Planting Blue Spruce
Blue spruce is an evergreen that, though officially grows below the alpine tree-line, typically grows at higher altitudes near streams in mountain valleys where moisture levels in the soil have a greater ratio to the area’s rainfall averages. It’s a native in the central and southern Rocky Mountain regions and largely planted as an ornamental tree.
Growing Blue Spruce
Blue spruce can be propagated by bare root, container, cuttings, and from the seed. These trees produce seeds every 20 years and have a moderate ability to spread through seed production; seedlings have low vigor, however. In the early stages of growth, these trees benefit greatly from moisture and shading, which prolong snow and soil moisture in late spring. Many people like to buy them in containers for indoor Christmas decorating and then plant outside as landscape plants. Though, the hole should be dug and soil saved for planting well before December to avoid frozen dirt. Here are some general guidelines for planting:
- Planting is generally suggested for the fall.
- Plant in a location with full to partial sun. If you are planting saplings, experts suggest using 2 foot tall ones.
- Soil should be moist, fertile, and well-drained with a pH level between 5.5 and 7.8. Add compost or fertilizer to the bottom of each hole where you'll be planting a blue spruce if your soil is of extremely low quality.
- Dig a hole that is three times the width and a few inches deeper than the network of roots, also known as the root ball.
- When planting, be sure to position the plant so that it is centered and the top of its root ball is level with the surrounding ground.
- Fill the hole back up with soil and level the top out. Water lightly and place a couple inches of mulch around its base to encourage moisture.
- Stake the plant if necessary using the pieces of an old garden hose to protect branches from the support wires. Remove stakes as soon as the tree becomes established.
- Water every day until the tree becomes established.
Tips & General Care for Blue Spruce
- Blue spruce cannot survive exposure to temperatures below -38 degrees Fahrenheit.
- These trees have a medium tolerance to drought and restricted water conditions.
- Pruning isn’t necessary, unless you want to promote denser foliage. When pruning, cut half of the fresh growth on each growing tip, or candle, in the early spring.
- Water young trees once a week in dry weather.
- Fertilize in the spring and the fall in the third year of a tree’s life.
- The most common enemy of these trees is a fungus called Rhizosphaera needle cast. It starts at the bottom of the tree and makes needles turn brown and fall off. As for insects, the white pine weevil and western and eastern budworms are ones to look out for.
- As it is a hardy plant overall, you may want to position blue spruce trees to block wind and sun from overwhelming other delicate plants on your property.
