Dwarf Alberta spruce. Can these trees be planted in a large, cut-off barrel as I don’t have the room for them to be put in the ground? We live in southeast Saskatchewan. They are about two feet in height now. How tall will they grow? Thank you.
Dwarf Alberta Spruce (Picea glauca var. Albertiana ‘Conica’) are prized for their natural cone shape, bright green needles and slow growth habit. At maturity, they will reach about 3.5 m (10 ft) high an about 1 m (3 ft) wide. Because of the latter, they do grow well in containers, as long as you provide well drained, acidic soil. Soil should be changed and or amended every two years, to provide support and nutrients to the trees.
Alberta Spruce, particularly in a pot, should be sheltered from wind, watered regularly, and out of hot sun. Before winter sets in, the trees should be watered until freeze up to keep them from dehydrating. They then should be moved to a sheltered location, such as a shed or unheated garage, or wrapped for winter to protect them from winter burn. In cold areas, it might be wise to insulate the interior of the pot with styrofoam insulation board before putting in the soil.
Depending on where you are in southeastern Saskatchewan, your plant hardiness zone ranges from 3b to 4b, although zone 3b is the most prevalent. See the following to confirm where you are:
Alberta Spruce, despite its name, is hardy from zone 4 to 9. Alberta spruce would be borderline hardy in your location. So, you could put Alberta Spruce in your half barrels, but they would need to be sheltered for the winter, possibly in a shed or unheated garage.
If you want to know more about Alberta Spruce: https://web.extension.illinois.edu/dmp/palette/080629.html