars include Lord Penzance and Lady Penzance.
Late Spring Shrubs
Lilacs are among the best-known, scented, spring bloomers with panicles of hundreds of small, tubular flowers. The shrubs bloom in shades of cream, yellow, blue, blue-purple and purple. All varieties are intensely fragrant. Many viburnums have sweetly scented spring flowers, usually borne in rounded heads or clusters. Scented varieties include Viburnum carlesii and the low-growing Viburnum davidii. Viburnum has attractive leaves and red, blue or black berries in the fall.
Summer Flowering Shrubs
In warmer zones, pittosporum fills the air with the sweet scent of its five-petaled, white flowers. Calycanthus floridus has aromatic leaves and pineapple-scented flowers. The flowers, which appear late in summer, are distinctive, with narrow, swirling, reddish-brown petals. Clethra alnifolia, is available in pink or white-flowered varieties. It is a compact shrub with bottle brush-shaped flowers and somewhat hairy leaves. Butterfly bush, or Buddleia is sometimes known as "summer lilac", with lilac-like flower panicles in shades of yellow, pink, purple and blue-purple.
Some spring and summer bloomers, like reblooming roses and butterfly bush continue blooming through the fall months. Another shrub, Caryopteris x clandonensis, sometimes called "blue mist shrub," produces fluffy-looking blue or blue-purple blooms in late summer or early fall. The flowers are somewhat fragrant, but the foliage is intensely aromatic.