How to Grow and Care for Black Hills Spruce Trees
Overview
The Black Hills spruce tree (Picea glauca ‘Densata’) is a cultivar of white spruce known for its dense, narrow form and aromatic blue-green needles. Native to the Black Hills of South Dakota, this tree thrives in cold, dry climates with acidic soil.
Planting and Care
Site Selection
- Choose a location with full sun or partial shade.
- Ensure the site has well-draining soil that is slightly acidic.
- Avoid urban or coastal environments with high humidity or wet conditions.
Planting
- Dig a hole twice as wide as the root ball and just as deep.
- Amend the soil with organic compost.
- Place the tree in the hole and backfill with the amended soil.
- Water deeply after planting.
Watering
- Water weekly during the first two years after planting, especially during periods without rain.
- Once established, Black Hills spruce trees are drought-tolerant and require minimal supplemental watering.
Fertilizing
- No regular fertilization is necessary.
- Apply organic compost to the planting hole when transplanting.
- If nutrient deficiencies are suspected, test the soil and amend as needed.
Pruning
- Prune dead or broken branches anytime.
- Remove drooping lower branches to raise the canopy.
- Optional pruning can be done in late winter or early spring to control size and shape.
Propagation
Cuttings
- Take 6- to 8-inch cuttings from healthy shoots in late summer or early fall.
- Angle the base of the cutting and remove the needles from the lower portion.
- Dip the angled end in rooting hormone and plant directly into moist soil.
Seeds
- Collect seeds from fallen cones in the fall and let them dry thoroughly.
- Place seeds in a plastic bag and refrigerate for three weeks.
- Remove seeds and soak them in water for 24 hours.
- Plant viable seeds in rich soil, cover lightly, and keep moist.
- Germination typically occurs within three weeks.
Pests and Diseases
- Common pests include mites, aphids, and bagworms.
- Treat bagworms by hand removal and apply Bacillus thuringiensis.
- Rust diseases may occur but are rarely a major concern.
Common Problems
- Black Hills spruce trees prefer dry, well-drained conditions.
- Avoid planting in areas with high humidity or wet soil.
- Yellowing and dropping needles may indicate rust disease.
Frequently Asked Questions
Q: Is the Black Hills spruce the same as a black spruce? A: No, these are distinct species. Black Hills spruce prefers drier soil and has blue-green needles, while black spruce prefers wetter soil and has nearly black cones.
Q: How big does a Black Hills spruce grow? A: Black Hills spruce trees typically grow 50 to 70 feet tall and 15 to 25 feet wide.
Q: Are Black Hills spruce trees good trees? A: Yes, Black Hills spruce trees are considered desirable landscape trees due to their compact growth, low maintenance needs, and resistance to pests and diseases.
