Content
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 is 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, however, a slight color change 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 range 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 anthocyanin not only in autumn. This is a natural reaction of the plant to the deterioration of weather conditions, therefore, a change in the color of the needles is observed, for example, in dry weather. Sometimes in a juniper, the needles turn yellow in the fall and fall off due to the withering away of the old needles and replacing it with new ones. This is a natural process that occurs approximately once every 4 years.
Reasons why juniper turns yellow in the garden
There may be several reasons why the 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 to immediately find out what is happening with the bush. To do this, they conduct a full examination of junipers, do analyzes of soil, water, check for diseases and pests.
Incorrect 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 your juniper is of great importance. In the wild, this shrub most often grows in light pine or deciduous forests, along roadsides, on clearings and forest edges. The best place for him is partial shade, so an area that is too shady will not work for him. The acidity of the soil should be close to neutral. And the juniper reacts very negatively to excess moisture, therefore, it is strictly not recommended to plant it on a swampy area.
The time of planting the juniper in open ground is also important. You should not do this 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.
Special attention should be paid to junipers taken from the wild. They take root, as a rule, very poorly, therefore, in most cases, the bush brought from the forest will turn yellow, dry and, in the end, die. Juniper plantings in most regions are protected, this also needs to be borne in mind. 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, as a rule, there is enough natural rainfall for it. An exception is made only during dry periods, when it is recommended to carry out not only watering at the root, but also irrigation of the crown.
Another reason for the yellowing of juniper needles is associated with spraying the bush. If you irrigate in bright sunny weather, then the plant is guaranteed to get burned, especially from 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 droplets. In sunny weather, they become a kind of lens that focuses light and can burn through the leaves. Therefore, in clear weather, juniper irrigation 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 the 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 limescale the soil. You should also protect junipers from pets peeing in trees, as their urine has a strong alkaline reaction. Plants are recommended to be fenced off with a net, trellis or special deterrent agents.
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. In such conditions, even well-drained soils can turn into a swamp, and this is detrimental to this shrub. Prolonged dry periods can also cause crown yellowing, especially when combined with dry, hot winds.
Pests
Junipers are often subject to pest infestations, especially in the southern regions. Often insects settle in the crown and feed on leaf juices. Due to a lack of nutrients, the needles turn yellow and die off, and in especially severe cases, the tree may die.
The most famous insect pests of juniper are listed in the table:
Pest | The nature of the defeat | Ways to combat and prevent the appearance |
Aphid | Aphids suck the juice from young needles, causing them to turn yellow and die off. | Cutting off young shoots with aphid colonies. Flushing 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 close proximity to shrubs repelling plants, such as pyrethrum. |
Shield | Parasitizes on shoots and needles of juniper, sucking out juices. With a large population, scale insects are able to kill shrubs. | Treatment of the crown with special preparations, for example, Aktara, Actellik or Karbofos. Severely affected shoots are cut and burned. The crown can be treated with a mild solution of laundry soap and then rinsed with clean water. |
Needle mite | It feeds on juices of young needles, which turn yellow due to lack of nutrients. It is found by the 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 processing the crown with a solution of laundry soap, followed by rinsing with clean water. |
Miner moth | A pest butterfly whose caterpillars gnaw needles from the inside. | Treatment with the drug Decis 2 times with an interval of 25 days.Autumn digging of near-trunk circles and soil treatment with fungicides. |
Angle-winged moth | A pest butterfly, she and her caterpillars feed on needles. | Spraying with Decis-Profi, Actellik or Fufanon preparations. Damaged shoots are removed. |
Diseases
Juniper gets sick quite often, especially if it grows in unsuitable conditions. Here are the most common diseases found in this shrub.
Disease | The nature of the defeat | Treatment and prevention methods |
Fusarium wilting (fusarium) | 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 moisture. Prevention is the culling of seedlings and mature plants, as well as planting in a more suitable place. Diseased plants are immediately removed and burned. As a preventive measure, the juniper is sprayed with Vitarox or Baktofit preparations, and the soil is impregnated with Fitosposrin solution. |
Drying of shoots | The infection is caused by fungi that live on the bark of the tree. The affected shoots turn yellow and dry up, the needles fly around. | Infected shoots are pruned and burned. The crown must be treated with a 1% solution of copper sulfate. |
Schütte (brown gray mold) of 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 tint. | To reduce the likelihood of the onset of the disease, it is necessary to prevent thickening of the plantings and excess moisture. There is no cure for shute. 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 the 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. | The affected branches must be cut and burned. As a prophylaxis, juniper is treated with Bordeaux liquid in spring and autumn. |
Bark necrosis | 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. The affected branches are cut and burned. The soil in the root zone is spilled with Fitosporin solution. |
Biotorellic cancer | The fungus develops in cracks in the bark. After a while, the bark turns brown, the needles turn yellow and the shoot dies off. | If a fungus is found, the affected shoots must be cut off and burned. As a preventive measure, plants are treated with Hom or Abiga-Peak preparations. |
Influence of seasons on plant yellowing
Although juniper is an evergreen shrub, its color may vary depending on seasonal factors. This applies to both species growing in the wild and ornamental garden shrubs.
Why does juniper turn yellow in summer
The yellowing of junipers in 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 improper care. If the yellowing or browning is of a local or focal character, 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 does juniper turn yellow in autumn
Uniform color change of juniper with decreasing temperature in autumn is a natural process. The amount of anthocyanins produced in the leaf plates increases, changing the color of the needles and giving them a golden or reddish-brown hue.
In early autumn, the juniper often turns yellow on the inside.This dies off part of the old needles, the age of which is several years. Thus, there is a natural process of replacing her with a young one. In this case, the color change is uniform and appears only on the inside of the needles.
Why does juniper turn yellow after winter or 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 adhered snow. Frozen and broken branches will begin to turn yellow. In the spring, they need to be removed first, otherwise they will become breeding grounds for diseases and a home for insect pests.
Why does juniper turn yellow in spring
The most common cause of juniper crown yellowing in spring is sunburn. This is due to the fact that under the influence of direct sunlight, the coniferous cover heats up. Snowflakes adhering 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 become brown. To protect shrubs from sunburn, they are usually covered with a layer of gauze.
What to do if juniper turns yellow and dries
To determine the reason why the juniper turns yellow or brown and begins to dry out, you need to carry out, first of all, a complete examination of it 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 rather difficult to notice it on the shoot.
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 agent and dilute them in 5 liters of water. The solution is abundantly sprayed on the crown of the juniper. You can do this several times at intervals of 3-5 days.
Juniper reacts quite strongly to the gas pollution of the atmosphere, so it is not used for landscaping streets. In areas located near industrial areas or along busy highways, problems with yellow tips of juniper needles can be directly related to poor environmental conditions. It is unlikely that it will be possible to correct this situation, so for planting juniper it is worth looking for another place, and planting something more resistant to the 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 out of the soil in the root zone, then this indicates insufficient watering. It is highly recommended to mulch the tree trunks as it retains moisture well in the soil. It will not be superfluous to check the acidity of the soil once again. This can be done using a test that can be purchased at the store.
Preventive actions
Prevention is the best way to avoid yellowing problems in juniper needles. The shrub must be regularly treated with fungicides to prevent fungal diseases. In addition, you need 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. Neglected diseases are treated much worse and in most cases lead to the death of the plant.
An important measure is the comprehensive care of the juniper tree trunks. Weeding, loosening and mulching, as well as processing with special preparations is an excellent preventive measure 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 spring, measures should be taken to shelter the juniper from the bright sun. Young bushes and seedlings must be protected from direct sunlight in the first place. For this, it is better to use burlap. A covering material cannot be used for this purpose, since it prevents the evaporation of water. Sometimes, for protection 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, you must immediately examine it and identify the cause. The sooner you do this, the more chances you have to return the shrub to a healthy decorative look. 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.
