Blue spruce trees are one of the most valued trees in Michigan and the upper Midwest. The trees have so much to offer for landscaping, thanks to their aesthetic appeal. In addition to that, the trees play a significant role in improving the microclimate of an area.
Besides all the benefits, Michigan spruce trees face a wide range of challenges. These include diseases, pests, and adverse weather conditions that cause blue spruce trees to die. For that reason, it’s essential to learn how to tell if your blue spruce is dying or not. Here’s what to look out for:
Blue spruce trees are iconic evergreen conifers prized for their powder blue foliage. As spring arrives, these stately trees undergo an exciting transformation with the emergence of fresh new growth. Understanding the nature of this new foliage and properly caring for it ensures the health and vigor of blue spruce.
The Nature of New Growth on Blue Spruce
Blue spruce (Picea pungens) is a large conifer that can reach 60-100 feet tall at maturity in the right growing conditions. It maintains its blue-green evergreen needles through the winter. But when warmer spring weather arrives, new growth emerges from buds formed in the previous season.
These dormant buds swell and burst open revealing tender new light green shoots and needles. The new growth differs visually from the established darker blue foliage. As the new needles age over a couple months, they will transition to the typical blue-gray hue.
The spruce tree depends on this new foliage each spring to remain vigorous. The new needles are more efficient at photosynthesizing due to their optimal size and shape. The emerging shoots also increase total branch length and fullness over time.
Identifying New Growth on Blue Spruce
The fresh new needles and shoots of blue spruce are easy to spot against the older blue needles Look for
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Clusters of bright light green needles emerging together, while older singular blue needles sprout sporadically on branches
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Long and flexible new shoots rather than mature woody twigs
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Flushed new growth concentrated near branch tips and the upper half of the tree
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Waxy blooms coating new buds that protect the tender new growth
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Silvery fuzzy new buds that have just opened to reveal emerging frosted needle tips
Where New Growth Develops on Blue Spruce Trees
The location where new growth emerges follows a predictable pattern, allowing proper pruning and care.
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The most prolific new growth occurs near the top leader stem and upper branches where sunlight is maximized, fueling rapid growth.
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Lower and inner branches in the shaded canopy have slower growth rates and less new foliage.
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But branch tips farthest from the trunk still elongate slightly each year through new shoot growth.
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Heavy pruning stimulates multiple dormant buds to activate, resulting in bushier new growth.
Caring for New Growth on Blue Spruce
The tender new shoots and needles require proper care for health:
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Water deeply 1-2 times per week if rainfall is inadequate. New shoots are prone to dehydration.
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Provide sun protection like shade screens if newly planted until established. New growth can sun scald.
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Stake trees if needed to shelter new shoots from strong winds that can easily break them.
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Monitor for pests like spruce mites, adelgids, and sawfly larvae that feed on fresh new growth.
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Improve air circulation and avoid overhead watering to prevent fungal needle diseases that thrive on new needles.
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Fertilize with nitrogen in early spring to maximize new shoot growth. Avoid late summer feeding.
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Delay pruning until new growth has hardened off to prevent pest or disease entry points.
Significance of New Growth on Blue Spruce Health
The amount of new growth each spring directly correlates to the vigor and health of blue spruce trees.
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Trees with dense new shoots and needles are robust. Lack of new growth indicates low vigor.
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Long new shoots averaging 2-5 inches signal strength. Slow growing shoots under 1 inch show stress.
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Yellow needles indicate nutrient deficiency. Brown tips are sunscald. Wilting or spots mean disease. Vibrant green new growth is ideal.
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Look for abundant new buds forming on new shoots by early summer, ensuring next year’s foliage.
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If new growth is damaged, healthy trees will flush a second set. Weak trees struggle to recover.
New Growth Pruning Tips for Blue Spruce
Follow these guidelines when pruning new growth on blue spruce:
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Avoid aggressive shearing of new shoots. Allow them to elongate into their natural form.
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Remove no more than 1/3 of new shoot length when pruning. Heavy pruning causes dense growth prone to disease.
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For structural pruning, wait until new shoots harden off by mid-summer.
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Keep pruning minimal to sustain adequate new growth. Excessive pruning gradually depletes vigor over time.
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Concentrate pruning on areas like the lower canopy to direct vigor where desired. Remove competing leaders.
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Always make clean cuts just above a node, angled away from the nearest bud and avoid leaving stubs.
Enjoying the New Foliage Display
The springtime emergence of soft new green growth is an annual phenomenon to appreciate on blue spruce trees before it matures and darkens. Proper care focused on the delicate new needles and shoots will keep blue spruce healthy, allowing it to grace gardens with its signature beauty through the seasons.
Drying and Dying of Lower Branches
When you see lower branches of a blue spruce drying and dying, you should expect the worst. The main cause of drying of lower branches is cytospora canker. The fungus behind the disease lives under the bark and destroys vessels that supply nutrients and water to the branches.
When nutrients and water supplies are cut, the branches will dry out and eventually die. The condition worsens with time and moves up the tree. The tree will die after several years. White sap on the branches or trunk is another indicator of the disease.
This fungal disease affects mature Michigan spruce trees, mostly those older than 15 years. The disease is common when trees are planted too close to each other. Also, high moisture can stress trees which in turn make the trees weak and they will be more susceptible to disease.
Cytospora canker has no cure, but you can manage it through pruning. When pruning, you have to disinfect the pruning knife and the pruning cuts. Also, you have to get rid of the infected branches and needles in the right way as they may carry the fungus spores. You can also remove the infected trees and replace them with a different kind.
Needles Turn Yellow or Brown and Drop Off
It’s easy to tell whether your blue spruce trees are healthy or not. When you see that needles on many branches on the tree are turning yellow or brown, you should know that your tree is not well. The needles may eventually drop-off. Rhizosphaera needle cast may be the cause and can kill the tree in three or four years.
However, the disease is manageable if detected early. When you see such symptoms appear on your trees, you should contact a trusted arborist to help you save the trees. The disease spreads fast, and treating it early using the right fungicides can be of great help.
Planting the Most Beautiful Blue Spruce Trees! // Garden Answer
FAQ
What does new growth on a spruce tree look like?
The new growth is easy to identify because it is brighter in color and the needles are soft. Picking spruce tips from a standing tree is a good exercise in self-control and judgment. Every tip that’s picked is pruning the tree.
What is the weird growth on my spruce tree?
No, the caller’s tree wasn’t sick, not exactly. Those prickly, cucumber-shaped growths that show up on spruces from time to time are actually galls caused by an insect. They might look peculiar, but they weren’t going to cause significant harm to his spruce.
Will blue spruce grow new branches?
If every time you prune your spruce tree, each pruning spot develops into two or three new branches, you will thus develop a nice full tree.