Plant climbing vines at the base of the courtyard walls. English ivy (Hedera helix) is a natural choice because it climbs any vertical surface. The ivy will provide greenery year-round and add vertical interest to the courtyard. Flowering vines such as clematis or trumpet vine (Campsis radicans) will add spring and summer color. Attach a trellis against a wall for these plants to climb.
Include neatly clipped and shaped hedges in the courtyard for an authentic English garden look. Boxwoods, or Buxus, are ideal, as they are easy to grow, evergreen, come in many heights and take well to pruning. Another good choice is yew, or Taxus, which is also a dense evergreen that is easy to shape. If your courtyard doesn't have walls, create them by growing a tall boxwood or yew hedge.
Select ornamental trees to provide shade and soften the walls of the courtyard. Spring-flowering trees such as the dogwood (Cornus florida) or the eastern redbud (Cercis canadensis) will add color and additional vertical interest to the courtyard. Choose ornamentals that are relatively low-growing and won't outgrow the courtyard.
Plant shade-loving perennials such as hostas and ferns beneath the ornamental trees. They will provide a backdrop of green and white during the spring, summer and fall.
Add annuals, planted in the soil or in containers, for bright color all summer. For a traditional English look, plant them in urns around a topiary or a dwarf Alberta spruce.