Container gardening offers a viable options for those who love to cultivate plants but don't have a lot of space. Containers are functional -- gardeners can move them inside during severe weather, they offer a measure of control over plant size and allow for easy garden redesign. Evergreen shrubs keep their foliage through the winter and offer screening, privacy and year-round texture and colour. When choosing the best shrubs for your outdoor garden, select small, slow-growing species and appropriately sized containers.
The Colorado State University Extension website includes lavender (Lavandula angustifolia) among its recommendations of the best evergreen container shrubs. This evergreen grows slowly to 2 feet tall with a 3-foot spread. It has aromatic, grey-green foliage and produces bright purple, white, pink and blue flowers in summer. Lavender grows best in full sun and well-drained to dry soil. It is hardy in USDA zones 5 to 8. The Extension also recommends dwarf Alberta spruce for containers. This slow-growing evergreen reaches heights from 3 to 10 feet with a 2- to 3-foot spread. It prefers full sun and moist, well-draining soil and is hardy in zones 5b to 7. This compact shrub has dense, soft, aromatic green needles and requires wind protection.
Auburn University's website suggests planting evergreen shrubs with flowering plants such as pansies for an extra splash of colour. The university's list of recommended shrubs for containers includes boxwoods (Buxus spp.). These versatile evergreens grow in a variety of sizes, colours and shapes. The variegated boxwood (B. sempervirens "Aureovariegata") has yellow and green foliage and grows from 8 to 10 feet tall with an equal spread. It is hardy in USDA zones 6 to 8. The Harland boxwood (B. harlandii) grows from 4 to 6 feet tall with a similar spread. It has dense, glossy green leaves on low-growing branches and is hardy in zones 7b to 9. Both boxwoods prefer sun to partial shade and moist, well-drained soil.
The University of Delaware's Cooperative Extension website includes junipers and dwarf holly shrubs among its recommendation of the best shrubs for containers. The Compressa juniper (Juniperus communis "Compressa") grows very slowly to 3 feet tall with a 6-inch spread. This narrow evergreen has silver-blue and green needles and ascending, dense branches that create a neat, formal appearance. It is hardy in USDA zones 2 to 9 and prefers full sun and well-drained soil. Holly selections include the dwarf horned holly (Ilex cornuta "Rotunda"), a 4-foot-tall evergreen with a similar spread. This holly has glossy, spiny foliage and produces white spring flowers followed by red berries. It prefers sun to partial shade and moist, well-drained soil and is hardy in zones 6 to 9.
North Carolina State University's website describes the Goshiki holly tea olive (Osmanthus heterophyllus "Goshiki") as being "on more 'most beautiful' lists than any other shrub." This evergreen's new foliage emerges in shades of pink and purple, then ages to green, yellow and white. Its lustrous foliage resembles that of a holly plant. Goshikis grow to 8 feet tall and wide and tolerate severe pruning. They grow best in partial shade and rich, well-drained, moist soil, but will grow more slowly in full sun. Goshikis are hardy in zones 6 to 9. North Carolina State University chose the Shrubby or Chinese podocarpus (Podocarpus macrophyllus "Maki") as a plant of the month, noting its ability to thrive in containers. This slow-growing evergreen can reaches heights of 35 feet but usually grows much shorter. It has a stiff, formal shape and is hardy in zones 7 to 11. The shrubby podocarpus thrives in sun to shade and requires well-drained soil.
- Colorado State University Extension: Container Gardening
- Colorado State University Extension: Container Gardens; M. Roll, et al.; May 2006
- Auburn University; The Joys of Container Gardening; Ken Tilt, et al.
- University of Delaware Cooperative Extension; Container Gardening; Jay Windsor; September 1997
- North Carolina State University; Using Plants to Attract Wildlife; Shawn Banks
- North Carolina State University; Shrubs; Erv Evans