Blue spruce trees are beautiful evergreen trees with a tint of blue to their needles. Some trees look bluer than others which is the result of primarily tree maintenance and fertilizer. What steps can you take to make your blue spruce look more vibrant and blue?
In general, positioning your blue spruce in full sun exposure can help the tree appear more blue. More sun allows for more photosynthesis to occur, making the blue spruce pigments more concentrated. Additives like fertilizers can also increase the hue of your blue spruce.
Read on to learn more about how blue spruces grow, what they need to grow, and ways you can make them more healthy, vibrant, and of course, blue!
Basics of Blue Spruce Trees
If you are trying to understand why your blue spruce is not fully blue, you first need to know the basics: what they need, what they want, and what makes them blue.
What Do Blue Spruce Trees Need To Be Blue?
There are a few necessities your blue spruces need to grow full and healthy. Some of these include having moist, well-drained, and fertilized soil.
To start, blue spruces like to have moist soil. If you are in an area that receives regular rainfall (approximately 1 inch a week), you should be fine. However, if you are in a dryer area, you may need to hand water, or set up an irrigation system.
Blue spruces want more well-drained soil as compared to other plants and trees. This means that you want to find soil that has larger, looser components, such as sand, compost, and organic matter. These will act to make your soil more workable for the roots of the spruce and create a natural water control system.
Spruces also prefer very fertile soil. In most residential areas, where the soil has lower quality, you will most likely need to incorporate some type of fertilizer. You might use compost, organic granules, or a pre-mixed liquid. This can help the health of the soil and your other plants.
Maintaining Blue Spruce Health
Besides meeting your tree’s needs, it is important to maintain its health. Spruce health is strongly correlated to its appearance, so one reason your spruce may not be as blue as you would like could be because it is not as happy as it should be.
In terms of watering, spruces want around an inch per week. This can vary to a certain extent, but it is important to know that your spruce would prefer occasional heavy watering compared to small, frequent waterings.
Along with watering and maintaining spruce needs, you should also maintain spruce health by monitoring its outward appearance. Periodically checking if your spruce has dulling needles, algal spots, or falling needles, can help you assess and maintain its health.
What Causes Blue Spruces To Be Blue?
So, the question of the day. Just why are blue spruces blue?
In truth, the blue color of blue spruce needles is mainly attributed to epicuticular waxes found on the outside of the needles. This wax reflects sunlight in certain wavelengths that appear to us as a frosty blue. Pigments within the needles, chlorophyll for example, also make a blue spruce more blue.
To explain this in more depth, the plant cells in blue spruce needles create exudate (wax) that coats the needles, leaving a waxy exterior. Therefore, blue spruce needles are often thick, waxy, and leathery on the outside.
This wax acts to insulate and protect the needle from outside stimuli, such as poor weather conditions.
The waxy coating naturally reflects certain wavelengths of visible light, causing us to perceive them as a frosty blue color. Increasing or supporting your tree’s production of this wax can act to increase and maintain its proper blue color.
Next, we’re going to talk about just why your blue spruce may have lost it’s color, and then get into how you can make it more blue again!
Reasons Blue Spruces Lose Their Color
There are a multitude of reasons your blue spruce might lose its iconic blue color. Pollutants and other natural causes in the air can make the wax coating deteriorate, causing spruces to lose their color. Certain fungal diseases or improper care can also cause a loss of blue spruce color.
To elaborate on air pollutants, we’re referring to specific compounds such as nitrogen oxides, carbon particulates, and hydrocarbons.
These are all things associated with bad air quality and C02 emissions. There is not a lot you can do to help this, other than making sure your tree is healthy and you are supporting your native wildlife.
Specific fungal diseases and infections can also cause blue spruces to lose their iconic color. While some of these diseases affect the needles themselves, a lot is actually in the rhizosphere (root zone) of your tree, so you should target remedies towards your roots.
As with most plants, improper care can cause your blue spruce to lose its luster. To start, if your tree is not getting enough water, nutrients, etc., it most likely won’t have enough storage to maintain and create the blue wax.
If your tree is being improperly watered or cared for, this can also cause the needles to yellow or fall off, which certainly affects how blue your spruce appears.
Did you know that blue spruce trees are one of the trees that keep their leaves year round?
How To Make Your Blue Spruce Tree More Blue
Now you know what blue spruces are like, what causes them to have a blue color, and what can affect this blue color. We can look at some simple steps to making your spruce appear bluer.
To preface, these steps aren’t in any chronological order. Instead, they are separate tips you can pair and use together to help your specific tree.
Boost Blue Spruce Color With Proper Environmental Conditions
To begin, one of the best ways to boost the color of your blue spruce is to make sure that it has the right conditions, such as light, temperature, and moisture levels. The most important factor is usually light, as that is the ultimate source of energy for plants and trees.
Light allows spruces to create sugars and energy, which it then uses to carry out functions like creating and maintaining the waxy coating of needles. This means that maintaining proper sun exposure can help your spruce in creating and maintaining a blue color in your blue spruce.
Maintaining high light exposure and proper soil conditions also causes the needles to be shorter because they have to cover less area for the same amount of sun. This allows the waxy covering to concentrate over a smaller needle, making your tree appear bluer.
There are other factors, such as temperature and wind, among others.
While these are important, they have less of an impact on spruce color as compared to sunlight. Simply keeping these factors stable and consistently in the range that your spruce likes could be all you need!
Protect Blue Spruce Wax Coating To Increase Blue Color
One small thing to mention about your spruce’s color is protection. While the waxy coating is fairly stable and relatively water-proof, some things can physically remove it from your tree.
Very heavy and consistent rains can wear down this wax over time, and reduce the wax on the blue spruce tree, which protects it and causes it’s blue color. Areas with less rain in the summer can allow it to maintain its blue color for longer.
Other conditions, such as wind and animal activity, can also remove the wax, so look into things such as repellents or planting wind barriers to protect the coating!
A decrease in wax can also lead to stunted growth, which is a reason why your pine tree (blue spruce) isn’t growing.
Blue Spruce’s Need Time To Regain Their Blue Color
One of the best tools to fix most problems is to give them time. Similarly, with the blue color of spruces, one of the best ways to help them is to give them time. As with most things, it takes time to grow new needles and create new wax.
You may simply want to give your spruce more time to see if it can bounce back to its blue color on its own. This can be beneficial, as sometimes we can hurt our plants and trees by doing too much for them. Pruning, fertilizing, and watering could cause harm while attempting to help them.
In other words, if your tree is healthy, try to let it sort itself out!
Other than letting more wax develop, another reason to give your blue spruce more time is that it allows them to grow more needles. In most cases, new needles have an incredibly high concentration of this wax on them, making them appear extra blue.
If you allow your tree to grow new blue needles, you may have more luck in caring for them so that they retain their color for as long as possible.
Fertilizers Can Regain Blue Spruce Color
While this is less researched, many people claim that using fertilizers can help maintain or turn your spruce bluer.
Fertilizers are usually a good idea for your plants in any situation, as they add a boost of vitality to the soil that improves biodiversity, soil health, and the overall nutrition of your plant. Fertilizers could help restore some blue color by giving plants the nutrients used to make the wax coating.
While most fertilizers will do the trick to help plants, some situations require specific remedies. Most people have selected fertilizer options that they claim will help maintain your spruce’s blue color.
Many claims in favor of using some sort of fertilizer rich in iron have been made. This might help to give your tree its blue color back because we see many forms of iron as a blue color, and iron is a component of many waxed spruce needles.
Another reason people recommend iron is because it combats things such as chlorosis, which causes yellowing or whitening of leaves and needles. One great example of an iron agent you can add is this 4-lb Iron Sulfate.
If your tree needs an all-around nutrient boost, look into specialty all-purpose fertilizers, such as Scott’s Evergreen Flowering Tree & Shrub Fertilizer. Blue spruces, are in the evergreen family of trees. This fertilizer releases nutrients straight into the root zone of your tree, promoting good health all season long!
Fix Blue Spruce Fungus To Regain It’s Blue Color
Along with adding things to your tree, assess the physical health of your tree. This means figuring out if you are meeting its required water and sunlight needs. It also means finding out if it is healthy, or if it has a certain infection or fungal disease.
Many diseases can affect your spruce tree, each with its causes and appearances.
One common disease among spruces is a needle disease brought on by the fungus “Rhizopheara.” This is often referred to as Rhizosphaera Needle Cast. According to Nebraska Extension, this disease normally stays on living or recently dead needles and can cause your tree’s needles to darken, turn brown, or even fall off.
If your tree was recently transplanted or has gone through some sort of shock, like inclement weather, it may be more susceptible to this disease.
To prevent or treat your blue spruce, identify the certain problem on your tree, if there’s any clear bark, needle, or nearby grass issues. Research or call an expert, and apply the proper fungicide or recommended tactic.
In the end, while this isn’t the only disease that can affect your blue spruce, it is a good example of how diseases show on trees, what they do, and some ways to treat them.
Maintain Good Care Of Your Blue Spruce To Keep It Blue
While we have mentioned this before, the best way to have your blue spruce get a blue color is simply to find a correct care technique and stick to it.
In the end, your tree has the genetics to be blue, so as long as you properly care for it, it should have enough energy and components to stay blue.
By proper care, people normally refer to basic needs, so you should find what your specific spruce wants in terms of water, sunlight, soil type, temperature, nutrients, etc.
Some spruces benefit from occasional pruning. This can help them get rid of old or dead growth, and make space and energy for fresh growth to come in.
This is especially true in trees with dead growth or fungal damage because pruning can help prevent spread!
That’s A Wrap!
In the end, blue spruces can be very rewarding to grow. They are magnificent and can add the perfect whimsical pop of blue to your garden all year long.
Blue spruce trees have some special care requirements. If they are not met, it can lead them to change or lose their color. This color is caused by a wax coating they create, meaning you can specifically try to increase its production to make your tree bluer!
A few of the methods you can use to make your spruce bluer are to add iron fertilizers, monitor its health, and have it in a location with full sun exposure. These methods act to keep it healthy, allowing it to create and maintain its wonderful blue color.
Overall, while keeping your spruce blue may be important, it is always good to remember to have fun while out in your garden, and to connect to your trees!
Kangas, M. (2004). Spruce Diseases In North Dakota [E-book].
Hanover, J. W. (1975). Genetics of blue spruce (Vol. 28). Forest Service, US Department of Agriculture.
van HavVan Haverbeke, D. F. (1984). Genetic variation in blue spruce: a test of populations in Nebraska (Vol. 253). Rocky Mountain Forest and Range Experiment Station, Forest Service, US Department of Agriculture.