The needles on a dwarf Alberta spruce may turn brown for a number of reasons such as spider mite infestation, cytospora canker fungal disease, rhizosphaera and stigmina. Environmental stress due to air pollution, poor soil, winter salt spray, heat or high light reflection can stress a plant and cause brown needles. Lack of proper air circulation and water, especially during periods of drought, may also cause needles to dry. The shrub is resilient and typically recovers with proper care.
A dwarf Alberta spruce does best in a full or partial sun location. Soil should be well-draining and topped with a layer of organic mulch. The best region to grow these trees is in U.S. Department of Agriculture plant hardiness zones two to eight.
One of the most common causes of brown needles on a dwarf Alberta spruce are spider mites, sap-sucking insects approximately one-sixtieth of an inch long. To check for spider mites, hold a sheet of white paper underneath an affected branch and shake it. Examine the paper for any small, dark specks that move. To remove the mites, spray the shrub with a forceful stream of water. Insecticides containing bifenthrin, dicofol, and fentabutatin-oxide are also effective against mites, as are more natural treatments such as canola, clove, cottonseed, petroleum or sesame oils.