Spruce trees can range anywhere from tiny, dwarf plants to towering trees. They can live in Zones 2, 3, 4, 5, 6, and 7. They love partial to full sun, fertilizer, and plenty of water. The soil for Spruce trees should be acidic, well-draining, and consistently moist.
Spruce trees are wonderful as windbreaks, privacy fences, and specimen trees.
Planting Spruce Trees
Spruce trees are best planted while they are still dormant, usually in early spring. Make sure that the tree is planted before it shows signs of new growth. It is recommended that you plant your Spruce trees right before the last frost of the season, before it begins thawing. Avoid planting Spruces during the hotter months in the summer, as these conditions will be too dry.
If your Spruce tree is an older tree, not a sapling or youngling, you can plant the tree during the late summer/early fall. The University of Nebraska says the soil should be anywhere from 60-70°F. These trees can be planted after the first hard frost.
Watering Spruce Trees
Spruce trees should be watered if there is less than 1 inch of rainfall per week. Adequate root formation requires you to water Spruce trees down deep at a slow rate. Placing the hose at the base of the Spruce and setting the water flow on trickle will allow the water to seep in deep into the soil. Once the soil is wet at least 2 inches into the ground, you can stop watering.
Supplemental (weekly) watering should be stopped after mid-August so that the trees can prepare for dormancy. One final watering should be given in the late fall. When spring comes around again, you can trickle water the Spruce trees until the water reaches 2 feet underground.
Mulching Spruce Trees
Spruce trees should have approximately 4 inches of mulch around the base of the tree, approximately 5 inches away from the trunk. It should reach out to the edge of the tree canopy so that it will help keep the soil moisturized and help to keep the weeds down.
Fertilizing Spruce Trees
Spruce trees should be fertilized after the final frost in the spring. For each foot your Spruce is tall, fertilize with 1/3 lb. of fertilizer. The fertilizer should extend out about 2 feet away from the trunk of the tree. The fertilizer should not touch the trunk of the tree and the fertilizer should be mixed into the soil with a hank rake. Water afterwards for maximum absorption.
Pruning Spruce Trees
Before new Spruce growth begins in the spring is the best time to prune. Stems and side branches should be pruned halfway, with the outer limbs pruned mainly for shaping. The leader (very top of the tree) can be pruned by 2-3 inches to reduce height.
Diseases
One of the most common diseases is the Cytospora Canker. This is a fungal disease that causes cosmetic damage in the form of gum oozing from the infected spot and usually can be spotted lengthwise across branches (appearing ovular/elongated). Needles will turn brown during spring and summer when Cytospora Canker. The bark will also become orange, brown, or black where the fungus is centralized. If left untreated, the tree will die within a few years.
The most popular Spruces that Cytospora Canker like are the Colorado Blue Spruce, Black Spruce, and White Spruce. It can be transported through water, wind, and contaminated equipment. To ensure that your Spruce tree is not susceptible to the Cytospora Canker, make sure that your trees are not weakened, stressed, or injured. Spruce trees that are well-maintained are less likely to need special treatment. Make sure that your Spruce trees are planted and growing in full sun, as fungi like dark, damp, colder temperatures.
Treatment of Cytospora Canker includes ensuring that there are no open wounds on the Spruce to where the fungus can enter or grow, removing and burning diseased parts once the tree is dry (during dryer weather), do not prune when wet. Make sure that your equipment is thoroughly sanitized between each cut on the tree (even the same tree). Also make sure that your tree is well-watered at the roots during dry seasons, as the tree can become weaker and more vulnerable when it does not receive enough water.
