Pot Size: 1 gal
Accepted Scientific Name:
Picea pungens 'Fat Mac'
Origin and Habitat
Picea pungens, commonly known as Colorado blue spruce, is native to the central and southern Rocky Mountains of the United States, where it thrives in high-altitude forests with cool summers, cold winters, and well-drained, gravelly soils. 'Fat Mac' is a cultivated dwarf selection originating from a witches’ broom mutation. It maintains the species’ notable cold-hardiness and silvery-blue needle color but in a compact, globular form suited for smaller garden spaces. It has gained popularity in rock gardens, urban landscapes, and container plantings due to its tidy habit and dense branching.
Description
Picea pungens 'Fat Mac' is a slow-growing, dwarf evergreen conifer that typically reaches 18 to 24 inches in height and width. It forms a tight, rounded mound with stout branches and striking silvery-blue needles. The needles are rigid, sharp to the touch, and radiate uniformly around the stems, giving the plant a full, plush appearance. While cone production is rare in this miniature form, its dense shape and vibrant blue foliage offer year-round ornamental interest. 'Fat Mac' brings bold color and structure to compact spaces.
Cultivation
Zone USDA Zones 3–7
Temperature Tolerates temperatures from -35°C to 30°C; performs best in cool to temperate climates.
Growth Rate Very slow-growing; adds 1–2 inches of growth per year.
Soil Prefers well-drained, slightly acidic soil amended with pumice for aeration and root health.
Watering Water deeply and allow the top layer of soil to dry before rewatering. Avoid standing water.
Fertilizing Feed every 2–3 weeks with a balanced, slow-release or liquid fertilizer formulated for conifers.
Light Thrives in full sun. In warmer regions, provide light afternoon shade to prevent needle burn.
Pests and Diseases Generally low-maintenance and pest-resistant. Monitor for spider mites or aphids in dry or stressed conditions.
Propagation
Best propagated by grafting onto standard Picea pungens rootstock to maintain dwarf characteristics.
