Shrubs are an important component of habitat or wildlife gardens, providing many benefits including cover for birds, insects and animals; nesting places; and food sources. In rural settings, shrubs can be used as hedgerows or in transition areas between gardens and woodlands. In urban and suburban gardens, they can be intermingled with a variety of trees, perennials and annuals to provide an oasis for wildlife. Some gardeners use only native shrubs, while others include appropriate non-natives in habitat plantings.
Fruiting shrubs are essential to a habitat garden and should be chosen for a mix of summer, fall and winter fruiting species. Blueberry, raspberry and huckleberry bushes bear fruit in early summer. Fall fruiting species include yew, red osier dogwood, inkberry and winterberry holly, and juniper. Shrubs that retain fruits over the winter include viburnum, sumac, pyracantha, various rose species and northern bayberry. In addition to providing food for wildlife, fruiting shrubs contribute visual interest, especially in winter.
Flowering Shrubs -- An Important Food Source
Nectar-rich flowering shrubs are important to butterflies, bees and hummingbirds. In addition to serving as a food source, the berry bushes mentioned above provide flowers, usually in the spring. Among the best flowering plants for habitat gardens are azaleas, andromeda (Pieris) and rhododendrons, especially native species; pepperbush (Clethra); and sweetspire (Itea). Butterfly bush, which is not native to the United States, is also an excellent nectar source but can become invasive in some areas.
Shrubs with dense growth habitats make the best cover for birds, insects and small animals. In selecting shrubs for this purpose, it is important to cluster the plants and layer them -- incorporating plants of varying heights and densities. Evergreens like yews, rhododendrons and some hollies are important since they provide year-round cover and shelter, especially for non-migratory birds. Branches pruned from shrubs can also be gathered and used as brush piles to provide shelter for chipmunks, rabbits, toads and other small wildlife.
When selecting shrubs for habitat areas, consider the site and the soil. Some shrubs, like rhododendrons are natural understory plants and can withstand dappled shade from deciduous trees. Others, like rose species, prefer full sun. Soil chemistry is important. Laurels, azaleas and other species only flourish in acidic soil. Another consideration is soil moisture. Bayberries, for example, are good habitat plants but prefer relatively moist soil conditions. Ceanothus americanus or New Jersey tea, on the other hand, flourishes in normal to dry conditions.
Large and Small Habitats
Shrub habitats do not have to be large. Schoolyard habitats have become popular as both ecological and educational tools. These plots can incorporate smaller shrubs species in addition to other plants. Bushes can also do double habitat duty, serving as natural supports for species like trumpet vine (Campsis), which attracts hummingbirds.