Colorado spruce tree plants are evergreen trees and grouped with the conifers. They are members of the pine family. The species plant is native to the Rocky Mountain states in the United States. One of the cultivars to grow is 'Glauca,' which is a Latin word that indicates a grayish-blue color. It is the official tree of the state of Colorado.
- Botanical Name: Picea pungens
- Common Name: Blue Spruce, Green Spruce, White Spruce, Colorado Spruce, Colorado Blue Spruce
- Plant Type: Spruce tree
- Mature Size: In the wild, it can grow up to 75 feet. In parks and gardens, it typically grows 30 to 60 feet high and 15 to 20 feet wide.
- Sun Exposure: Full sun to partial sun
- Soil Type: Moist, well-drained soil
- Soil pH: 6.0 to 7.5
- Bloom Time: Year round growth, no flowers
- Flower Color: No flowers; silvery-blue needles
- Hardiness Zones: Colorado blue spruce trees can be grown in USDA plant hardiness zones 3 to 7
- Native Areas: From northern New Mexico through Colorado and Utah to Wyoming and into Alberta and British Columbia
How to Grow a Colorado Blue Spruce Tree
The Colorado Blue Spruce's silvery-blue needles are prickly to the touch and have a strong, fresh, piney smell. Its pyramidal shape, foliage color, and wonderful smell make this plant a classic choice for a Christmas tree.
These plants can be planted in rows to form windbreaks or "living-wall" privacy screens. But they are equally effective when simply used ornamentally, as specimen trees. Not only are they popular as Christmas trees, but their boughs are also useful in various kinds of Christmas decorations using greenery. From wreaths to swags to holiday garlands, lovers of tasteful Christmas yard decorations turn to boughs from evergreens such as Picea pungens for raw material for crafts projects. Some people even lay the cut boughs over a shrub shelter to provide "roofing" that will help the protected bush make it through the winter in good shape.
Colorado blue spruce trees are valuable in deer country, as their prickly texture and strong smell render them conveniently deer-resistant. In the snowy North, where landscapes can look barren in winter, evergreens such as Colorado blue spruce trees can provide much needed winter interest.
These trees do best in a location with a moist, well-drained soil made fertile through the use of soil amendments. This specimen is tolerant enough of mildly acidic soil to be grouped with the acid-loving plants, but it is not overly fussy about soil pH and will perform just as well (maybe even a bit better) in ground that has a neutral pH. They grow wild in forests at higher elevations, so often have to grow in rocky soil. Make sure the soil is well draining. A poorly draining soil can result in root rot and poor growth.
This tree is very drought tolerant and can survive in periods of low water. It does thrive with moderate water levels. Avoid water logging the tree or creating areas with standing water. Water sparingly and let the tree soak up the water before adding more.
Temperature and Humidity
The Colorado blue spruce is tolerant of cold weather. It can tolerate heat to a point. The plant will not thrive in extremely hot and humid weather conditions.
These trees do not need frequent fertilization. You can fertilize them in the spring, before the growing season. This will give the tree an added nutrition boost. It will likely increase the length of the needs and improve the needle color. You'll want to sprinkle 10-10-10 slow-release granulated fertilizer over the soil in the root zone. Then water with about two inches of water to prevent fertilizer burn and incorporate the fertilizer into the water.
Potting and Repotting
A growing trend is to buy them live (in containers) for indoor Christmas decorating, then plant them outside as landscape plants after the holiday. Dig the hole in the ground for planting well before December, so you will not have to dig through frozen dirt. Bring the excavated dirt inside, to keep it from freezing. This will help to keep it loose so that you will have workable dirt with which to fill in around the new specimen after transplanting it into its hole.
Varieties of Colorado Blue Spruce Trees
- Dwarf Varieties: These are pruned to desired shapes and sizes
- Gloria: A low growing variety with a mature height of 12 inches
- "Moerheim" blue spruce: Grow to a medium height, with a maximum around 30 feet tall
- "Iseli Foxtail" or "Foxtail" blue spruce: These varieties have an unusual pattern of needle growth on its branches
Colorado blue spruce trees do not need to be pruned, but they can be pruned if you wish to promote denser foliage. Prune off half of the fresh growth on each candle (that is, the tip at which branch growth occurs each year) in spring. Make sure to water young plants during dry spells. Apply 2 or 3 inches of garden mulch around the plants (but not up against the trunks) to help retain moisture in the soil.