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Why blue spruce turns green: causes and what to do, tree treatment methods

Why blue spruce turns green: causes and what to do, tree treatment methods

The blue spruce is a fairly popular ornamental plant that comes from North America. This culture is distinguished by a beautiful bloom on the needles. Due to this, the tree appears gray-green or bright blue. Because of this, the plant is often used in landscape design. At the same time, sometimes the needles change their color. However, not everyone knows why the blue spruce turns green.

What determines the color of the tree

The blue color of the needles is associated with the presence of a wax coating on its surface. To protect against moisture loss and ultraviolet radiation, conifers produce special substances.These include phenolic elements, ascorbic acid, pigments. Such components not only have protective functions, but also give the tree a blue color.

In autumn, the need for such protection decreases. Therefore, the process of formation of the protective layer slows down. At this time, the blue color becomes less pronounced, and the plants acquire a greenish tint. In the spring, the formation of a protective layer is activated, and the trees get a more intense blue color.

Why is it changing

Sometimes you can see that the blue spruce has turned green. There may be several reasons for such changes.

Seasonal changes

One of the main reasons for color changes are natural features. So, the shade of the needles depends on the season. In summer, spruces are blue, and by spring they turn green.

Also, the needles of young shoots have a bright green color. After some time, the annual growth is covered with a wax coating and acquires a blue tint. At the same time, the needles become stiffer.

Different shades of needles, associated with the age of the shoots, lead to a very unusual appearance of the tree itself. An example is the Bialobok spruce. At certain times of the year, its needles have 3 different shades. Immediately after the appearance of the needles, they have a white-yellow color, after a few weeks they become greenish, and subsequently blue. That is why, at certain periods of time, the Bialobok spruce acquires a tricolor color.

Thus, the change in the color of the needles does not always indicate problems with the development of culture. In order not to worry about her condition, when buying a seedling, you should definitely clarify the features of the development of culture.

Wrong feeding

Sometimes the reason for changing the color of conifers is considered to be violations of the rules of care - in particular, improper fertilization. The blue color of spruce is lost due to magnesium deficiency.If such a problem is observed, it is recommended to feed the spruce with magnesium sulfate. In this case, 20 grams of the substance should be mixed with 1 bucket of water. The resulting solution is recommended to water the tree. This is required to be done at the root. The needles themselves should be sprinkled with the Zircon growth stimulator. To prepare a he althy solution, it is recommended to take 1 gram of the drug per 10 liters of water.

Many conifer fertilizers include magnesium s alts and sulfur. With the help of magnesium, it is possible to avoid changing the color of the needles, and sulfur has an acidifying effect on the soil. This feature must be taken into account. If the soil on the site is already acidic, then preparations containing sulfur may acidify it too much.

Bad landing site

It is important to consider that the saturation of the bluish hue depends on the place where the crop grows on the site. Almost all conifers with a decorative color prefer areas well lit by the sun. Of course, they will grow in the shade, but gradually the blue color will turn into standard green.

If the wrong choice of planting site has caused a change in the color of the tree, you can transplant it to a more suitable site. The root system of the tree develops in breadth, therefore, the culture should not be dug along the perimeter of the crown, but retreat another 50 centimeters from it.

The procedure is recommended to be carried out with a pitchfork, not a shovel. This will help avoid damage to the root system. Thanks to the use of a pitchfork, it will be possible to pull out a spruce with a lump of soil and move it to a new planting hole. When transplanting, it is important to monitor the location of the branches. The southern shoots should be directed south again, and the northern shoots should be directed north.


Blue spruces suffer from a range of diseases. However, most often they are prone to fungal infections. The most common pathologies are provoked by the fungi Rhizosphaera kalkhoffii and Kabatina.

Besides this, blue spruce suffers from the following pathologies:

  1. Ulcerative cancer - in this case, ulcerative defects and swelling are formed on the shoots and bark. They disrupt the access of oxygen from the needles.
  2. Necrosis - in this case, red growths form on the trunk and shoots. Over time, they provoke the complete death of the tree.
  3. Schutte - is a rather dangerous fungal disease. At the same time, a brown schütte of early spring is distinguished, an ordinary one, which occurs at the end of spring, and a snow one, which develops in autumn.
  4. Tracheomycosis - provokes damage to the roots of spruce.

To avoid the development of dangerous pathologies, you must adhere to the following rules:

  • spray and water the plant with fungicides;
  • use preparations containing copper;
  • delete affected branches;
  • destroy diseased plants;
  • sprinkle the trunk circle with ash.

How to stop it

In order for spruce needles to retain their attractive appearance, the tree needs to be fully cared for. To do this, do the following:

  1. Make sure the spruce is located in a well lit area with good drainage.
  2. Use enough water to maintain optimum soil moisture. In this case, the trunk circle should be covered with mulch. This will help keep it hydrated longer.
  3. Apply magnesium-based products under the tree. For top dressing, magnesium sulfate can be used. To do this, 20 grams of the substance must be mixed with 1 bucket of water and watered under the root of the plant.

Blue spruce is a fairly common ornamental culture, which is often used to decorate garden plots. In order for the tree to retain an attractive color of needles, it is important to clearly follow all agrotechnical recommendations.

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