Needle evergreen shrubs, like pine or spruce, offer a level of sophistication to the landscape when planted in containers. Why plant an evergreen shrub in a container instead of planting in the ground? Typically, the answer is because planting is not an option. Buried pipes or utility lines may prohibit planting shrubs. Potted shrubs are also an option on an architectural hard surface like at a front entry, or as a part of the landscape design around a pool or large patio or desk.
Difference between a tree and a shrub
Is the needle evergreen you like a tree or a shrub? It makes a difference because a tree may need more space for root expansion than achievable when confined to a container. The National Park Service tells us that, “Generally, trees are over 20 feet tall and have trunks more than 2 inches in diameter at 4.5 feet above the ground. Shrubs are smaller than trees and often have many small, woody, bark covered stems rising from the base.”
Choosing needle evergreens for containers
In landscape design, the conical shape of needle evergreen shrubs adds height while the dome-shaped needle evergreen can add dimension and width. Select dwarf varieties of needle evergreen, many of which do not exceed 5 to 7 feet in height, to keep the evergreen shrubs in containers indefinitely. Taller shrubs may eventually require re-potting to a larger container or planting in the ground. If the shrub becomes too large for the container, consider donating the shrub to a charity, like a church, for planting.
Dwarf needle evergreen shrubs
Dwarf varieties of spruce include Alberta (Picea glauca ‘Albertiana Conica’), Alberta White (Picea glauca ‘Conica’), Globe Blue Spruce (Picea pungens ‘Glauca Globosa’), and Norway (Picea abies ‘Clanbrassiliana’). Dwarf varieties of pine include Eastern White (Pinus strobus ‘Nana’) and Mugho (Pinus mugo ‘Sherwood Compact’). Dwarf varieties of cypress include Hinoki False Cypress (Chamaecyparis obtusa ‘Nana Gracilis’).
Placement in the landscape
Set potted evergreens sporadically around a pool near seating areas, or line up the container shrubs to create a privacy screen. On a patio or deck, place the shrubs in a corner or just to the side of bottom step. Evergreens in containers look elegant on a front porch or stoop. Imagine the fun of adding colored lights on the shrubs for holidays!
Caring for needle evergreen shrubs in containers
Water is critical to any potted plant, but more so in hot climates. The container may require daily watering. To slow dry-out, apply 2 to 4 inches of organic mulch around the base of the shrub. Pine chips and leaf mold are organic mulch options. In addition, look for a container with insulated sides that will block both heat from the sun and cold winter winds.
More from this contributor:
Container Garden Secrets to a Beautiful Landscape
Transplanting a Root Bound Potted Tree or Shrub
Tips on Choosing Outdoor Flower Pots or Containers
Sources: ‘Trees and Shrubs,” National Park Service; “Selecting Landscape Plants: Needled Evergreens” and “Choosing Landscape Evergreens,” University of Missouri Extension