Deep in the Rocky Mountains more than 100 years ago, the blue spruce tree was discovered.
Fast forward to today, this evergreen beauty has become a classic tree around Christmastime and even an ideal plant for adding privacy to your yard. That means you’ve probably seen a blue spruce before, and you might even have a hunch that there’s one in your yard. But how can you know for sure?
Look no further! Below, find out how to identify a blue spruce tree.
Tree Identification by Leaf
True to its name, blue spruce tree needles are blue-green in color. Some trees have a subtle white cast that makes the needles look silvery-blue. The wax layer on the outside of the needles is the cause for the whitish-silvery hue. The tree’s needles are also stiff and very sharp to the touch.
Tree Identification by Flower
Blue spruces don’t have showy flowers, but they are adorned with light brown cones that grow in the top half of the tree.
Tree Identification by Bark
Blue spruce tree bark can be pale gray or light brown with a scaly texture.
How to Care for Blue Spruce Trees
- Grow zones: Blue spruces can be planted in zones 2-7. They do well in cold climates, but they can’t handle excessively hot or humid weather.
- Where to plant: A blue spruce isn’t overly fussy about soil. It can grow in nearly any soil type as long as it has good drainage.
- How tall do blue spruce trees get: These trees grow anywhere from 30-60 feet tall and about 10-20 feet wide.
- Sunlight: Plant your blue spruce in an area that it will get full sun, which is at least 6 hours of direct sunlight per day.
- When do blue spruce trees bud: Since blue spruces keep their needles year-round, there’s no set bud time. However, they do grow new needles in the summertime.
- How to prune a blue spruce: Typically these trees don’t need to be pruned unless there’s a pest or disease issue. If you do prune to fix a problem, or just to give your tree a shape up, do it during the winter season.
- Do deer eat blue spruce: Nope! Blue spruces are generally deer resistant.
Potential Threats
Keep an eye out for symptoms of a blue spruce tree in trouble.
- Yellowing needles in summer that turn brown and drop in fall. This is likely Rhizosphaera needle cast, a fungal disease that targets blue spruce trees after a stretch of wet or humid weather conditions. Learn how to treat needle cast here.
- Brown needles and white sap oozing from tree bark. Cytospora canker causes this. It’s a fungal disease that primarily attacks older and unhealthy blue spruce trees. Read more about Cytospora canker.
- Yellow or brown needles and sticky honeydew. These are signs of an aphid infestation. Aphids feed on trees by sucking the sap and excreting honeydew, sometimes causing needles to drop. Here’s how to use dormant oil to treat aphids.
Still not sure what type of tree you have? Contact your local arborists! We are more than happy to help.
