In many gardens, containers are used for splashes of bright summer colour. However, as winter approaches, the voids left in the landscape are palpable. Empty containers look off-putting and only emphasise the lack of greenery in the garden. Evergreen shrubs and dwarf conifers, in their countless shapes and colours, can fill empty spaces with year-round interest.
A reputable garden centre will have hundreds of dwarf conifers, in a huge range of shapes, shades and sizes. Slow-growing and compact, trees such as the dwarf white pine, the Alberta spruce and the English yew are often as wide as they are tall. Expanding at an average rate of 30 cm (1 foot) per decade, container-grown specimens rarely reach more than 3 m (10 feet) in height at maturity. Choose miniature varieties if size is an issue. These extremely slow-growing evergreens reach less than 90 cm (3 feet) in height after 20 years.
Conifers alone can make for a dull garden. To avoid creating an unending field of basic green, incorporate a few containerised shrubs with colourful flowers or berries into the design. The compact form of the sweet-smelling daphne is well suited to container culture. Its lemon-scented flowers add colour to the winter landscape, while the shiny green leaves create texture throughout the year. Use low-maintenance hebes to add a classic touch to the garden. Their the gently rounded shapes, attractive spring flowers and variegated foliage add interest without a lot of effort. Alternatively, use the Oregon holly grape to make a more powerful statement. The spiny, holly-like leaves are red when young, taking on purplish overtones in the winter, and the golden spring flowers ripen in the summer into clusters of eye-catching purple-blue berries.
Tropical looking, exotic evergreens, such as the yucca and the leatherleaf mahonia, can create dramatic focal points throughout the landscape. Though the impressive foliage and brightly coloured flowers give these plants a robust appearance, they are hardy enough only for warm areas where frosts are light and cold weather seldom lasts. Placing them in pots makes relocating these heat-lovers for the winter a simple, straightforward task.
The concept of architectural plants may seem like a paradox, for it implies combining the fixed rigidity of a building with the fluid growth of plant life. However, architectural evergreens, such as the common boxwood and the Japanese barberry, combine all the natural grace of a plant with a shape and texture that lends itself to sculpting. Small and compact, the foliage of these slow-growing shrubs can be pruned and shaped into a variety of decorative, distinct forms. Containers filled with these shrubs can be combined with contrasting foliage to create a bold-textured effect.