Dwarf Alberta spruce, also known by its botanical name Picea glauca "Conica," is a small, evergreen dwarf cultivar of the Alberta white spruce, native to the northwestern region of North America. It grows very gradually, reaching maturity over a period of many years, and is widely available at home and garden centers
Alberta spruce is a relatively slow growing species of tree, attaining a mature height of 12 feet after about 50 years. The tree grows vertically at a rate of 3 inches per year, and much more slowly horizontally. Dwarf Alberta spruce trees spread about 5 feet laterally, over a period of many years. Estimate mature sizes for landscape use by multiplying 3 inches by the number of years the tree is expected to reside in the landscape.
Dwarf Alberta spruce trees grow best in full sun, though they tolerate partial shade. The dense foliage requires airflow and sunshine to avoid excess moisture retention, which means dwarf spruce trees should be planted away from structures or dense stands of tall trees. They prefer moist, well-draining soil with a high proportion of organic matter. Dwarf spruce trees are intolerant of drought, dry soil, air pollution and excessive heat, which makes them poor choices for urban plantings.
The slow growth habit of dwarf Alberta spruce makes it an excellent choice for planting in confined spaces, since many years will pass before the tree outgrows its container. It thrives as a container plant, and requires little pruning. The tree makes an excellent specimen or focal point in landscaped areas, and is also frequently used as an entryway or foundation shrub. Their pyramidal, symmetrical shape makes them popular in formal garden plantings, and they can be difficult to integrate into less manicured settings.
There are relatively few problems associated with growing dwarf Alberta spruce, but the tree is susceptible to a small number of insect pests and infections, and sometimes reverts to its species form. Dwarf cultivars sometimes take on the growth habits of larger white spruce trees and disable the genetic switch responsible for dwarfism, although the exact reason for this is unclear. The dense foliage of dwarf Alberta spruce trees is an ideal habitat for red spider mites, which can quickly damage a healthy tree, although they are easily controlled with miticide sprays. Root rots are also a common problem in dwarf spruce culture, but avoiding excess irrigation greatly reduces their incidence.