Evergreen cedars, pines, spruces, juniper thickets require minimal maintenance. But they can turn yellow, become covered with a white coating. Over many years of gardening experience, she learned to treat almost all coniferous tree diseases. You can save the decorative appearance of needles if you correctly establish the cause of plant damage.
The main diseases of ornamental conifers
The tips of the needles begin to turn yellow for various reasons. In the spring, from the bright sun, burns occur, bronze appears. Common infections include fungal infections. Rust often appears on a pine tree, juniper is affected. From bloating that occurs on the branches, spores are transferred to currants, pears. Fusarium, cytosporosis, fomosis are considered dangerous diseases. Thuja suffers from them. Defects appear on the bark, branches. The needles are getting dark and falling.
Old, groomed trees are susceptible to disease. There are breeds of conifers that are resistant to fungal diseases. But they are not safe from the attack of caterpillars. There is only one conclusion: they have brought evergreen forest wonders on the site, learn how to deal with infections and pests.
Non-communicable diseases of conifers and measures to eliminate
Burn. Solar radiation is especially dangerous for young trees. The snow cover reflects the rays, enhances the evaporation of moisture. The roots in the frozen earth are not able to compensate for the loss. Sap flow begins when the soil warms up to + 4 ° C, to this temperature the roots are asleep. Young conifers planted in the fall are capable of dying from a burn. My young pine died, we did not shelter for the winter. I noticed that glare from greenhouses, windows of houses, shiny roofs act like mirrors. If brown or yellowish spots appear on the crown, you need to look for where the bright light comes from.
Protection measures against the spring sun:
- Spraying helps young trees - the branches are abundantly moistened from a sprayer or garden sprayer.
- You can throw burlap or covering material on small trees in spring or autumn. It will protect from the scorching sun and the withering wind.
- Spreading black earth or ash on snow, they "start" the process of snow melting, the roots begin to absorb moisture.
When planting trees, it is important to maintain the integrity of the root earthen coma. When seedlings are purchased in pots, they take root better. Pine trees are more resistant to transplantation; their needles grow after rooting. The most capricious is forest spruce. She is usually ill for a long time, it is advisable to shade it in the spring during the first three years. From junipers, I advise varieties "Skyrocket", "Blualps" (Cossack).
Other causes of yellowing of the needles:
- Mechanical tree injuries occur due to snow load, damage to animals.
- The undeveloped root system is characteristic of weakened seedlings, it is better to immediately choose a decent planting material.
- With strong return frosts with active melting of snow, the crust cracks, it must be checked, varnished with cracks.
- In flooded places, stagnant water provokes the development of root rot, changes the acidity of the soil.
Bioactive drugs increase the resistance of conifers to non-infectious lesions:
- Cornevin (stimulates root growth)
- Super humisol - a balanced mixture of trace elements and minerals;
- Zircon - a complex action drug;
- Siliplant is a silicon-containing chelated micronutrient fertilizer.
Timely top dressing well strengthens the immunity of plants, they are less prone to burns, grow faster in spring.
Infectious diseases of conifers: prevention and treatment
Fungal diseases on all cultures are treated approximately the same, with the preventive treatment of fruit and vegetable crops, we necessarily treat the conifers with Bordeaux liquid. If the plant still gets sick, resort to purchased drugs. It is important to establish the cause of the lesion correctly in order to determine which remedy to acquire.
I will start with the winter Schütte disease, the fungus develops under the snow, when about 0 ° C. Symptoms appear in spring or summer. According to the description, the disease is not similar to other fungal infections, appears on needles:
- gray-black plaque;
- small dots.
The needles darkens or turns yellow, falls off.
Control measures:
- sulfur-lime broth - 3 times in the summer;
- with the Abiga-Peak and HOM preparations, two treatments are enough.
Be sure to spill the soil to a depth of 5 cm.
Rust is similar to fruit tree damage. Traditional methods of treatment: fungicides and copper-containing preparations.
Pine trophy is manifested by the curvature of the shoots. Swellings of a yellow-orange color appear. For treatment, you need Fundazol, two treatments are enough.
Fusariosis develops in the soil at the roots of pine, spruce, larch, fir, when it is too damp. The central part of the crown crumbles.
They carry out drainage, the use of "Fitosporin", "Alirina" will help to revive the trees, they will turn green again if the branches do not have time to completely dry out.
Alternariosis is terrible for junipers, thujas growing in the shade. Blackish, dark gray spots spread along the needles. Affected branches are removed. For the treatment of conifers, compounds with copper sulfate or celandine infusion are used. The fungus must be suppressed until late autumn.
Bacteriosis is characterized by blanching of needles, it begins to crumble from a light touch. This disease is not treated. For prevention, treatment is carried out with Fitosporin.
Biorell cancer is dangerous in that it infects wood. When an infection gets, the color of the young bark changes, it becomes brown, then it cracks, dies. Long elongated ulcers form, they are covered with tarry fungal growths.
Gradually, the tree dies, the needles turn yellow, crumble. For treatment, triple treatment is needed at intervals of 2 weeks. It is important to wet the soil well with the preparations.
Pests of conifers prevention and control methods
It is advisable to help the trees in early spring, as soon as the snow melts, during the day the air temperature rises to +6 ° C. If the treatment is carried out in the fall, then you can not get rid of pests and diseases, insects prepare for hibernation, climb into secluded corners. I dilute drugs according to the instructions, I always use protective equipment when working.
Now about the insects that have to be fought, and how to do the processing:
Fir, cedar and ordinary pine, spruce, larch are sometimes infected by rapidly propagating hermes, it is also called pine aphid. The determination of the pest is simplified by the appearance of white plaque.
Sucking insects with transparent wings grow to 2.5 mm, their color is green, dark brown, black and gray. Hermes with small tendrils suck juices from young shoots.
The best remedy for hermes is the universal remedy Pinocide for pests, the dosage of the remedy for different types of insects is indicated in the instructions.
Bark beetles fall from the forest, if the site is far from the forest, there should be no fear of the bark beetle invasion. Beetles lay eggs under the bark, gnaw tunnels for this. Dark larvae reach 15 mm in length, continue the work of their parents, dig new shelters for themselves.
After wintering, larvae and beetles creep out, it's time to poison them. It is recommended to use modern intestinal insecticides.
Sawmills red, ordinary scary pines. Externally, insects resemble bees, only smaller in size. Masonry is done in the bark. Light green caterpillars are poorly distinguishable in young needles. When dried branches appear, they are treated with the following preparations:
- Spark Double Effect (the most effective remedy);
- Golden Spark (recommended for cedar firs);
- Senpai - a universal insecticide;
- Alatar is a complex action drug.
False caterpillars of the green sawfly in our garden did not appear even once, they harm the juniper. These are small caterpillars with contrasting stripes, a brown head. They winter in the recesses of the bark, in the nodes of the branches, under a layer of needles. It is necessary to process all parts of plants, to shed well the soil. It is better to rake the needles completely and to fill in the mulch instead.
False shields prefer juniper, thuja, yew. These are insects with a hard shell. Females have a round shape, males have an elongated shape. Larvae with legs are especially dangerous. They quickly spread over the crown. "Fufanon" or "Iskra-M" acaricides are effective against them.
A spider mite braids the tops instantly, such a picture is often. Microscopic insects are especially active on hot rainy days. I use against the tick Actellic, Fufano, "Karbofos.
Pine silkworms - larvae of motley butterflies with a wingspan of 7-8 cm. Caterpillars appear in early spring, by the end of June you can already see pupae in the middle lane. Larvae gnaw on bark on young shoots, branches dry up. Early treatments with Bordeaux fluid will help preserve conifers.
Evergreen trees also have other misfortunes, but they are characteristic of warmer regions of growth.
