Juniper diseases

Juniper is a popular crop in landscape design, widely used for decorating household plots and in urban landscaping. There are more than a hundred species and varieties of this evergreen plant – trees of various shapes and sizes, medium-sized, dwarf and creeping shrubs. Junipers go well with deciduous trees, flower beds, they can be used to create various compositions. Undemanding to the care and composition of the soil, they can be affected by pathogenic microflora and parasites. How to identify plant diseases and harmful insects, what drugs to treat the plant for treatment and prevention will be described later.

Juniper diseases and their treatment

Juniper is rarely damaged by diseases and pests. This is a strong plant that is not afraid of adverse climatic conditions. Most of all, juniper is susceptible to infection by diseases and pests in the spring, until warm weather is established. At this time, juniper is harmed by sudden changes in temperature, which causes frostbite of the roots or burns and drying out of the crown. The culture hardly tolerates stagnant moisture in the roots, which is formed after the snow melts, or, on the contrary, a long drought after a snowless winter. As a result, the immunity of juniper weakens, it becomes defenseless against various pathogens. Immature young plants are also susceptible to infection. Visually diagnosing juniper diseases is very difficult, common symptoms for them are yellowing, browning and dying off of needles, drying out of branches, thinning of the crown. Next, an overview of the most common juniper diseases with photos and recommendations for their treatment will be presented.

Rust

Juniper rust disease is caused by the fungus Gymnosporangium, which requires two host plants for a complete life cycle. Juniper is a winter host, rosaceae (apple, pear, quince) are summer hosts. The fungus lives on branches, trunk, needles and cones, causing the branches to die off, drying out and cracking the bark. The disease manifests itself in spring: brown formations form in the wounds of the plant, which, after rain or dew, swell and become covered with mucus. Spores germinate from them, forming an orange coating. The wind carries them to fruit trees. They parasitize on leaves, form outgrowths, on which spores ripen, subsequently affecting the juniper. Infection occurs within a radius of 6 km.

In order to control the disease, you should:

• cut off infected branches in early spring and winter;
• do not plant both host plants side by side;
• treat juniper from rust with a solution of “Arceride”, Bordeaux liquid.

Favorable conditions for the spread of the disease are dampness and coolness. During the period of prolonged rains, the juniper should be regularly inspected. Having found orange growths on the above-ground parts of the plant, you need to hurry to process it.

Juniper rust disease is shown in the photo:

Necrosis is dry

This juniper disease is also called nectriosis or nectrium cancer. The causative agent, the fungus Netctriacucurbitula, penetrates into a wound on a tree resulting from mechanical damage to the bark. The disease is manifested by the formation of local and ring necrosis of branches and trunks without color change. In spring, brick-red convex smooth pads up to 2 mm in diameter appear in the cracks in the bark. These are stromas – plexuses of mycelium, on the surface of which spores develop. Over time, they turn black and dry out. Subsequently, the needles begin to turn yellow, the bark is rejected, the branch dies off, the juniper dies. To prevent the development of the disease on the plant, you need to take measures:

• remove diseased branches;
• thin out thickened plantings;
• treat with a copper-containing preparation.

When destroying a plant, it is important to thoroughly clean the soil of plant debris and treat it with the Quadris, Tilt fungicide – this will prevent re-infection with the disease.

Biotorell cancer

The disease occurs in the same way as nectriosis – the spores of the fungus Biatorelladifformis settle in the damaged bark and juniper wood. The penetration of infection is facilitated by the activity of insects that destroy the integrity of the cortex. The disease spreads rapidly, causing necrosis of the cortex: its browning, drying out, cracking. In the future, the wood gradually dies off, longitudinal oval wounds form in it. Ulcers – deep, stepped, with torn edges, more concentrated in the middle part of the branches and trunk, more often on the north side. The disease affects junipers growing in unfavorable conditions, greatly weakens them, leading to drying out of the culture, and a decrease in resistance to snowfall. For treatment you should:

• cut out the affected parts of the plant;
• treat the juniper with an antifungal drug, paying special attention to the places of cuts.

Alternaria

If the branches and needles of the juniper turn brown, covered with a black coating, this indicates an infection with the Alternariatenus Nees fungus. In the future, the needles crumble, the branches die off. To combat the disease, juniper must be treated with HOM or Abiga-Peak preparations, Bordeaux mixture. Affected branches must be removed by lubricating the cut points with garden pitch or oil paint on drying oil.

Fuzarioz

This juniper disease is also called tracheomycosis wilt. It affects plants of any age. The causative agents are anamorphic fungi of the genus Fusarium that live in the soil. They penetrate first into the roots of the juniper, causing their partial decay, then into the vascular system, preventing the movement of juices. By the time the disease appears in the aerial part, the plant will already be affected by the disease to a large extent. The presence of whitish or reddish spores of the fungus in the area of ​​​​the root collar and a dark ring on the cut of the branch will help to identify the hidden disease of the juniper.

At the first symptoms, the soil should be treated with solutions of Fitosporin-M, Agat-25K, Gamair, Fundazol, Alirin-B biopreparations. You can try to save the juniper from the disease by cutting out the affected branches and treating the cuts with copper sulphate.

Schutte

Schutte is a group of diseases affecting conifers. It is manifested by redness, drying out and dying off of the needles. The reason is pathogenic fungi of various genera. There are 2 types of schütte on juniper.

Brown

The causative agent of the disease is the fungus Herhpotrichianigra. Infection occurs in autumn, development occurs in winter under snow cover at a temperature not lower than + 0,5 ˚С. The disease appears in the spring, in March-April. After the snow has melted, yellowed needles are visible on the branches, covered with a snow-gray coating resembling a cobweb. Over time, it darkens, becomes black-brown, dense, “glues” the needles. The needles turn brown, but do not crumble, held together by mycelium. In autumn, rounded spores appear on them.

Shutte juniper

The disease is caused by the fungus Lophodermium macrosporum. Symptoms: in the spring, the needles of the previous year acquire a yellow-brown color and do not crumble for a long time. By the end of summer, it is overgrown with mushrooms up to 1,5 mm in diameter.

For the treatment of both types of shutte, the same measures must be taken:

• cut out diseased parts of the plant;
• treat with fungicides “Strobi”, “Skor”, “Ridomilgold”, colloidal sulfur.

Juniper pests and their control

Juniper pests attack to a lesser extent than other conifers, there are not many insect species that have adapted to the specifics of feeding on it. However, their vital activity can lead to a loss of decorativeness and death of the plant. Parasites that harm juniper are divided into sucking and needle-eating. It is important to identify the infection at an early stage, treat the plant in a timely manner in order to prevent insects from multiplying and causing severe harm.

juniper sawfly

The adult sawfly has a green color, the head is brown-green. Larvae, caterpillars, green, with stripes on the body. They eat needles and young shoots. Lives in the ground, in the trunk circle. Insect control consists in digging the soil in the root zone, destroying larvae and nests manually, using adhesive belts. For the best result, the plant must be treated with Bi-58, Kinmiks insecticides.

Juniper scale insect

Lives in needles and cones. The larvae are light yellow in color, up to 1,5 cm in size, suck juices from the bark. This leads to its death, infection with fungal spores, a decrease in immunity and a slowdown in the growth of juniper. In the fight against them, a 0,2% solution of “Karbofos” is effective. If last year there were already problems with the shield, in the spring the juniper must be processed for preventive purposes.

spruce spider mite

Its presence is indicated by a web that densely entangles the branches of the juniper, yellow spots on the needles, and its shedding. The insect breeds very quickly: it reproduces up to 4 generations per season. During the growing season, it can destroy the plant, especially young seedlings. To destroy the spider mite, it is recommended to treat the culture with acaricides “Sumiton”, “Aktellik”, “Karate”.

Pine moth

The moth is a lepidopterous butterfly that destroys juniper needles in the summer-autumn period. The wings of males are dark brown, those of females are red-brown with whitish or yellowish spots. Caterpillars are green at first with a yellow head, later becoming blue-green or yellow-green with 3 longitudinal white stripes. It multiplies intensively in hot dry summers and warm autumns. In October, the larvae descend into the litter, where they pupate and overwinter. Infection is diagnosed by inspection: corrugated grooves and notches appear on the needles.

In the fight against larvae, larvicides are effective: Methyl-Nirophos, Baitex, Arsmal, Parisian Greens. To treat plants against moths, you should use the funds only in overalls and using respiratory protection. Early autumn frosts can completely destroy their population on the juniper.

gall midges

Gall midges are small mosquitoes up to 2,2 mm in length. As a result of the bites of the larvae (yellow-orange in color), cone-shaped galls appear, consisting of 3-4 whorls of needles. Galls are used by insects for food and shelter from entomophagous predators. As the larvae grow, the tops of the needles bend outwards. Treatment: treat with Fufanon, Actellik, Commander, Iskra, Intavir.

Ants

Ants are equally beneficial and harmful. They loosen and structure the soil, eat the larvae of harmful insects, enrich the soil with organic matter and humus. The significant harm that comes from them is the cultivation of aphids on the aerial parts of the juniper and in the roots. The plant receives damage, due to which its development and growth slows down. The activity of ants can lead to the death of juniper. Ants are also harmful in that they carry diseases from plant to plant. To get rid of insects, it is necessary to detect an anthill, treat it with Aktellik, Fufanon preparations.

aphid

Small wingless brown insect with two longitudinal stripes on the back. It feeds on juniper juice, weakening it. Young shoots and seedlings are especially affected. The fight against aphids begins with the destruction of ant nests. For best results, juniper should be treated with poisonous compounds:

• anabazine sulfate solution (20 g per bucket of water);
• “Rogor”;
• Mospilan;
• “Decis”;
• “Confidor;
• “Calypso”.

Also against aphids, juniper can be treated with soapy water (250 g per 5 liters of water). When processing the crown, you need to ensure that the composition does not fall into the root zone.

Preventive measures

The disease is easier to prevent than to treat. Preventive measures taken in a timely and regular manner can ensure the health of the juniper and protect it from diseases and pests. The basis of juniper care is:

• Compliance with the rules of agricultural technology – site selection, soil composition, mulching, loosening, top dressing.
• Timely application of fertilizers and immunomodulators. Super-humisol, Epin-extra, Siliplant, Nikfan have proven themselves well as root and foliar dressings.
• Regular sterilization of garden tools, soil, seedling containers.
• Liming of acidified soils. Excessive acidity of the soil contributes to the occurrence of fungal and viral diseases.
• Complete nutrition of juniper, which forms immunity, sufficient intake of potassium, phosphorus, nitrogen.
• Use of healthy planting material, carrying out activities for the quarantine of new plants.
• Destruction of harmful insects – carriers of diseases.
• Soaking the roots before planting in “Fitosporin”, “Vitaros”, “Maxim”.

Favorable conditions for the development of diseases are dense plantings, excessive shading, high humidity, soil acidity. When choosing a place for planting juniper, you need to choose lit and ventilated areas with light, well-drained soil. For the prevention of diseases, the plant should be treated twice a year with solutions with a high content of copper, colloidal sulfur, and systemic fungicides. Removed branches, bark and needles that fall during illness must be burned.

Conclusion

Juniper diseases occur as a result of the plant being in adverse conditions, which initially worsen its development. In this case, the gardener needs to pay increased attention to the culture – to provide adequate nutrition, loosen the soil, remove weeds, inspect for the appearance of parasites and pathogenic microflora, and attract beneficial insects to the site. Then the juniper will be a real decoration of the garden for many years.