A wealth of shrubs grow successfully across Oklahoma, which enjoys USDA hardiness zones 6 and 7. Both native and exotic plants, deciduous or evergreen, comprise the list of possible hedge or screening plants. Match the plant with the soil and hardiness rating for your part of the state, realizing that the further west you go, the more wind and cold, and more alkaline soils the plants must tolerate. In eastern counties, rainfall is more plentiful and the soils more neutral to acidic in pH.
Formal Clipped Hedges
Choose shrubs with smaller foliage for formal, oft-clipped hedges and screens. Large-leaf plants' leaves tear and look jagged and unkempt after mechanical pruning and shearing. Glossy abelia (Abelia grandiflora), wintergreen barberry (Berberis julianae), boxwood (Buxus spp.), yaupon holly (Ilex vomitoria) and other evergreen hollies, yew (Taxus spp.) and devilwood (Osmanthus heterophyllus) make exceptional hedges for neat, formal appearances.
Planting shrubs in a line and not judiciuosly pruning each year allows them to form an informal, natural look. These plant species form dense hedges with slightly jagged forms, but overall quite satisfactory for hedges or windbreaks. Cherrylaurel (Prunus caroliniana), cotoneaster (Cotoneaster spp.), firethorn (Pyracantha spp.), forsythia (Forsythia cultivars), deciduous and evergreen hollies (Ilex spp.), juniper (Juniperus spp.), photinia (Photinia spp.) and viburnum (Viburnum spp.) make excellent hedges and offer spring flowering, fruits or fall foliage interest as well. While barberry (Berberis thunbergii) and honeysuckle (Lonicera spp.) may be inexpensive choices, be wary of them as they are aggressive or even invasive, sprouting seedlings elsewhere and becoming a nuisance. Disease-resistant roses (Rosa spp.) may also make a handsome informal hedge.
For added beauty or visual weight year-round, avoid deciduous shrubs and focus on evergreen shrubs--those with either broad leaves or needles or scales. Arborvitae (Thuja spp.), yews and junipers make handsome needled hedgerows with effective wind-blocking qualities. Broad-leaf shrubs include azaleas and rhododendrons (Rhododendron spp.), wax myrtle (Myrica cerifera), cherrylaurel, photinia, devilwood, evergreen holly, evergreen viburnum and privet (Ligustrum spp.) offer a different texture. Realize that some species need an acidic soil to prosper, especially rhododendrons and azaleas, and some may prove invasive thanks to bird-dropped seeds, such as privets.