A miniaturized version of a spruce tree with a slow growth rate is referred to as a "dwarf spruce." These coniferous evergreen trees belong to the Picea genus, just as standard sized spruce trees do. There is no single type of dwarf spruce, and most varieties are simply smaller versions of standard sized spruces. The most popular dwarf spruce is the dwarf Alberta spruce, also called the dwarf white spruce, but the dwarf blue spruce is another common variety.
Picea glauca "Conica" is the most common dwarf Alberta spruce and is also the most popular dwarf spruce used in gardens and landscapes. A standard sized Alberta spruce reaches a height of 49 to 98 feet (approximately 15 to 30 meters), while the dwarf version can reach a height of roughly 8 feet (approximately 2.5 meters) after a 25 year maturation period. Due to their size and conical shape, mature dwarf Alberta spruce trees are often used as Christmas trees. They have short, dense needles that start out with a light green hue and become gray-green as the branches get older. Other types of dwarf Alberta spruce trees do exist, but the "Conica" is the most frequently used.
Conical dwarf Alberta spruce trees thrive in cool, moist climates, but they can also grow in warm, hot climates. The trees can be watered once a week in temperate weather, but may need more frequent watering in dry, hot conditions. Like all evergreens, the dwarf Alberta grows year-round, but landscapers may need to wrap young trees in burlap during the harsh winter months since strong, freezing winds can dry the tree out and cause long-term damage. These trees also require well-drained soil and partial to full sun in order to survive. The plants can be pruned into various shapes, but a gardener or landscaper needs to do very little pruning if he or she wants the tree to keep its natural conical appearance.
Another popular type of dwarf spruce is the dwarf blue spruce. The Picea pungens "Globosa," also called the globe blue spruce, is the most common type of dwarf blue spruce even though other varieties also exist. Standard sized blue spruce trees grow to a height between 82 and 89 feet (approximately 25 to 30 meters), but this particular dwarf only reaches heights between 3 and 5 feet (approximately 1 to 1.5 meters) within a 10 year span of time. This evergreen makes a popular shrub in gardens and landscapes. It has a globular shape and a relatively flat top. The branches have a distinct blue-green hue and are densely packed together.
Globe blue spruce trees thrive best when planted in full sun and in well-drained or dry soil. This dwarf spruce can readily adapt to other conditions, but a dedicated gardener or landscaper should avoid planting the shrub in full shade or in consistently soaked, packed soil. The tree needs a weekly watering but does not need to be drenched. Consistent pruning is required to help maintain the shape and size of the plant.