Picea pungens, commonly called Colorado spruce (also blue spruce), is a medium to large, narrow, pyramidal conifer with horizontal branching to the ground. It typically grows 30-60’ tall in cultivation, but may reach 100’ or more where it grows naturally. It is native to the central Rocky Mountains from southern Montana and eastern Idaho south to New Mexico where it is typically found growing in moist locations from 6000 to 11000 feet in elevation. Stiff, bristly, four-angled, green to blue-green to silver-blue needles (to 1.5” long) point outward from the branches in all directions. Cylindrical light brown cones (to 4” long) have flexible scales. Dark gray bark furrows on mature trees. From a horticultural standpoint, trees with blue or silver blue foliage are generally more coveted than trees with green foliage.
Easily grown in average, acidic, medium moisture, well-drained soils in full sun. Tolerates some light shade. Prefers rich, moist soils. Although established plants have some drought tolerance, soils should be kept consistently moist and not allowed to dry out in the early years. Hardiness zones 2-7
The seeds have a period of dormancy. They can be planted outdoors in the fall or winter for spring germination or they can be cold stratified to simulate winter conditions and to break their dormancy at any time of the year.
- Soak the seeds in water for 24 hours.
- Put the mixture in a ziplock bag.
- Put the bag in the refrigerator and leave it there for 4 weeks.
- The seeds like rich, moist soil. Sow the seeds in containers with a good quality potting soil or compost.
- Cover the seeds with a thin layer of soil about a couple of millimeters thick.
- Water the soil so that it is moist but not wet. The seeds will begin to germinate in 10-14 days.
- When the seedlings are a few inches tall, they can be transplanted.