Genus of about 35 species of conifers, native to the north hemisphere. It contains countless varieties that thrive only in areas where there is high air humidity and low temperatures.
Latin name: Picea glauca "Alberta"
Evergreen trees (from which many dwarf cultivars have been developed) with green or glaucus foliage, consisting of small needles with rhombic cross-sections, arranged in spirals around the branches which grow on the bulges of the branch. The cones are pendent and they don't break apart when they drop to the ground.
They grow in neutral or acid, deep, moist soils and in partly shaded sites with high air humidity.
Tall plants are planted alone and in clusters, and the dwarf varieties are cultivated in rock gardens, plant arrangements and in flowerpots. They are used as Christmas trees but with the drawback that the needle retention is poor.
They are prone to aphids, causing them to loose their needles. Also subject to red tetranychus.
The typical species are propagated by seeds that germinate easily and the cultivars by grafting or by cuttings that take two years to root.
Small shrub with a very dense, broadly conical crown and green foliage.