What to do if fir turns yellow

Fir is an evergreen tree that adorns city parks and gardens. Although the plant is considered unpretentious, it, like any culture, needs care, protection from diseases and pests. Fir diseases and other adverse factors lead to yellowing and shedding of its needles. As a result, the tree loses its decorative appearance and slowly develops. If measures are not taken in time, the plant may die.

Why fir turns yellow

When fir needles turn yellow, the first thing they pay attention to is the place of cultivation. For the plant, choose a site in partial shade with fertile moist soil. If the planting rules are violated, then the fir develops poorly and loses its decorative properties.

Causes of yellowing fir after planting:

1. The order of work is broken. When planting plants take into account the shrinkage of the soil. It is best to dig a hole in advance and leave it for 2 to 3 weeks. During work, it is not recommended to bury the earthen ball and the root collar. With a low landing, a small depression forms over time, where moisture accumulates. The root neck gets wet, which eventually causes fungal diseases.
2. nearby plants. Fir is not planted next to large trees that take a lot of moisture and nutrients from the soil: such as linden, oak, maple, fruit crops. A distance of 3-5 m is maintained between the trees. If the crops are planted close, then more moisture and minerals are added.

   

3. Soil quality. Fir grows best in loamy soil. The soil must be moist and fertile. On poor soils, conifers lack nutrients. In sandy soil, the tree will not receive enough moisture, and in clay soil it will suffer from its excess.
4. seedlings. When buying, pay attention to the quality of planting material. Seedlings are chosen at the age of 2 – 4 years, without cracks, rotten areas and other defects. The earth ball must remain intact. Otherwise, the fir does not take root well and is subject to disease.
5. Watering. With a lack of moisture, the growth of fir stops, and the needles turn yellow and begin to fall off. With an excess of moisture, the roots receive little oxygen, as a result of which fungal diseases develop.
6. Freezing. Young fir may turn yellow after spring cold snaps. If frosts are coming, the conifers are covered with agrofiber or other material.

Fir diseases and their treatment

Yellowing of the needles is also caused by many fungal and cancerous diseases. The first group of lesions appears at high humidity. To combat them, special drugs are used. The most dangerous cancers are those that cannot be cured.

Needle diseases

The main diseases of fir with a photo:

• Rust. The fungus that provokes the disease spreads to the lower part of the shoots. As a result, rows of yellow-orange bubbles up to 4 cm high are formed. Gradually, the lesion covers all branches. Often the infection gets on fir from other plants – lindens and lingonberries. The disease is most dangerous for young conifers;

  

• Brown coat. Fungal disease that affects different types of fir. Its symptoms appear immediately after the snow melts. The needles are covered with a dark brown mycelium. Gradually, the needles turn yellow and die. The disease spreads in places where the snow cover slowly melts. The reason for the shute is poor drainage, thickened plantings, the presence of diseased plants on the site;

  

• Browning of needles. This disease of fir, which also causes yellowing of the needles, can affect both young and mature trees. In spring, yellow spots appear on the shoots. Gradually they become brown and spread throughout the tree. In summer, sporulation of the fungus begins. Then on the underside of the needles black dots are formed, arranged in rows;

  

  Advice! To combat needle diseases, preparations containing copper are most effective.
• Spring burn. This disease is not infectious. In the spring, the needles are seriously affected by sunburn. This usually happens in clear weather, when the snow cover has not yet melted. Under the influence of the sun and wind, the needles lose moisture and turn yellow. To avoid burns, in spring the plants are covered with a white non-woven fabric.

  

Before treatment for fungal diseases, all affected shoots are removed. Garden var is applied to the cuts. Branches with signs of disease are recommended to be burned. This will help prevent further spread of the fungus.

For the treatment of conifers, Bordeaux liquid, Oxyhom, Abiga-Peak, Ordan preparations are used. Chemicals are diluted with water at the concentration indicated on the package. When working with solutions, observe precautionary measures: protect the skin and respiratory organs. Spraying is carried out on a cloudy day or in the evening. Re-treatment of plants is performed after 2 – 3 weeks.

Diseases of trunks and branches

If the fir turns yellow and crumbles, diseases of the trunk or shoots can be the cause:

• The death of shoots. Fungal disease affecting Siberian fir species. It appears on annual branches. Gradually, the needles on them dry out, turn yellow, then red. Dark tubercles form on the shoots. In the affected tree, the top remains green, while the shoots thin out in the lower part;

  

• Rust cancer. The causative agents of the disease are fungal spores. With the development of the lesion, vertical shoots appear on the branches. They are also called “witch brooms”. The needles on the branches thicken, in addition, tumors form on the trunks. The disease is viral in nature;

  

• Bacterial dropsy. The lesion covers trees of different ages. First, the needles turn yellow, then turn red. Cracks appear on the trunks, from which a black liquid protrudes. The wood has a sour smell.

  

Diseases of this kind weaken the trees, as a result of which they gradually dry out. Trunks become prone to decay and insect attack. In mass and single plantings, diseases cannot be treated. Affected trees are cut down, and the soil is disinfected.

root diseases

Yellow needles indicate that the tree is not getting enough nutrients. This may be due to diseases of the root system.

Common diseases of fir roots:

• Motley rot. The disease appears in the sound part of the trunk and roots. Gradually, the lesion rises up to a height of 3-4 m. The affected wood has a strong smell of turpentine and releases a lot of resin. Gradually, it becomes reddish-brown, covered with black dots and white spots. At the base of the tree, fruiting bodies of mushrooms are formed;

  

• Fibrous rot. Appearing at the bottom of the trunk, this lesion is light yellow in color with black stripes. The disease rises to a height of up to 8 m. As a result, fruiting bodies up to 15 cm in size appear on the trunk. They are yellow-brown at the top, rusty from the bottom;

  

• White sap rot. With the development of the disease, a fibrous mycelium and dark sinuous formations appear in the wood. The lesion is observed from the base of plants to a height of 3 m. Large growths form at the roots.

  

Fir pests and their control 

Fir is also susceptible to attack by various types of insects. Many of them are also found on other conifers. Pests of fir eat buds, shoots, needles, trunks, root system and cones. As a result, the needles turn yellow, and the tree begins to develop slowly. In addition, many insects are carriers of diseases.

Types of fir pests:

• Needle-eating. These insects feed on buds and needles. This includes moths, leafworms, volnyanka, silkworms. In Siberian forests, silkworm caterpillars cause great damage to coniferous plantations. The needles of affected trees turn yellow, while cobwebs remain on it;
• Sucking. Pests suck out nutrients from the needles, branches and trunk. Aphids, scale insects, hermes can be found on fir. Insects prefer young trees in nurseries and extensive stands. The pests are small and brownish-green in color, so they are difficult to detect visually. The most noticeable are their traces – sticky secretions that are covered with a gray coating. Under the influence of sucking insects, the growth of trees slows down;
  Advice! For the treatment of fir disease in the form of white plaque, it is important to eliminate all sucking pests on the site.
• stem. Pests feed on the bark and root system of conifers. These are bark beetles, goldfish, glass cases, weevils, moths. Often these insects choose dead or weakened trees, in the wood of which they gnaw passages;

  

• Pests of cones. These include leafworm caterpillars, moths, gall midges. Cones affected by insects grow slowly, become covered with resin drops, change shape;
• Root pests. Wireworms and beetles cause the greatest damage to fir. Their larvae eat not only fir crops, but also other types of plants. They gnaw through the roots, which weakens the development of trees. If insects are found, the entire garden is treated. The fight against the larvae of these pests is complicated if the site is located next to the forest.

Single insects are harvested manually or collected using traps. Affected shoots are cut with a knife. Then they start processing fir with special means – insecticides. Fufanon, Decis, Rogor are effective against crop pests.

A solution is prepared for spraying fir. To do this, the required amount of the drug is dissolved in water. Landings are processed every 1 – 2 weeks. The solution is applied with a spray gun on a cloudy day or in the evening. During the season, up to 4 treatments are performed.

A weakened tree requires top dressing, which is a complex fertilizer for conifers containing phosphorus and potassium. Substances can be dissolved in water and watered plants.

Preventive measures

The best way to avoid fir diseases is to follow agricultural practices. Preventive measures for the care of conifers include watering, top dressing, soil moisture control.

The list of works that help protect fir from diseases:

• watering should be normalized, excessive moisture should not be allowed;
• to improve drainage into the ground, drive plastic tubes up to 30 cm long;
• it is necessary to shade the plants in the spring with the help of agrofiber;
• make phosphorus-potassium supplements;
• carry out soil mulching;
• perform pruning, avoiding dense plantings.

To prevent the spread of pests, the following measures should be applied:

• digging the soil in autumn;
• spraying plantings with insecticides in spring and autumn;
• pruning shoots, control over the density of plantings.

Conclusion

Fir diseases spread quickly and can completely destroy trees. Therefore, it is important to identify the symptoms in time and start treating the plant. In addition, yellowing of the needles can be caused by improper care and the spread of pests.