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Various varieties of juniper are widely used in ornamental gardening and landscaping. This coniferous shrub remains green at any time of the year, it is quite unpretentious and rarely affected by diseases that can spoil its appearance. However, he also has problems with the crown. If the juniper has turned yellow, you need to deal with it and look for the reasons.
Does juniper turn yellow in autumn
The natural color of juniper scales or needles is green. So it remains in the fall, but a slight change in color still occurs. This is due to the fact that juniper leaves synthesize anthocyanins – specific wax-like compounds that protect the tree from ultraviolet radiation. Their colors can vary from red to purple. In combination with the green of the needles, they give it a yellowish or brownish tint.
Juniper leaves turn yellow due to the release of anthocyanins, not only in autumn. This is a natural reaction of the plant to worsening weather conditions, so a change in the color of the needles is observed, for example, in dry weather. Sometimes the juniper needles turn yellow in autumn and fall off due to the death of the old needles and its replacement with a new one. This is a natural process that occurs approximately once every 1 years.
Reasons why the juniper turns yellow in the garden
There may be several reasons why juniper turns yellow. The most common are the following:
- Wrong choice of landing site.
- Violation of the rules of care.
- Disease.
- The appearance of pests.
Often there are several reasons for the yellowing of the crown. Therefore, it is necessary without delay to find out what is happening with the bush. To do this, a complete inspection of junipers is carried out, soil and water analyzes are done, and the presence of diseases and pests is checked.
Wrong fit
Juniper often turns yellow after planting. This means that the site or soil is not fully suitable for it. Choosing the right place to plant juniper is important. In the wild, this shrub most often grows in light pine or deciduous forests, along roadsides, clearings and edges. The best place for him is partial shade, so a too shady area for him will not work. Soil acidity should be close to neutral. And the juniper reacts very negatively to excess moisture, so planting it in a wetland is categorically not recommended.
The time of planting juniper in open ground is also important. It should not be done in the heat, in the middle of summer. The best time for planting is spring, April-May, as well as the first half of autumn, September or early October.
Particular attention should be paid to junipers taken from the wild. They take root, as a rule, very poorly, therefore, in most cases, a bush brought from the forest will turn yellow, dry and, in the end, die. Juniper plantings in most regions are protected, this must also be remembered. Therefore, it is better to take plants from specialized nurseries. Such species take root much better and require less maintenance.
Improper care
Juniper is quite unpretentious, however, violations in care can also cause yellowing of its crown. Most often this is due to insufficient watering. This is especially true for species that are grown under cover or at home. If the shrub grows in open ground, then natural precipitation is usually enough for it. An exception is made only during dry periods, when it is recommended to carry out not only watering under the root, but also irrigation of the crown.
Another reason for the yellowing of juniper needles is associated with spraying shrubs. If you irrigate in bright sunny weather, the plant is guaranteed to get burned, especially on the sunny side. Since juniper leaves have a waxy coating, they are not completely wetted, and water remains on them in the form of small round drops. In sunny weather, they become a kind of lens that focuses light and can burn through the leaves. Therefore, irrigation of the juniper in clear weather is done only late in the evening or early in the morning, so that all the water on the foliage has time to dry completely.
The composition of the soil on which juniper grows is also important. Too large deviations of acidity in one direction or another negatively affect the color of the crown. Therefore, you need to be careful when applying fertilizers so as not to acidify or, conversely, not to lime the soil. Juniper should also be kept away from pets urinating on trees, as their urine is highly alkaline. It is recommended to enclose plants with a net, a lattice or use special repellents.
Unfavorable climatic conditions
Unfavorable climatic conditions can affect the appearance of the juniper and the condition of its crown. Such problems can arise if the summer, for example, is too cold and rainy. Under such conditions, even well-drained soils can turn into a swamp, and this is detrimental to this shrub. Long periods of drought can also cause yellowing of the crown, especially in combination with dry hot winds.
vermin
Juniper is quite often subjected to pest invasions, especially in the southern regions. Insects often settle in the crown and feed on the juices of the leaves. Due to a lack of nutrients, the needles turn yellow and die, and in especially severe cases, the tree may die.
The most famous juniper pests are listed in the table:
Pest | The nature of the lesion | Ways to combat and prevent the appearance |
aphid | The aphid sucks the juice from the young needles, causing it to turn yellow and die. | Cutting young shoots with aphid colonies. Rinsing with water pressure. Spraying 2 times during the season with Fitoverm or Karbofos preparations, as well as folk remedies: infusion of garlic, tobacco or horseradish. Planting in the immediate vicinity of a shrub repellent plants, such as feverfew. |
Shield | It parasitizes on the shoots and needles of juniper, sucking out the juices. With a large population of scale insects, they can kill shrubs. | Crown treatment with special preparations, for example, Aktara, Aktellik or Karbofos. Severely affected shoots are cut and burned. The crown can be treated with a weak solution of laundry soap, and then rinsed with clean water. |
Needle tick | It feeds on the juices of young needles, which turn yellow due to a lack of nutrients. It is found by characteristic thickenings at the ends of the needles. | Spraying with Karate or Akarin preparations. Periodic spraying with infusions of garlic or tobacco, as well as treating the crown with a solution of laundry soap, followed by rinsing with clean water. |
Minimizing Mole | A pest butterfly whose caterpillars gnaw out needles from the inside. | Treatment with Decis 2 times with an interval of 25 days. Autumn digging of tree trunks and soil treatment with fungicides. |
Angled Moth | Butterfly pest, she and her caterpillars feed on needles. | Spraying with Decis-Profi, Aktellik or Fufanon. Damaged shoots are removed. |
Diseases
Juniper gets sick quite often, especially if it grows in inappropriate conditions. Here are the most common diseases found on this shrub.
Disease | The nature of the lesion | Methods of treatment and prevention |
Fusarium wilt (Fusariosis) | Yellowing and falling of needles, drying of shoots, starting from the top of the plant. Caused by soil fungi that cause root rot. | The infection appears when choosing the wrong place for planting or due to natural factors: insufficient lighting and excessive humidity. Prevention is the culling of seedlings and adult plants, as well as planting in a more suitable place. Diseased plants are immediately removed and burned. As a preventive measure, juniper is sprayed with Vitarox or Bactofit preparations, and the soil is impregnated with Fitosporin solution. |
Shrinkage drying | The infection is caused by fungi that live on the bark of the tree. The affected shoots turn yellow and dry out, the needles fly around. | Infected shoots are cut and burned. The crown must be treated with a 1% solution of copper sulfate. |
Schütte (brown gray mold) juniper | The causative agent of the disease is a fungus that primarily affects needles and young shoots. The affected branches turn brown, but the needles do not fly around, but acquire a reddish-brown hue. | To reduce the likelihood of the occurrence of the disease, it is necessary to prevent thickening of plantings and excess moisture. There is no cure for schutte. The affected plant must be dug up and burned. As a preventive measure, the shrub is treated with Bordeaux liquid twice a year. |
Rust | One of the most common diseases of juniper. It is caused by fungi that appear on shoots, bark, cones. Determined by the appearance of bright yellow or orange growths on the bark. | Affected branches must be cut and burned. As a preventive measure, juniper is treated with Bordeaux liquid in spring and autumn. |
Necrosis is dry | Appears on shoots in the form of small brick-colored pads. Over time, the affected juniper dries up. Necrosis can also affect the roots of the plant. | As a preventive measure, plants are treated with Fundazol. Affected branches are cut and burned. The soil in the root zone is shed with Fitosporin solution. |
Biotorell cancer | The fungus develops in cracks in the bark. After a while, the bark turns brown, the needles turn yellow and the shoot dies. | If a fungus is found, the affected shoots must be cut and burned. As a prophylaxis, plants are treated with Hom or Abiga-Peak preparations. |
The influence of the seasons on the yellowing of the plant
Although the juniper is an evergreen shrub, its coloration can change depending on seasonal factors. This applies to both species growing in the wild and ornamental garden shrubs.
Why juniper turns yellow in summer
Yellowing juniper in the summer is most often associated with insufficient watering. If the crown has faded and begins to turn yellow evenly, the cause must be sought precisely in the wrong care. If yellowing or browning is local or focal in nature, individual branches, shoots or sections of the crown change color, then it is necessary to check the plant for the presence of a disease or the appearance of pests.
Why juniper turns yellow in autumn
A uniform change in the color of juniper when the temperature drops in autumn is a natural process. The amount of anthocyanins produced in leaf plates increases, changing the color of the needles and giving it a golden or reddish-brown hue.
In early autumn, juniper often turns yellow inside. This dies off part of the old needles, which are several years old. Thus, a natural process of replacing it with a young one takes place. In this case, the color change is uniform and appears only on the inner part of the needles.
Why juniper turns yellow after winter or in winter
In winter, juniper leaves turn yellow for the same reasons as in autumn. An additional reason may be damage to the crown by severe frosts or mechanical injury to the bush under the weight of adhering snow. Frozen and broken branches will begin to turn yellow. In the spring, they must be removed first of all, otherwise they will become breeding grounds for diseases and a home for pests.
Why juniper turns yellow in spring
The most common cause of yellowing of the juniper crown in spring is sunburn. This is due to the fact that under the influence of direct sunlight, the coniferous cover heats up. Snowflakes sticking to the branches melt, turning into water droplets. Each of these droplets becomes a magnifying glass that focuses the sun’s rays. Therefore, quite often in early spring, from the sunny side, junipers literally burn out, the needles turn yellow or turn brown. To protect shrubs from sunburn, they are usually covered with a layer of gauze.
What to do if the juniper turns yellow and dries
To determine the reason why the juniper turns yellow or brown and begins to dry out, it is necessary to carry out, first of all, its complete examination for the presence of diseases or pests. This must be done very carefully, because, for example, the scale insect is skillfully disguised and it is quite difficult to notice it on the run.
Slight yellowing of juniper needles can often be eliminated by spraying the plant with an aqueous solution of Epin with the addition of Zircon. To prepare such a stimulant, you need to take 1 ampoule of each remedy and dilute them in 5 liters of water. The juniper crown is abundantly sprayed with the solution. You can do this several times with an interval of 3-5 days.
Juniper reacts quite strongly to the gas content of the atmosphere, so it is not used for landscaping streets. In areas located near industrial areas or along busy highways, problems with the yellow tips of juniper needles can be directly related to poor environmental conditions. It is unlikely that this situation will be corrected, therefore, for planting juniper, it is worth looking for another place, and planting something more resistant to polluted atmosphere on the site.
It must be remembered that the soil on which this evergreen shrub grows must be constantly moist, but not swampy. If every day there is a clear drying of the soil in the root zone, then this indicates insufficient watering. It is strongly recommended to mulch the trunk circles, this retains moisture well in the soil. It would be useful to once again check the acidity of the soil. This can be done using a test, which can be purchased at the store.
Preventive measures
Prevention is the best way to avoid juniper needle yellowing problems. The shrub must be regularly treated with fungicides to prevent fungal diseases. In addition, it is necessary to regularly inspect it, and this must be done scrupulously and carefully. If a disease or pests are detected at an early stage, then, as a rule, it is possible to save the shrub. Advanced diseases are treated much worse and in most cases lead to the death of the plant.
An important event is the comprehensive care of juniper tree trunks. Their weeding, loosening and mulching, as well as treatment with special preparations, is an excellent prophylactic against the appearance of pests wintering in the root zone. Trunk circles, like the shrub itself, must be regularly cleaned of old wood, dry and broken branches.
In the spring, measures should be taken to shelter the juniper from the bright sun. Young bushes and seedlings must be sheltered from direct sunlight in the first place. For this, it is better to use burlap. Covering material should not be used for this purpose, as it prevents the evaporation of water. Sometimes, to protect from the sun, it is enough to install a small screen or a white screen that protects the juniper from direct sunlight.
Conclusion
If the juniper has turned yellow, it is necessary to immediately examine it and identify the cause. The sooner this is done, the more likely it is to return the bush to a healthy decorative appearance. Juniper is a magnificent ornamental shrub that has a lot of useful properties. Therefore, do not let the situation take its course. It is always better to understand and identify the causes of yellowing of the needles in order to avoid this in the future.
