Most side yards have limited space, so choosing plants can be challenging. Often side yards fall within the shadow zone of multi-story buildings, necessitating shade-tolerant boxwoods (Buxus spp.), upright yews (Taxus spp.), euonymus, hostas, hakone grass (Hakonechloa spp.), and ground-hugging wild gingers (Asarum spp.).
Where rainwater washes down walls, ferns, hostas, sedges (Carex spp.) and moss might suffice. If light is not a limiting factor, a fuller range of sun-loving shrubs, perennials, annuals and ornamental grasses are possibilities. Tight spaces are ideal locations for container gardens that can be used to frame benches, steps and border paths.
If the space allows for columnar and vase-shaped trees and shrubs, some of my favorites are Blue Arrow juniper (Juniperus virginiana 'Blue Arrrow'), Pencil Point juniper (Juniperus communis 'Pencil Point'), upright Japanese yew (Taxus cuspidata) and the compact bloodtwig dogwood (Cornus sanguinea 'Compressa'). Larger spaces might accommodate the beautiful semi-double, pink-flowered Amanogawa columnar Japanese cherry (Prunus serrulata ‘Amanogawa’), Lucas pyramidal hornbeam (Carpinus betulus 'Lucus') and the showy pink-flowering Chinese redbud (Cercis chinensis).
Small side gardens can be quite colorful when you include plant choices such as this flowering quince.