Tracheomycotic wilting (fusarium) of juniper
The causative agents of the disease are fungi Fusarium oxysporum and F. sambucinum - cause decay of the root system. The mycelium penetrates into the vascular system and fills it, the roots turn brown. Access is terminated nutrients into the crown, starting from the upper shoots, the needles turn yellow, redden and fall off, and the plants themselves gradually dry out. Young plants are most affected. Since the fungi spread through the vessels, the disease at first can proceed in a latent form. On the affected parts of plants, especially on the roots, when high humidity a grayish-white sporulation of the fungus appears.
The infection persists in plants, in diseased plant debris, and often spreads with infected planting material or infected soil.
The disease is common in low areas with stagnant water, and in low light plants.
Control measures. Timely culling and destruction of all dried plants along with roots, destruction of affected plant residues. Compliance with agricultural techniques. For prevention, before planting, young plants with an open root system are etched in a solution of one of the drugs: Baktofit, Vitaros, Maxim... At the first symptoms of wilting and root rot, spill the soil under the plants with a solution of one of the drugs: Fitosporin-M, Alirin-B, Gamair... Carry out preventive and eradicating spraying and soil shedding with a 0.2% solution Fundazola.
Juniper rust
Fungal spores germinate on shoots, skeletal branches, needles and cones and form a wintering mycelium. Fusiform thickenings appear on the affected parts, and individual skeletal branches die off. On the trunks, more often at the root collar, swellings and sagging are formed, on which the bark dries out, and shallow wounds open. In early spring, when there is still snow all around, brown outgrowths (up to 0.5 cm) appear on the branches, trunks, in the cracks of the bark, which swell after rain and become covered with mucus (up to 1.5 cm). Spores develop in them, which germinate and form a golden-orange bloom. They are quickly carried by the wind and infect rosaceous crops.
In spring, on rosaceous plants, yellowish-brown spots with black dots are formed on the upper side of the leaves, and on the lower side there are galls, large protrusions, seated with long, horn-like outgrowths. On the surface of the galls, spores mature, then infecting the juniper.
Over time, the affected juniper branches dry out, the needles turn brown and crumble. The infection persists in the affected juniper bark. The disease is chronic, practically incurable.
Control measures. In addition, you should place junipers away from rosaceous plants or create a barrier between them of other types of plants. As a last resort, remove the less valuable intermediate disease host.
Shrinking juniper branches
Several fungi can be causative agents: Cytospora pini, Diplodia juniperi, Hendersonia notha, Phoma juniperi, Phomopsis juniperovora, Rhabdospora sabinae... The bark dries up, numerous small brown and black fruit bodies are formed on it. The needles turn yellow and fall off, the branches of the bushes dry out. The infection persists in the bark of the affected branches and in unharvested plant debris. Thickened plantings contribute to its spread.
Control measures. Compliance with agricultural techniques, the use of high-quality planting material. Pruning of affected branches, disinfection of individual wounds and all sections with 1% solution and covering oil paint on natural drying oil, garden stew or pastes ( Runnet). Collect and burn all cut off affected branches. Carrying out preventive spraying of plants in spring and autumn with 1% Bordeaux mixture or its substitutes ( Abiga Peak, HOM). When the disease manifests itself to a strong degree in the summer, they are sprayed again with them.
Juniper Alternaria
The causative agent is a mushroom Alternaria tenuis... A black velvety bloom appears on the affected brown needles and branches. The needles fall off, the branches dry up. The disease manifests itself when plantings are thickened on the branches of the lower tier. The infection persists in the affected needles and bark of branches and in plant debris.
Control measures. As if the branches of a juniper are drying out.
Brown juniper shute (brown coniferous snow mold)
Pathogens - fungi Herpotrichia juniperi and H. nigra... The disease develops under snow at temperatures not lower than +0.5 ° C. In spring, branches of junipers freed from snow are covered with yellow or brown needles. It is entangled with cobweb mycelium, which is grayish at first, but gradually becomes black-brown, dense and, as it were, gluing needles. Over time, black spherical small fruiting bodies of the wintering stage of the pathogen fungus form in the affected needles. The needles turn brown, dry out and do not crumble for a long time. This greatly reduces the decorative effect of plants. Thin branches die off. The infection persists in the affected plant debris and in the affected needles.
The development of the disease is facilitated by high humidity, thickening of plants. Young plants are most susceptible to damage.
Control measures. Timely pruning of dead branches, preventive spraying of plants in spring and autumn with 1% bordeaux mixture or its substitutes ( Abiga Peak, HOM). When the disease manifests itself to a strong degree in the summer, spraying is repeated with one of the same drugs.
Shute juniper
The causative agent is a mushroom Lophodermium juniperinum... The needles of last year's shoots turn brown in May or turn dirty yellow and do not crumble for a long time. Since the end of summer, small round shiny black fruit bodies up to 1.5 mm in diameter are formed on the needles. The infection persists in the affected needles and plant debris. The disease develops intensively on weakened plants in humid conditions.
Control measures. As with the brown juniper shute.
Biotorella Juniper Cancer
The causative agent is a mushroom Biatorella difformis... With mechanical damage to the branches over time, this fungus causes bark necrosis. The fungus spreads in the tissues of the bark, it turns brown, dries up, and cracks. The wood gradually dies off, longitudinal ulcers are formed. Rounded fruiting bodies are formed over time. The defeat and dying off of the bark leads to the fact that the needles turn yellow and dry out. The infection persists in the bark of the affected branches.
Control measures. As if the branches of a juniper are drying out.
Juniper bark nectriosis
The causative agent is a mushroom Nectria cucurbitula... On the surface of the affected bark, numerous brick-red sporulation pads with a diameter of up to 2 mm are formed, over time they darken and dry out. The development of the fungus causes the death of the bark and bast of individual branches. The needles turn yellow and fall off, affected branches and whole bushes dry up.
The infection persists in the bark of affected branches and plant debris. Thickened plantings contribute to its spread.
Control measures. As if the branches of a juniper are drying out.
Before the first use, any drug must be tested on one plant. If the condition of the plant has not worsened during the day, the drug can be used on all protected plants of this species. It is recommended to alternate preparations for greater effectiveness.
Be careful when using plant protection products. Always read the label instructions and product information before use. Carry out processing in compliance with all safety rules.
Why does juniper turn yellow
With a competent transplant and proper care behind the plant, the juniper needles begin to turn yellow and fall off. Why is this happening? This phenomenon can be explained by several reasons.
The first reason is the biological feature of the plant. Every four years in the fall, the old needles inside the crown of the juniper begin to turn yellow and fall off, and a new one grows in its place. This is the process of renewing the needles of a plant.
The second reason is technocratic. Juniper grows only in ecologically healthy areas. If the personal plot is located near highways or industrial enterprises, the plant is likely to die.
In addition, acid rain, falling with alarming frequency, causes the death of conifers and some deciduous trees.
A few words to explain this phenomenon. In the industry of Europe, most of Germany, brown coal is actively used. The sulfur contained in brown coal, being oxidized, turns into sulfuric anhydride, which, together with the smoke, enters the atmosphere, where it reacts with water droplets. This is how sulfuric acid is formed. Together with air masses it spreads over thousands of kilometers and falls together with precipitation on the ground. I must say that in Germany, it is for this reason that they stopped planting conifers.
About one of the ways of pelleting carrot seeds \u003e\u003e
Diseases of juniper - drying out of branches, brown needles, rust, yellowing of needles and others
Consider the most common juniper diseases in Russia, in addition, we list the main pests of this coniferous plant.
Tracheomycotic wilting, or fusarium, juniper
The causative agents are fungi Fusarium oxysporum Schl. and F. sambucinum Fuck., are soil pathogens that cause rotting of the root system. The roots turn brown, the mycelium penetrates into the vascular system and fills it with its biomass. The access of nutrients stops, and the affected plants, starting from the upper shoots, wither, the needles turn yellow, turn red and fall off, and the plants themselves gradually dry out. Seedlings and young plants in nurseries are most affected. It is believed that with the age of plants, the fungus passes into the composition of mycorrhiza and does not cause much harm.
Figure: 69. Reddening of the needles and drying out of a young plant
COMBAT MEASURES
Use healthy planting material. Timely culling and burning of all dried plants along with roots, collection of affected plant residues. Compliance with all agrotechnical requirements for growing this crop. For prophylactic purposes, green cuttings are etched before rooting and young plants with an open root system before planting in a solution of one of the drugs: bactofit, vitaros, maxim. At the first symptoms of wilting and root rot, the soil is shed under the plants with a solution of one of the drugs: phytosporin-M, alirin-B, gamair. In industrial cultivation, prophylactic and eradicating spraying and soil spilling with a 0.2% solution of foundationol are carried out.
Shute brown juniper
Figure: 70. The beginning of the manifestation of shute.
Figure: 71. Drying of the bush with a strong spread of brown shute.
The causative agent is the mushroom Herpotrichia juniperi. In spring, the needles turn yellow and become covered with a cobweb mycelium, which is grayish at first, but gradually becomes black-brown, dense, as if gluing the needles. Over time, black spherical small fruiting bodies of the wintering stage of the pathogen fungus form in the affected needles. The needles turn brown, dry up and do not crumble for a long time, which
greatly reduces the decorative effect of plants. The infection persists in the affected plant debris and in the affected needles.
COMBAT MEASURES *
Use of healthy planting material, timely pruning of dead branches, preventive spraying of plants in spring and autumn with 1% Bordeaux mixture or its substitutes (ABIGA-PIK, HOM). With the manifestation of the disease to a strong degree in summer time spraying is repeated with one of the same preparations.
Shute juniper
Figure: 72. Yellowing and drying of the needles are the first signs of shute.
Figure: 73. Formation of fruiting bodies on dried needles inside the crown of a plant.
The causative agent is the mushroom Lophodermium juniperinum. The needles of last year's shoots in the spring, in May, turn brown and do not crumble for a long time. Over time, small shiny black fruit bodies are formed on the needles. The infection persists in the affected needles and plant debris.
COMBAT MEASURES
The same as against the brown juniper shute.
Shrinking juniper branches
Figure: 74. Desiccation of lateral branches during the manifestation of the disease.
Figure: 75. Formation of fruiting bodies during the spread of drying out of branches.
Figure: 76. Dying off of the bark and lateral branches.
Several fungi can be the causative agents of branch drying: Cytospora pini Desm., Diplodiajuniperi West., Hendersonia notha Sacc. et Bn, Phoma juniperi (Desm.) Sacc, Phomopsis juniperovora Hahn., Rhabdospora sabinae Sacc. et Fautr. Drying of the bark and the formation of numerous small fruit bodies of brown and black color are observed on it. The needles turn yellow and fall off, the branches of the bushes dry out. The infection persists in the bark of the affected branches and in unharvested plant debris. The spread of infection is facilitated by thickened planting of plants and the use of contaminated planting material.
COMBAT MEASURES
Compliance with all the requirements of agricultural technology, the use of high-quality planting material. Pruning of affected branches, disinfection of individual wounds and all sections with a 1% solution of copper sulfate and smearing with oil paint on natural drying oil. Collect and burn all cut off affected branches. Carrying out preventive spraying of plants in spring and autumn with 1% Bordeaux mixture or its substitutes (ABIGA-PIK, HOM). When the disease manifests itself to a strong degree in the summer, spraying is repeated with the same preparations.
Juniper Alternaria
Figure: 77. Browning and drying of needles and branches affected by alternarias.
Figure: 78. Browning and dying off of the branches of a young plant affected by alternariasis.
The causative agent is the fungus Alternaria tenuis Nees. A velvety bloom of black appears on the affected brown needles and branches. The needles fall off, the branches of the bushes dry up. The disease manifests itself when plantings are thickened on the branches of the lower tier. The infection persists in the affected needles and bark of branches and in plant debris under the bushes.
COMBAT MEASURES
Juniper rust
Figure: 79. Juniper branches with a strong spread of rust.
Figure: 80. The appearance of mucus on a swollen branch of a juniper.
Figure: 81. Formation of mucus on the affected juniper needles.
Figure: 82. Sporulation of rust on the affected branches.
Figure: 83. Browning and drying out of bushes with strong spread of rust.
The causative agents are fungi Gymnosporangium confusum Plown, G. juniperinum Mart., G. sabinae (Dicks.) Wint. Mushrooms are of various households: the main cycle of their development occurs on the juniper, and the intermediate hosts are seed crops (apple, pear, quince, hawthorn, cotoneaster).
Fungal spores germinate on shoots, skeletal branches, needles and cones and form a wintering mycelium. Thickening appears on the affected parts, and the death of individual skeletal branches begins. On the trunks, more often at the root collar, swellings and sagging are formed, on which the bark dries out and shallow wounds open. In early spring, when there is still snow all around, brown outgrowths appear on the branches, trunks, in the cracks of the bark, which swell after the rain and become covered with mucus. They develop teliospores, which germinate and form a golden-orange bloom, consisting of basidiospores. They are quickly carried by the wind and re-inoculate pome crops. Over time, the affected branches dry out, the needles turn brown and crumble. The infection persists in the affected juniper bark. On common juniper, mushrooms that cause rust of apple and quince overwinter, on Cossack junipers, tall and red, a mushroom that causes pear rust (G. confusum Plowr.) Overwinters.
COMBAT MEASURES
The same as against the drying out of juniper branches.
Biotorella Juniper Cancer
Figure: 84. Shrinkage of branches during the manifestation of biotorella cancer.
Figure: 85. Drying of branches, dying off and cracking of the bark, exposure of a cancerous ulcer in the wood.
Figure: 86. Browning and decay of the wood of the trunk of a juniper affected by biotorella cancer.
The causative agent, the fungus Biatorella diformis, is the conidial stage of the fungus Biatoridina pinastri. With mechanical damage to the branches, over time, the bark and wood begin to develop pathogenic microorganismscausing necrosis of the cortex. The fungus spreads in the tissues of the bark, the bark turns brown, dries up, and cracks. The wood gradually dies off, and longitudinal ulcers form. Rounded fruiting bodies are formed over time. The defeat and dying off of the bark leads to the fact that the needles turn yellow and dry out. The infection persists in the bark of the affected branches.
COMBAT MEASURES
Compliance with all the requirements of agricultural technology, the use of high-quality planting material. Pruning of affected branches, disinfection of individual wounds and all sections with a 1% solution of copper sulfate and smearing with oil paint on natural drying oil. Collect and burn all cut off affected branches. In spring and autumn, prophylactic spraying of plants with 1% Bordeaux mixture or its substitutes (ABIGA-PIK, HOM) is carried out. When the disease manifests itself to a strong degree in the summer, spraying is repeated with the same preparations.
Juniper bark nectriosis
Figure: 87. Fruit bodies on juniper bark.
The causative agent is the fungus Nectria cucurbitula, the conidial stage of the fungus is Zythia cucurbitula. On the surface of the affected bark, numerous brick-red sporulation pads with a diameter of up to 2 mm are formed; over time, they darken and dry out. The development of the fungus causes the death of the bark and bast of individual branches. The needles turn yellow and fall off, affected branches and whole bushes dry up. The disease is considered cancerous.
The infection persists in the bark of affected branches and plant debris. The spread of infection is facilitated by thickened planting of plants and the use of contaminated planting material.
COMBAT MEASURES
The same as against the drying out of juniper branches.
We have listed the main diseases of juniper (with names and in pictures), followed by material about the pests of this ornamental culture.
Angle-winged pine moth
Figure: 88. Butterfly on a juniper branch
Figure: 89. Pupa skin after moth butterfly emerges
Angle-winged pine moth (Semiothisa liturata) is a purple-gray butterfly with a wingspan of 25-33 mm. On the outer edge of the front wings it has a slight notch, for which it received the name Anglewing. Front fenders with three, hind wings with two winding lines and dark spot at the top, near which there is a yellow-brown stripe. The hindwings are lighter in color, with a dark dot near the middle and with a dark transverse band along the outer margin. Yasha from green, reddish-brown to purple-gray. Caterpillars up to 30 mm long, green, with a red-brown head and dark green longitudinal stripes. The abdominal legs have alternating, short and long, two-tiered hooks. The pupa is brown, up to 11 mm long. Pupae overwinter in forest litter or in soil; in spring from late May - early June, butterflies begin to fly. Caterpillars feed and develop in the second half of summer and autumn and, after finishing feeding, go into the soil, where they pupate, and then hibernate. The moth is widespread and damages pine, spruce, fir, juniper.
Juniper needles are also damaged by caterpillars of fat cypress (Pachypasa opus Drury.), Juniper sawfly (Monoctenus juniperi L);
COMBAT MEASURES
Carrying out preventive spraying of plants annually, in May - June, with one of the drugs: actellik, decis Profi, fufanon. When a large number of pests are detected in the summer, carrying out eradication spraying with one of the same drugs. In case of severe damage to the branches and their drying out by pests, pruning of dried branches is carried out with the obligatory covering of cuts and cuts with oil paint on natural drying oil.
Juniper Scale
Figure: 90. Shields on a juniper branch
Juniper scutellum Insulaspis juniperi - small sucking insect, female scutellum elongated, brown color, 2 mm in size. Females hibernate; from mid-May they lay eggs under the shield. Fertility of one female is up to 38 eggs. In the middle of the first ten days of June, larvae hatch and stick to the needles. The pest feeds on the needles and cones of juniper,
paris, pine, thuja. With a large number of scale insects, the damaged needles turn brown, dry out and fall off, often drying out of young shoots and branches is observed. At the same time, decorativeness is greatly lost, and young plants even die. The pest develops in one generation.
On needles and cones, there are often thuja scale insects - Carulaspis caruelii (Targ.) And European juniper scale insects - C. viscid Schn, and on needles and twigs, the juniper scale insect - Planococcus vovae (Nass.) Can also feed. Often found on junipers and aphids - Cinara juniperi, which gives 3-4 generations per season. The presence of aphids can be detected by the activity of ants protecting it from other predatory insects.
COMBAT MEASURES
Gall midges
Figure: 91. An adult gall midge insect on a juniper branch.
Figure: 92. Small orange larva emerging from the gall.
Figure: 93. Galls at the base of the needles and outlet openings after the emergence of fusiform juniper gall midge.
Gall midges are small mosquitoes up to 2.2 mm long, have delicate transparent wings and yellowish-brown legs. The body is narrow, the antennae are filiform, the head is small with faceted eyes. The larvae are fusiform, 3-4 mm long, bright orange in color, live and feed in plant tissues, causing them to grow abnormally (galls). Juniper galls can consist of 2, 3 and 4 whorls of needles. In shape, they are conical, fusiform, pointed or oblong. The location, shape and composition of the galls determine specific pests. Thus, galls from whorls of needles on shoots form Valerie's gall midge (Rhopalomyia valerii Tav.), Fusiform juniper gall midge (Obligotropus panteli Kiefif.), Apical juniper gall midge (Obligotropus. Sp.) And common juniper gall midge L.
COMBAT MEASURES
The same as against the angle-winged pine moth.
Juniper stem pests
Figure: 94. Holes in the bark of the juniper stem.
Figure: 95. Holes in the bark of the lateral branch.
Juniper branches and trunks damage several pests. If there are small round holes on the surface of the bark, and a complex system of grooved passages is visible under the bark, then it can be a juniper bark beetle (Phloeosinus bicolor Brulle.) Or a juniper bark beetle (Ph. Turkestani-cus Sem.). If the passages under the bark do not form complex system, then, perhaps, this is a juniper beetle (Anthaxia sepulchralis E), and if there are passages in the bark and in the wood and there is a large larva with pectoral legs, then this is a juniper barbel (Semanotus russicus persicus Sols.).
COMBAT MEASURES
The same as against the angle-winged pine moth. In addition, if holes are found in the bark of trees, injections are carried out with Actellik (without dilution): 1 ampoule / 1 m2 of trunk bark - with drops into each hole.
Ants
Figure: 96. A family of red ants brought into the garden together with planting material
Ants are small insects with a stalked abdomen and gnawing oral apparatus... Males and females have two pairs of membranous wings, which disappear after mating; working ants have no wings at all. Many species of ants play the role of orderlies of the forest, as they feed on dead insects, while others - entomophages - eat sawfly larvae. Some species harm agricultural plants and ornamental gardens, including conifers. In gardens, they are constant companions of sucking pests - aphids, suckers, worms, scale insects, whose sweet secretions feed on and whose colonies are protected from being eaten by other predatory insects. Ants climb into bee hives, cars, people's houses, where they start new families, eat sweet and meat products. Ants and even entire families of ants often enter gardens with imported planting material from
volume books. They live in plant roots, stumps, rotting wood, tree hollows.
COMBAT MEASURES
Places where ants accumulate are watered with solutions of actellik, fufanon, in places where there is no plant, they are poured with boiling water, parsley is planted near the hives, the smell of which scares off ants. During the growing season of plants, diazinon-based preparations are introduced into the places of accumulation: thunder, thunder-2, medvetox, ant, anteater.
Snails
Figure: 97. Stone Helitsigon on a juniper branch.
Snails are gastropods with a spirally wound shell. The skin has a special fold (mantle) lining the shell from the inside. Two pairs of long tentacles protrude on the head - the lower ones form labial tentacles, the upper ones end with eyes. Wide bottom part the body is a leg, with the help of which the mollusks move, leaving a characteristic slimy trail. Females lay eggs in heaps in the ground, hatching larvae are similar to adult mollusks, only smaller. They live in humid shaded places, in thickened plantings, hiding in weeds. They feed on leaves, green shoots, fruits, in years with an abundance of precipitation, they cause significant harm to almost all plants, including conifers. Two generations of the pest develop in a year. There are several dozen species in the gardens, differing in the size and shape of the swirling shell. The largest of them is grape snail (Helix pomatia), the diameter of which can reach 5 cm. Common amber (Succinea putris L.), stone helicigona (Helicigona lapicida L.), thick ifigena (Iphigeniaventricosa Drap.), Etc. are found more often than others.
COMBAT MEASURES
Collection and destruction of single individuals, drainage of wetlands, removal of weeds, thinning of thickened plantings.
European mole
Figure: 98. Moles - heaps of soil thrown out of the hole of a mole.
The European mole (Talpa europaea L.) from the mole family belongs to the order of insectivores. Moles live underground and make shallow and deep passages. Surface passages are noticeable as rolling bulges with soil crumbling on the surface, deep ones are found in the characteristic heaps of earth thrown out of the hole - mole holes. The mole breeds once a year and gives an average of 5 cubs. Although moles feed on earthworms and insects that live in the soil, with a large number they cause serious harm to plants, since, making their passages in the soil, they damage the roots of plants.
COMBAT MEASURES
To scare away moles, it is recommended to fill the passages with a mixture of kerosene and water (1: 200) or put a rag soaked in kerosene into the hole. Of the repellents, the drug crotomet is used at the rate of 10-14 g per hole. Method of application: make a vertical cut in the burrow between two earth emissions. Put 5-7 g (1-2 tablespoons) of the preparation in both ends of the hole. Close the cutout with a board and cover with earth. After 2-3 days, check for the presence of the drug in the burrow. In the event that the preparation is covered with earth, the hole is cut in another place and the operation is repeated. Processing as needed.
When publishing the article "Diseases of juniper and their treatment", materials from the book were used: Treyvas L. Yu. "Atlas key. Diseases and pests of conifers ”.
What to do when junipers turn yellow
What to do when junipers turn yellow?
Junipers turned yellow: what to do? This question worries many connoisseurs of evergreen shrubs. Is it possible to increase the effectiveness of ongoing health improvement activities? What do the experts advise?
- to eliminate fungi, use fungicides, insects and their larvae - insecticides, ticks - acaricides; process the bushes several times until complete recovery with an interval of 2 weeks; in windy weather, spraying should not be carried out; the optimal time for disinfection is morning or evening of a warm day; for fungal diseases, cut branches are treated with copper sulfate and covered with oil paint on drying oil; the following cocktail has proven itself perfectly: Epin (1 ampoule) + Zircon (1 ampoule) + 5 liters of water. This mixture is abundantly sprayed with yellowed needles. It can be done several times at intervals of several days.
If the needles fall only on inside crown and only at the beginning of autumn, then, most likely, nothing terrible happens. This is a natural process of changing the "fur coat", which lasts 2-3 years. After the old needles fall off, you will see a new one - young and beautiful under it.
But if the needles fall out throughout the crown, then perhaps the reason lies in the excessive gas pollution of the atmosphere. Yellowing can also be caused by acid rain. IN recent timesunfortunately this often happens.
In any case, don't expect instant results. The needles take a long time to recover. Sometimes it takes 2-3 years.
Other causes of yellowing of juniper
Not only fungi and pests contribute to the yellowing of needles. In order for the juniper to please the eye, it is important to arm yourself with the knowledge of proper planting and cultivation.
One of the most common causes of yellowing of needles is drying out of the roots. When planting, put a few small stones on the bottom of the hole, cover them with earth (mix it with peat, sand and clay) and only then start planting juniper. Do not completely cover the root collar with soil. Do not plant shrubs in the open sun - junipers like partial shade. Avoid strong waterlogging and soil compaction. In spring and autumn, spray with such bioregulators of growth as "Zircon", "Elin", "Elin-extra".
Juniper is a beautiful but difficult plant to care for. Quite often, the needles begin to dry and fall off without visible circumstances. So what to do if junipers turn yellow? How to deal with this?
Junipers are considered an unpretentious decoration of garden and summer cottages. But in fact, the opposite happens. Evergreen shrub brings a lot of trouble to the owner. And the most important is the yellowing of the needles. In this article, we will look at why junipers turn yellow and how to deal with it.
Juniper turned yellow: circumstances
The circumstances of juniper yellowing may be a couple.
Circumstance # 1. Diseases
One of the most common diseases is shute... It manifests itself in the form of transformation of the color of the needles, their withering away and loss. The causative agent is a fungus that affects mainly not strong plants growing in the shade or on overly wet soils. It is possible to identify the problem in June. Just at this time, ellipsoidal or rounded black spores appear on the branches. If nothing is done, the needles get a yellow-brown hue.
Schütte is a common coniferous disease.
How to fight . Remove affected branches systematically and on time. Preventive fungicide treatment will help prevent the appearance of fungus. This should be done in the spring and in autumn time... The following drugs have proven themselves well - Quadris, Skor, Strobi, Ridomil Gold, Tilt.
The second most common disease - rust... Caused by basidiomycetes. It manifests itself in the form of yellow-orange growths on the branches. The peculiarity is that not only the juniper is affected, but also neighboring plants - two carriers are needed for the pathogen to pass the cycle. At first, the spores are carried by the wind to apple, pear, hawthorn or mountain ash. Kidney-shaped mounds and rusty spots form on the pages, from which spores spill out, which later fall on the juniper. It is curious that the yellow-orange growths are not immediately noticeable - approximately in the second year after the end of the lesion. The first warning signs that cannot be ignored are thickenings and wounds on the branches of the juniper. According to observations, the Cossack and Virginian junipers are prone to rust more than other varieties.
How to fight ... If rust has already appeared, then it is difficult to cure the disease. The first owner must be eliminated. Damaged juniper branches are cut. Pruning is done with a sterile pruner (treat it with alcohol), otherwise it is only possible to worsen the situation. Healthy branches are treated with fungicides. Microfertilizers with an immunomodulatory effect will help to reduce the harmfulness of rust.
Shrinking branches - another headache for gardeners and summer residents. It leads not only to the loss of decorativeness by the bush, but quite often - to death. The causative agents are a large group of fungi that start working in the spring. The needles turn yellow and begin to fall off. Later, small black spores appear on the bark and branches. It was noted that junipers of varieties Skyrocket, Blue Star and Blue Сarpet are most susceptible to drying out.
Sick branches are carefully cut with a pruner.
How to fight ... Sick branches and bark particles are removed, the plant is whisperingly treated with fungicides. Sections and wounds are disinfected with bronze vitriol. Preventive treatment is carried out in the spring and autumn. From time to time - in the summer.
Nectric and biorellic cancer also leads to yellowing of the needles. Much more often the mycelium is on the bark and the spread of the disease is facilitated by mechanical damage to the outer garments of the juniper. The disease progresses rapidly - the branches turn yellow, the bark cracks, longitudinal ulcers appear and the plant begins to die.
How to fight ... If the affected area is huge, then it will hardly be possible to save the juniper. Bad branches are removed, the plant is treated with Vectra, Bayleton, Skor, Tilt preparations. For the purpose of prevention, go every six months (in early spring and in autumn) to spray the bushes with solutions containing copper (Bordeaux mixture, Oxyhom, bronze vitriol, Fitosporin).
Experts recommend changing the drugs - this significantly increases the efficiency of the activities. Along with this, not only the plant is cultivated, but also the land. If the juniper could not be saved, then the land in this place is changed, in extreme cases - disinfected.
With a massive defeat of branches, it is better to remove the plant entirely from the site.
Careful selection of new planting material will help prevent an outbreak of disease. If the health of the bushes raises doubts, it is better not to risk it and treat them with drugs such as Maxim, Quadris, Fitosporin.
Increases the risk of infection in thickened plantings and heavy soils with poor air exchange. The optimal time for prevention is April and October.
Circumstance number 2. Sucking pests
Aphids suck the sap of the plant, which leads to his death.
From time to time, young junipers appear aphid... It delays the development of the plant, leads to twisting and yellowing of the branches. Control measures are to prevent the spread of ants, since they are the ones grazing aphids. Washing the branches with soapy water helps. Do not forget to protect the ground near the juniper, so that the water does not seep to the roots. Washing is repeated a couple of times with an interval of 7-10 days. The harmfulness of aphids is reduced by pruning the shoots on which countless colonies are located.
Juniper Scale no less scary. If the needles began to turn yellow and fall off in June, closely examine the shrub. Perhaps the circumstance is in the rounded larvae, which sit well on needles. The shields are very small (up to 1.5 mm) - it is difficult to notice them. The scabbard sucks the juice from the bark, as a result, the plant changes color and begins to dry out. If pests appeared relatively recently, then carefully clean them off with a knife. In more advanced cases, they are sprayed with insecticides (Aktara, Fufanon, Aktellik). Belts made of straw or burlap, covered with caterpillar glue, are put on the branches - this will prevent the spread of larvae.
Spider mite envelops the juniper with a narrow cobweb, which is why it crumbles and becomes covered first with yellow, and later brown spots... The tick is especially terrible in dry weather with a shortage of liquid in the ground. During one growing season, a female tick gives up to 6 generations, in other words, the harm from the vital activity of spider mites is significant. Careful care and care of still weak bushes will help prevent the appearance of pests. In the summer, spray the branches with a spray bottle. If you find cobwebs, prepare an infusion of dandelion, garlic or colloidal sulfur for spraying. In very neglected settings, acaricides are used.
Gall midges are not at all a harmless mosquito.
Sucking pests prefer young or weakened plants. This is why it is fundamentally important to systematically fertilize, loosen the soil and remove weeds. Great attention should be paid to the quality of the planting material - take the seedlings only from trusted suppliers. The soil at the planting site should be light, fertile with a low acidity level.
Circumstance number 3. Needle-eating pests
In May, purple butterflies can appear over the junipers. If you ignore their fussy fluttering, then in July green caterpillars with a dark red head will settle on the branches. it pine moths... known for their gluttony. In October, the caterpillars suddenly disappear, but one should not rejoice. They go underground or hide in fallen needles in order to winter safely in the pupa stage, and later again begin to destroy the juniper. Control measures include spraying shrubs with enteric insecticides and digging up the ground to destroy pupae.
Juniper sawfly can be identified by green larvae with a brown head and three black stripes on the body. They feed on shoots and needles, turning a fluffy green juniper into a burnt broom. Dig up the soil systematically, destroy the larvae and spray the plant with Karbofos.
The shoot moth loves to feast on young shoots on the needles.
Shoot moth eats away young shoots, which is why the juniper does not grow well, it becomes pale and stunted. go to highlight that the bush is sprayed in this case not with simple insecticides, but with the addition of mineral oils.
Junipers turned yellow: what to do? This question worries many connoisseurs of evergreen shrubs. Is it possible to expand the effectiveness of ongoing health improvement activities? What do the experts recommend?
- to eliminate fungi, use fungicides, insects and their larvae - insecticides, ticks - acaricides;
- process the bushes a couple of times until complete recovery with an interval of 2 weeks;
- spraying should not be carried out in windy weather;
- the optimal time for disinfection is morning or evening of a warm day;
- in case of fungal diseases, cut branches are treated with bronze vitriol and covered with oil paint on drying oil;
- the following cocktail has proven itself excellently: Epin (1 ampoule) + Zircon (1 ampoule) + 5 liters of water. This mixture is abundantly sprayed with yellowed needles. Perhaps a couple of times with an interval of a couple of days.
If the needles fall off only on the inner side of the crown and only in September, then, most likely, nothing terrible happens. This is a natural process of changing a fur coat, which lasts 2-3 years. At the end of the falling of the old needles under it, you will notice a new one - young and beautiful.
But if the needles fall out all over the crown, then perhaps the circumstance lies in the excessive gas pollution of the atmosphere. In addition, yellowing may be caused by acid rain. Recently, unfortunately, this happens quite often.
Don't expect instant results anyway. The needles take a long time to recover. From time to time it takes 2-3 years.
Other circumstances of juniper yellowing
Not only fungi and pests contribute to yellowing of needles. In order for the juniper to please the eye, it is fundamentally important to arm yourself with the knowledge of correct planting and cultivation.
One of the most common causes of yellowing of needles is drying out of the roots. When planting, put a couple of small stones at the bottom of the pit, cover them with earth (mix it with peat, sand and clay) and only later start planting junipers. Do not completely cover the root collar with earth. Do not plant shrubs in the open sun - junipers love partial shade. Avoid strong waterlogging and soil compaction. In spring and autumn, spray with such growth bioregulators as Zircon, Elin, Elin-extra.
Juniper does not like dry land or overly wet.
Overly moist soil can also cause the crown to dry out. The roots start to rot and the needles turn yellow. Transplantation into dry soil, removal of decayed and treatment of healthy roots with Kornevin will help. If the juniper grows in a pot in your home, then it is better to take structured soil. Mix crushed pine bark (approximately 5% of total), uniform amount river sand large fraction and filler for cat latrines (Barsik effect, Barsik standard, Zeolite). The pot must have huge drainage holes.
Many people know that still weak junipers need to be covered for the winter, but not everyone knows that, for example, it is forbidden to do this with lutrasil, agrotherm or spunbond. These materials not only let the sun's rays through, but also retain moisture, which leads to yellowing of the needles - to frost and sunburn. Young bushes are very sensitive to the spring sun. In March, they need to be covered with burlap. It is possible to cover the crown with it from above, or it is possible to pull it over the frame, placing such a screen on the sunny side. Adult plants are not afraid of frost, but they will be able to suffer from the spring sun, therefore it is also better to cover them.
Juniper needles turn yellow with an increase in alkali and acid in the soil. It is possible to check the level of their content through a test that is sold in any specialized store. If you keep dogs, then keep them away from the trees. Animal urine burns the needles and increases the alkali content in the earth.
The best treatment is prevention. Take care of the juniper - shelter from the destructive spring sun, loosen the ground, prevent the roots from drying out or rotting, and inspect the shrub as often as possible for warning signs. If you do this invariably, then the plant will be healthy, accordingly, it will delight you with the beauty and stunning smell of needles.
Juniper or heather is an evergreen conifers family Cypress. Juniper berries are used for cooking, and very often they are made from them. medicines... Despite the large number of advantages, the shrub also has disadvantages. This is a very capricious plant to care for.
If at first glance it may seem that there will be no hassle with a juniper, in practice this turns out to be far from the case. Many gardeners who cultivate heather are familiar with the situation when, after winter, in the spring, the needles begin to turn yellow. There can be many reasons why this happens. First of all, this is the development of diseases and the appearance various pests... Another reason why the needles turn yellow may be improper care behind the bush.
Juniper disease
In the spring, the needles can turn yellow due to the development of diseases such as:
- Schütte;
- Rust;
- Fungal diseases;
It is worth telling in more detail about each of them.
- 1. Schütte.
Schütte Is one of the most common diseases of heather. The first sign is yellowed needles.
Then it dies off and begins to fall off. This disease affects, as a rule, weak bushes growing in the shade or on very wet soils. It is possible to identify shute at the beginning of summer, when small black spores of a round shape appear on the needles. If the disease is neglected, then the needles take on a yellow-brown color. To prevent disease, it is necessary to carry out preventive procedures. For this, you can use fungicides, for example, "Skor", "Ridomil Gold" or "Quadris". The bushes are sprayed in spring and autumn.
- 2. Rust.
Rust is another common disease that affects pine needles. Basidiomycetes are the causative agents of rust. A characteristic sign of rust is small orange-yellow growths that appear on the needles. The peculiarity of rust is that two carriers are needed for its appearance. The spores of fungi are carried by the wind to the foliage of apple trees, pears or mountain ash, where then small tubercles with spores appear. Later, spores spill out of them, which later fall on the needles. The orange-yellow growths on the needles are not visible immediately, but two years after the onset of the disease.
Dealing with it is quite problematic and it is not always possible to do so. First of all, you need to get rid of the media. The damaged stems of heather are then trimmed. You need to cut them off with a sterile pruner, which must be treated with alcohol in the process. Fungicides can be used to combat rust. For prevention, you can use fertilizers with an immunomodulatory effect.
- 3. Fungal diseases.
Fungal diseases very often not only spoil the appearance of the plant, but also lead to its death. Fungi begin to activate in the spring. The first sign of the onset of the disease is the drying out of the branches, and the needles turn yellow and fall off. Small dark-colored spores appear on the bark. To get rid of the fungus, it is necessary to cut off the affected branches and parts of the bark. Then treat the bush with fungicides. It is advisable to process the sections on the branches with copper sulfate. Preventive procedures can be carried out in spring and autumn.
- 4. Nectric and biorellic cancer.
Nectric carcinoma or biotorella carcinoma causes fungi. As a rule, the mycelium is located on the bark itself. The disease spreads rapidly through the bush. The branches turn yellow, the bark begins to crack. Then sores appear on the branches, after which the plant dies.
In the event that more than half of the bush is affected, then it will not be possible to save it. If a small part is affected, the diseased branches must be cut off, and the heather itself must be treated with such drugs as "Vector", "Skor" or "Tilt".
In order to prevent the appearance of fungi, preventive procedures can be carried out twice in one year (in autumn and spring). Healthy bushes can be treated with Bordeaux liquid or phytosporin. In the event that the bush could not be saved, then it is necessary to replace the soil in its place, or disinfect it.
Pest control
Quite often, the cause of yellowing of the needles is precisely various insects. The most common are:
- Shield;
- Spider mite;
- Sawfly;
- Shoot moth;
- 6. Gall midges.
- 1. Aphids.
Aphids suck all the juices from the heather, which delays its development. The branches first curl, and then yellowness will appear. It is necessary to take into account the fact that if aphids appeared, then ants also appeared. It is with them that you need to fight in the first place. For these purposes, you can use a soapy solution. Before watering the branches with soapy water, cover the soil around the shrub so that the solution does not penetrate to the roots. The procedure should be repeated every 10 days until the aphids and ants are gone.
- 2. Shield.
Another dangerous pest is the juniper scale insect. The needles begin to turn yellow in early summer. In this case, the branches should be inspected for small brown larvae. Sometimes it is very difficult to notice. If there are not very many larvae on the branches, then they can simply be cleaned off with a knife. In the event that the state is neglected, then the shrub must be treated with "Aktar" or "Fufanon".
- 3. Spider mite.
The mite envelops the thin spiderweb branches of the plant, after which the needles begin to turn yellow and become covered with brown spots, and then crumble. Especially often spider mite appears in dry weather. To prevent its appearance, seedlings need to be regularly sprayed with a spray bottle. If a mite was found on the plants, then the shrub must be sprayed with dandelion infusion. If there are a lot of ticks, then you can use acaricides.
- 4. Sawfly.
The sawfly is a small green caterpillar with a black head and black dots on its body that gnaws at the needles. To get rid of it, you should periodically dig up the soil and destroy the larvae. The plant itself can be sprayed with Karbofos.
- 5. Shoot moth.
As a rule, the shoot moth feeds on young shoots, which causes the shrub to stop growing. You can get rid of moths by spraying heather with insecticides and mineral oils.
- 6. Gall midges.
Gall midges lay their larvae on branches, which eat the plant, thereby causing the bark to crack and the needles to yellow. The branches affected by the larvae must be cut off and burned, and the bush itself is sprayed with insecticides.
What to do if the needles turn yellow?
In order to prevent this problem, preventive measures can be taken in advance. Special attention you need to pay attention to preparing the bushes for winter. Many insects prefer to spend the winter in juniper bushes, and with the onset of spring, feed on plant juices. In the event that the needles have begun to turn yellow, urgent action is needed.
Evergreen junipers (Juniperus), along with pines and spruces, rightfully occupy the top lines in the list of plants. middle band... High winter hardiness and drought resistance of juniper, good shearing tolerance in combination with a pleasant aroma of needles make this shrub indispensable for landscape design... The variety of species and varieties of juniper allows you to choose the desired habit of the bush and texture of the needles for both single and group planting, alpine slides. Particularly popular are juniper hedges, which can be cut to the desired height and profile.
Bahamut Chao / Flickr.com
Junipers in the spring often do not please garden owners. They are considered the most unpretentious plantsHowever, in fact, it turns out that it is difficult to care for these evergreens and they are sick more often than other shrubs due to their tendency to fungal diseases. This is reflected in the yellowing and gradual drying of the needles on junipers for no apparent reason in late spring - early summer. Sometimes this is due to sunburnwhich are fairly easy to distinguish. They appear on the juniper bushes on the south side.
F. D. Richards / Flickr.com
But with fungal diseases, you need to regularly fight with preventive spraying with fungicidal and copper-containing preparations. In humid areas at the beginning of summer, you can find junipers, the needles of which on individual branches have acquired a light brown tint or opal. On individual needles, dark round or elliptical dots are noticeable. These are signs of conifers. it fungal disease affects the most weakened coniferous shrubs. Branches with fallen or yellowed needles must be removed, and the remaining healthy parts of the plant should be sprayed with fungicides in May and October.
Delphine Ménard / Flickr.com
Only in the second or third year after the defeat of juniper and thuja with rust, bright orange oily growths appear on the needles. Cossack and Virginia junipers most often get sick with rust. A feature of this disease is the presence of a nearby deciduous infected fruit tree "Master". The leaves of pears and apple trees are affected first, bumps and rusty spots form on them, from which spores pour out onto the juniper. On conifers, rust does not appear immediately, but when the disease has already spread quite widely, so it is difficult to cure it. The first step is to remove the damaged parts of the juniper, and carefully treat the remaining crown with a fungicidal preparation.
William Avery Hudson / Flickr.com
Drying of branches in spring, in which the needles turn yellow and begin to fall off, is also caused by some classes of fungi. On neglected plants, dark small spores appear on the bark of the trunk. Rocky juniper ("Skyrocket" variety) and scaly ("Blue Star", "Blue Carpet") are especially susceptible to this disease. Drying control measures are the same as for other fungal diseases: remove all damaged branches and spray with fungicides.
Rosita Choque / Flickr.com
If a reddish tint appears on the dried branches at the top of the juniper, then you should start worrying. These are signs of trachyomycotic wilting. Junipers Virginia, Cossack and drooping junipers are susceptible to this dangerous disease. hybrid varieties... The disease is transmitted through the soil and through infected seedlings. The roots of the juniper turn brown, spores form on them, the mycelium of the fungus affects the entire plant, which dies. A withered plant should be removed immediately, and the soil in place of the dead bush should be completely replaced. If the variety is very valuable, then you can remove some of the branches, and try to preserve it by regularly spraying with fungicidal preparations.
5u5 / Flickr.com
Among the reasons for the yellowing of juniper needles in the spring can be the development of cancer foci on the trunks and branches of plants. Mechanical damage to the bark increases the risk of developing cancerous growths on juniper, these areas are quickly colonized by fungi. In the infected areas, the growth rate of the wood changes, the juniper branches above the lesion turn yellow and dry out. It is very difficult to cure cancer on a juniper, so the affected branches are completely removed, the remaining parts are sprayed with copper preparations.
Matthew Beziat / Flickr.com
To prevent the transfer of the disease to healthy branches and individual specimens, cuts and cuts on juniper branches are lubricated with a solution of copper sulfate. The tool, which is used for pruning affected plants, is repeatedly wiped with alcohol in the process. In spring (in April) and in autumn (in October), for prophylaxis, juniper is sprayed with copper preparations (it can be a solution of copper sulfate, Bordeaux liquid or commercial preparations like "Oxyhom").
It is recommended to change the preparations for spraying juniper in order to increase their effectiveness. To accelerate the growth of needles and increase stress resistance, juniper is sprayed with anti-stress drugs ("Epin", "Zircon"). They will improve the condition of the needles and accelerate their growth on healthy plants. To avoid infection of juniper with fungal diseases, the roots of juniper seedlings before planting should be soaked for 2-3 hours in a solution of fungicidal preparations, such as "Maxim" or "Fitosporin". Proper agricultural technology is a guarantee that the junipers in your garden will delight you with juicy green needles all year round.