Dwarf Alberta spruces (Picea glauca "Conica") mature to a 10- to 12-foot height and 3- to 5-foot basal circumference. The tough, elegant conifers handle temperatures approaching minus 50 degrees Fahrenheit. Their narrow, conical form and dense, fine light-green needles make the trees ideal candidates for spiral pruning. Spiral-cut Conica trees provide a striking entryway or formal garden accents. Their liabilities include an intolerance of urban pollutants, saline or extremely wet soils and hot, humid climates.
Plant Conica in moist, well-drained, acidic soil and in areas with full sun to partial shade. If your winters bring icy roads, place the tree out of range of splashing road salt.
Position the tree a few feet from nearby plants and structures. Its dense, moisture-connecting foliage needs air and sunlight to promote quick drying.
Plant between spring and early fall so the tree’s roots establish before entering winter dormancy. Use the shovel to dig a hole a foot deep and at least a foot wider than the tree's root ball.
Remove Conica from its container. Untangle the root ball and use stem clippers to trim back roots encircling it.
Center the tree with the top of its root ball level with the hole's lip. Replace enough soil to cover the root ball. Tamp firmly to remove air pockets. Shape the remaining soil into a mound, encircling the tree a few inches from its base.
Direct a stream of water from the garden hose into the basin between the soil mound and tree. Water thoroughly.
Water frequently during the first year. In dry periods, water weekly. A late-fall soaking decreases risk of winter-burned foliage.
Maintain a 2- to 4-inch layer of organic mulch around your Alberta spruce. Leave a clear area between the mulch and trunk to prevent moisture buildup. Mulch options include peat moss, straw, shredded bark or pine needles.
Feed with a late-spring or fall mulch of manure or application of high-nitrogen fertilizer. Spread fertilizer according to label specifications and dig it into the soil's surface. Keep dry fertilizer away from the spruce or its roots. Water the fertilizer into the soil.
Prune Conica's broken or dead branches with the saw. Maintain the spiral cut's corkscrew shape with the pruning shears. Clip back two-thirds of the new growth in midsummer, when the tree is partially dormant, recommends the University of Wisconsin Extension.
Remove invading summer insects from your spruce with a strong blast from the garden hose. Saturate the entire tree.
Check for mite infestations through the growing season. Tap each branch while holding a piece of white paper beneath it. Mites appear as red specks on the paper. Treat infested spruces with a miticide applied according to the manufacturer's instructions.