General information

Irises: pests and diseases


The description of diseases of irises with a photo will help to recognize bacterial and viral infections in a timely manner. Knowing why the leaves turn yellow, the shoots dry out and the color falls, you can choose effective methods of control and save the rest of the plants from the spread of infection.

There are more than 800 types of irises in the world. Despite the fact that these ornamental plants are considered to be quite unpretentious to the growing conditions, they, like other garden crops, can be attacked by various pests and affect bacterial, fungal or viral diseases. Let's try to figure out in order with all the possible dangers for irises and the most effective measures to prevent and control them.

Iris mosaic

This disease, which manifests itself in small stripes and light speckled spots on the leaves, causes a specific virus that, as a rule, suffers aphids. Bushes struck with a mosaic noticeably lag behind in growth, produce short peduncles and too colorful flowers with divorces, darker than their main color.

Effective methods of dealing with this disease have not yet been found by gardeners, so the main task is timely preventive measures, namely:

  • immediate removal of infected seedlings,
  • timely watering, fertilization and spraying of irises from insects by chemical and biological preparations (“Golden Iskra”, “Aktellik”, “Furranon”, “Kinmiks”, “Arrivo”, “Konfidor”).

Soft Bacterial Rot

It can be found at the beginning of spring on characteristic brown spots on the overwintering foliage. These shoots and continue to grow with areas of dead tissue, and then begin to rot at the base. Often the disease affects the root of the iris, which softens and acquires an unpleasant putrid odor.

Bacterial rot can persist in the remnants of diseased plants, subsequently infecting the soil, therefore it is very important to carefully collect and destroy them at the end of the season, as well as to treat the soil with antibacterial agents. For these purposes, the universal pesticide "Diazon" is suitable.

At the first signs of iris disease, their affected tissues should be removed, cleaned to healthy areas, cauterizing sections with potassium permanganate. In the future, for reproduction should be used only proven material for planting.


Each garden will be decorated with beautiful irises of the disease and the treatment of which, along with preventive treatments, should be performed in a timely and regular manner. Fungal viruses are another problem faced by both beginners and experienced growers. When Alternaria at the edges of the leaves appears black bloom.

Over time, these leaves dry completely and fall away from the stem. If infected plants are not removed, the infection may persist in the soil until the next season in the form of spores. Get rid of this scourge will help systematic spraying beds Bordeaux mixture.

Iris rust

As a result of this fungal disease, a lot of brown pustules appear on the tips of the leaves, which lead to their yellowing and further drying. On the affected plants with the onset of autumn, you can notice a special coating where the wintering stage of the fungus is located. Its spores are well tolerated by severe frosts and with the arrival of the first heat they begin to infect young shoots.

Soil drainage in flowerbeds, the destruction of diseased leaves and the treatment of those that have been preserved with sulfur-containing preparations (Tiovit, garden and colloidal sulfur) will help fight rust. Spraying should be done every 2 weeks until the disappearance of signs of the disease.

Numerous dark markings with watery edges, which manifest the disease, leads to premature drying of the affected leaves. Ascochitis, as well as other fungal infections persists in plant debris and soil. To prevent its reproduction, it is necessary to process irises before and after the start of flowering with drugs with copper - copper sulphate or "Home".


Its signs are round or oval markings on the foliage, which initially have a yellow color, and then become gray-brown. After some time after infection, not only these spots begin to darken, but nearby tissues, on the surface of which fungal spores are formed.

The treatment of irises with copper-containing compounds and the collection and burning of plants at the end of autumn will help to get rid of heterosporia.

Gray rot

If it is your turn to think about why the leaves of the irises turn yellow after flowering, you can be sure that the plants attacked two fungi-pathogens at once. The first of them affects the rhizome with dry rot and contributes to the appearance of specific round and dense neoplasms on it.

The second fungus is activated in wet weather, striking foliage and flowers, painting them with a brown tinge and covering them with a grayish bloom. Yellowing spots are a sign of the development of spores, which subsequently remain in the soil after the end of flowering.

One can get rid of gray rot by selecting healthy roots for reproduction, planting them in drained soil and, of course, getting rid of already infected irises.

Aphid bean

This dark green or brown insect to taste not only bearded irises. Aphids gladly settle on buds, shoots and leafy parts of asters, gladioli, dahlias and other residents of flower beds. As a result, the stem is deformed, leaves begin to curl and lose color.

Among the main methods of dealing with aphids are:

  • regular weeding of weed beds and potash phosphate fertilizers,
  • individual aphids can be collected from irises manually, and when their mass colonies are detected, insecticidal tinctures or chemical preparations should be sprayed the same as in the case of mosaic disease.

Onion Nematode

This is a small white worm that lives in the bulbs and seeds of plants. As a rule, it is suitable for breeding in a humid environment, but in a strong drought this pest remains viable for a long time. The larvae and adults of nematodes suck out sap from plants, which leads to stem swelling and irregularly shaped peduncles. After the final withering of the irises, the pests burrow into the ground in search of their new “victim”.

The main thing in the fight against nematodes is the observance of crop rotation, in which the irises need to be returned to their former sites only after a couple of years. It is also good to organize nearby flower beds with carrots and dry the bulbs before storing them in the winter.

Root tick

This pest is not in vain called the onion mite, because, spreading everywhere, it can damage during storage not only irises, but also hyacinths, daffodils and other onion crops.

An insect with a brown calf chooses weakened plants for settlement, therefore, when planting material, it will not be superfluous to treat it with Antiklesh or pour it with usual chalk (only 20 g of grated chalk or lime will be needed per kilogram of bulbs). Before putting into storage, the room must be decontaminated for 2 days, smoking with special sulfur checkers, and the irises themselves should be thoroughly dried.

Diseases of irises and their treatment will not be a problem if you use the above tips. Pay attention to the removal of weeds, loosening and tillage, meticulous care after flowering and processing of bulbs before laying for winter storage, then bright flowers will be an excellent decoration and a real pride of your front garden.

Treatment, prevention of bacteriosis

As soon as the snow melts, you should check the irises. Protection against pests and diseases begins with the provision of outflow of melt water, if there is no natural slope at the flower bed. In winter, as a disease prevention, wrapping iris roots against freezing is used. Rhizomes, damaged by frost, are the first to be at risk of disease, and therefore must be destroyed.

In the event that the bacteriosis has not completely damaged the root, only the areas affected by bacteria are cut out, and the cut points are smeared with green paint or ash is rubbed into them. This work is carried out before flowering.

Also, for preventive purposes, the foliage should be sprayed with a solution of urea mixed with 12% sulfur. During the transplantation of young rhizomes, it is recommended to hold them in a solution of potassium permanganate for 15-20 minutes for disinfection.

Wet rot

Diseases and pests of irises and the fight against them are quite complex issues. They concern not only rhizomes, but also leaves. The presence of a disease such as wet rot can be noticed when the leaves of the plant begin to turn and dry. At the same time, the iris roots become powdery from the inside, which is not noticeable from the outside.

Wet rot affects flowers and slows down the development of not only irises, but also gladioli, tulips and hyacinths. This bacterium appears in the soil from the manure with which it is fertilized. To avoid infection, before planting irises (pests and diseases, then bypass them) are treated in a solution of potassium permanganate for 30 minutes. It is enough to put half a teaspoon of the substance in 0.5 liters of water, lower the rhizome and pickle it.

Gray rot (fusarium), which affects both the roots and foliage of the plant, is also dangerous for the iris. At the same time, a gray bloom appears on the leaves, which causes them to rot and die. The roots are affected by dry rot, which appears due to the increased nitrogen content, therefore, feeding the soil with mineral fertilizers, one should strictly follow the dosage.

Properly chosen landing site will be a good prevention of the disease. And the pests of irises, and their treatment will not become irreparable damage to the entire flowerbed, if you plant flowers either on a natural dais, or on a loose raised bed.

A plot of soil contaminated with fungus can be the culprit of contamination of all the land near the house, if the already infected iris tubers are cut and transplanted. The fungus remains in the soil and when favorable conditions appear (high humidity, temperature + 12-17 degrees) will damage the surrounding plants.

The first sign of the disease is the appearance of a gray spot on the rhizome. The flesh under it becomes brown and friable, and inside the root turns black. For safety, irises (pests and diseases then recede) must be treated with copper sulphate or bicarbonate soda of 5% strength before planting.

Another simple method of prevention is the treatment of garden tools before work.

Botrytis and rust

Irises are often affected by fungal diseases. For example, Botrytis cause two fungi at once - Botrytis convoluta and Sclerotium rolfsii. They can develop with improper storage of rhizomes in conditions of high humidity and poor ventilation.

If such planting material is planted, then at the onset of rain the fungi begin to multiply rapidly, destroying the plant completely and affecting the neighboring cultures.

For prophylaxis, it is necessary to store delants in the correct conditions and pickle them with a solution of triazole class fungicides.

Leaf mosaic

Diseases and pests of irises and their treatment are not limited solely to fungal diseases. Plants are also susceptible to viruses. The flower mosaic of leaves is well known to flower growers, in which they become yellow-green and dry quickly.

Damaged foliage should be immediately cut off and burned, and the bush itself should be sprayed with a 0.2% solution of copper oxychloride and Ridomil Gold.

In order to notice the disease of flowers in time, one should carefully look at the color of their flowers. If they become spotty or melted, and light flowers become dirty opaque, then the plant is infected with a virus.

For prophylaxis, it is necessary to decontaminate the inventory each time before gardening, spray the area with fungicides and clean it of weeds.

Thrips, Nematodes and Bronzik Beetle

Many irises, diseases and pests (photo confirmation) which most often affect the roots, suffer from small insects - thrips, which settle in the leaf axils. They feed on plant sap, causing deformation at the same time. Most of all thrips love Siberian and Japanese varieties of irises, but do not disdain, and "bearded" species.

As these sucking insects “conquer” the plant, its leaves turn brown and dry, and the roots become covered with brown spots.

From thrips can save spraying with an emulsion of karbofos (10%) based on 10 liters of water 75-90 g of the emulsion. Spray should be done once a week.

Nematodes are small translucent worms that are not afraid of frost. They settle at the base and in the plant buds and become more active with the onset of heat. With the “stiletto” they possess, they pierce the epidermis of the leaf and feed on its cell sap. At the puncture site, the leaf turns brown and dies.

Nematodes are often transmitted to garden tools, with weeds and rainwater. Systematic weeding of weeds treated with a 10% formalin solution with inventory and steaming the soil before planting will help avoid contamination.

Large beetles of green color, reaching a length of 2 cm, popularly called bronze. They are activated from the end of May and fly in the gardens in search of pollen, not disdaining also delicate iris flowers. Diseases and pests of irises and their treatment is what the florist needs to have special knowledge about. With the invasion of bronzovok flowers treatment begins with spraying plants "Kinmiksom" at the rate of 2.5 g per 1 l of water.

If there are not very many beetles, they can be picked by hand, and the flowers should be sprayed with a solution of ash for prevention.

Aphids and slugs

In the period of blooming flowers, many insects are activated, which do not bypass the side and irises. Pests and diseases during flowering plants destroy not only the roots and leaves, but also flowers. For example, aphids accumulate in buds and “suck” life out of the plants, feeding on their sap.

Since the aphid multiplies rapidly, the plant can quickly die in a short time. To avoid this, spraying of damaged flowers with a 0.3% carbofos emulsion or 15% phosphamide composition should be carried out.

If there are no chemicals on hand, then a solution of soda ash (0.5%) with soap is suitable. Another way to protect plants from aphids is regular weeding.

Slugs live in the lower tier of leaves and in the upper layers of the soil. During the day, they hide, crawling out for feeding at night. They eat the leaves, and in the rhizomes eat whole cavities. Intensively multiply during periods of rain at a temperature of + 18-20 degrees.

In the form of prevention, it is possible to carry out a deep digging of the earth and the destruction of last year’s leaves. You can get rid of slugs with a folk remedy - sprinkle flowers and closely growing trees with a decoction of bitter pepper.

The land is treated with ash or a mixture of lime and tobacco dust. Also, many gardeners set traps for slugs - dug into the ground bowls of water. When they get into the dishes to get drunk, they can’t get out of there. It remains to destroy them and pour fresh water.

Scoops and Bears

Butterfly caterpillars scoops destroy irises from the inside, gnawing through entire mazes in the stem of a plant. Most of all, they like wet areas, so draining the soil is a preventive method. It is also recommended to loosen the soil in the aisle and destroy weeds, especially during the laying of eggs.

Good effect on diseases and pests of irises Bordeaux liquid, which is made from a mixture of copper sulfate and milk of lime. It should be used before blooming flowers.

If the moment was missed and caterpillars appeared, they are recommended to be sprayed with decoction of Chemeritsa Lobel.

Medvedki have powerful jaws, with which they gnaw through the roots and stems. Irises (diseases and pests, photos confirm this, in most cases less dangerous than this insect) die if the bear colony settles under them.

You can destroy them using bait. To do this, boil 1 kg of grain, add 30 g of oil and 50 g of karbofos and mix well. It is enough to dig this mixture 5 cm into the ground or push it into their burrows.


Wireworm called the larvae of the click beetle, which live in the root zone of flowers. Irises, diseases and pests, the treatment and prevention of which often depend on the quality of digging and loosening the soil, can avoid many health problems if the gardener puts enough effort. To get rid of the wireworm, it is recommended to add anhydrous ammonia to the soil and regularly destroy weeds.

Causes of disease

Every gardener should be familiar with various diseases that can harm the plant. In order to prevent this, you need to know the reasons for their appearance.
Iris diseases are most often caused by:

  • too high soil moisture
  • if there are old bushes and the plant requires rejuvenation,
  • чрезмерное использование органических удобрений,
  • последствия после сильного похолодания или морозов.

Подробнее о болезнях ирисов

Болезни ирисов и борьба с ними фото можно увидеть как в журнал, так и в интернете. О заболеваниях должен знать каждый любитель растений, который собирается выращивать их в саду или на участке около дома. Самый частый недуг, который встречается – это бактериоз. Для него характерным есть поражение корневищ.

The disease causes decay and unpleasant smell. This disease most often occurs due to lowering the temperature to 3-5 degrees. If not to take measures, their treatment in late time will not give results.

To avoid such a disease, you need to carefully inspect the bush, do it better at the end of winter, during the period of snow melting. To bacteriosis could not develop on the irises, they should be protected as much as possible from the melt water.

In order to do this, you can use raised beds or plant plants on a natural slope. If rot was found near the rhizome, it should be removed immediately.

After that, carry out the treatment of rhizomes, for this you can use a 10% solution of bleach. If possible, you can apply a solution of potassium permanganate. Such effective means will quickly help to eliminate the signs of bacteriosis.

  • One of the most dangerous diseases of iris is fusarium. The disease is caused by a fungus, affecting both the roots and the stems. The main cause of occurrence is considered to be too much nitrogen in the soil. May occur due to damage to the tubers of the plant. Fusarium often appears where there are adverse climatic conditions.
  • If we talk about how the disease looks, then grayish brown spots start appearing on the plant. The plant may look slightly shriveled. If the treatment is not carried out immediately, the irises in a short time become brownish. It is best to use chemicals for treatment that will not injure the plant.
  • Another disease that occurs in irises is heterosporia. A disease that affects the stems and leaves of irises. Most often begins to spread with the old foliage of the bush. The disease is easily noticed as grayish-white spots begin to appear. A yellowish border also appears on the leaves. If you do not eliminate the disease, the plant may die. To prevent heterosporioz use potassium and phosphorus with the addition of various trace elements. Such substances help the plant to become more resistant and resist infection. In addition to using the tool, you should not forget about clearing the land from weeds, as they can adversely affect the irises. Before processing, it is necessary to clean the shrub from infected leaves and use treatment products.
  • Botrytis can be attributed to fungal diseases, which is considered quite dangerous and often leads to the death of the plant. It often occurs due to poor storage of planting material (especially if there was poor ventilation of the room and high humidity). The disease occurs after planting the plant and begins to actively develop in the soil. To prevent this from happening, you need to store the planting material in a dry room with adequate ventilation. And before planting it is best to treat the rhizomes of plants with special systemic fungicides.
  • Also, from fungal diseases that are often found in irises, there is rust. The reason why the leaves turn yellow is hidden just in such a disease. The disease develops at a temperature of +12 degrees. If you do not carry out treatment, the leaves of irises quickly dry and fall off. To eliminate the fungal disease, the affected leaves must be plucked and burned. This is necessary in order to completely eliminate the fungus, since it can remain in the soil for many years and appear immediately after the snow and frost have melted. In addition, rust can easily affect other plants growing near the iris.

Other common diseases of irises and their treatment

In addition to fungal, the plant can be affected by mycoplasma and viroids. Such diseases differ in their effects on the bush.

Virosis is a dangerous viral disease, and the first sign is its small wrinkles, folds and blistering on the leaflets. The disease can affect the color of the petals. Virosis also leads to frequent fragility of peduncles.

To deal with the illness, the gardener must completely destroy the planting material that has been infected. For prevention, it is recommended to use fungicides to eliminate phytopathogenic fungal diseases.

All gardeners should know that iris diseases and their treatment are due to nematodes. And among the most dangerous can be identified:

Nematodes have the ability to infect rhizomes and provoke decay. It is worth noting that such a disease can affect plant growth and significantly inhibit it. To the plant was not affected by the disease, gardeners recommend regularly clean your site from weeds.

In addition, it is recommended to use various means in the fight against nematodes. The most effective, with this disease is nematocides.

Many gardeners wonder why the disease occurs, because the planting material was of high quality and kept in good conditions, fertilizers were used, but diseases of varying degrees of complexity still overtook the plant.

Here the whole thing can be in the soil. Poor quality soil, lack of components and minerals in it, such as potassium, phosphorus, nitrogen can cause the appearance of diseases.

But it is important to take into account the fact that these substances can influence the state of the plant not only positively, but also destructively. In addition, the iris can be affected by a variety of diseases in the event that there is either too low or high temperatures.

The level of environmental pollution also plays a very important role. Another reason for the emergence of various diseases may be a lack of oxygen in the soil.

Pests that impair the growth of irises

Diseases and pests of irises - this is what can trigger the rapid death of the plant. If we talk about pests, this is a very serious question, and every gardener should know which pests can affect the iris and how to deal with them.
You should not assume that only diseases can destroy a bush; pests in this plan also bring tremendous harm.

The most dangerous pests are thrips. Such insects can not only damage the leaves, but also the rhizomes. But, it is possible to cope with such insects, for this every gardener needs to regularly clean his land from weeds.

In the event that insects have damaged large areas of the territory, you need to use various drugs. All chemicals can be purchased at the garden store, in each case, you need to use a separate drug. To combat thrips use organophosphorus agents.

Among all drugs, experienced gardeners recommend using the Mavrik remedy. The drug has a lot of advantages, the main of which is a small amount of toxins that are in the composition of the product.

Of malicious insects dangerous there is also aphid. Among its features is that it affects the leaves, flowers. The insect multiplies rapidly, which makes the struggle for the plant difficult.

To overcome the pest, it is recommended to use a 0.3% emulsion of carbaphos, a 15% emulsion of phosphamide and a 0.5% solution of soda ash with a solution of soap. During the fight against aphids, do not forget about cleaning the area from weeds, which is also an effective method.

Diseases, pests - all this can cause poor growth of irises in your area.

In order to avoid difficulties with cultivation, you should use the advice of experienced gardeners:

  • so that the irises are not affected by diseases and pests, it is worthwhile to dig the soil regularly,
  • apply pesticides
  • properly store planting material
  • monitor humidity and temperature. Additionally fertilize with nutrients.

Among the harmful insects that can impair the growth of iris - there are also larvae of the May beetle. They can damage the rhizomes and tubers of the bush. To fight pests, you need to regularly dig up the soil and collect all the larvae. Before planting irises, pesticides are recommended.

Read more about it here:

Root (onion) mite

It damages not only irises, but also many other bulbous plants. This pest has a convex, whitish body and 8 limbs, capable of laying 800 eggs per season. For rapid, intensive reproduction, a root mite needs a moist (minimum 60%) and warm environment. Usually affects plants already infected with other pests. Penetrating into the root system, it settles in the cracks of the roots or between the scales. Because of this, the root rots, and the foliage turns yellow. When infecting planting material, it dries out.

As a method of struggle, use the digging of the flower bed in the fall, be sure to remove the still not germinated rhizomes and diseased irises, observe the planting dates. It is advisable for these flowers to choose a place near the carrot bed. Bulb storage should be disinfected with special sulfur checkers, and the bulbs themselves should be dried at a temperature

36 ° C and pour chalk (20 g per 1 kg). Before planting, also use a tick repellent to treat the bulbs.

During the growing season, the treatment of irises from these pests involves spraying with a solution of 0.1% Rogora, 0.2% Trichlormetaphos, 0.2-0.3% Karbofos, or watering 0.2% Keltan, Rogor "and" Chlorofos ". It is also allowed to water the soil with insecticides.

Onion nematodes

This is a dangerous pest of not only irises, but also of many vegetable crops. This 1.5mm white worm infects seeds and plant bulbs, can survive many years of drought, but needs very moist ground for mass distribution. This parasite feeds on the iris juice, retarding their growth, leading to the formation of distorted flowers and swollen stems.

As with the fight against the root mite, it is necessary to decontaminate the storage and dry the onions. For planting pick up a place near the carrot. Using percalcite will destroy the eggs and larvae of nematodes. Suppose also watering with ammonia water and soil treatment with urea.


The larvae of the cockchafer have been living in the ground for several years. They gnaw the roots of irises. Best of all it helps to mechanically remove crunches during deep digging. And since they can be found in manure, before fertilizing the soil, it is worth sifting and removing all the larvae. For the fight also use light traps and the introduction of anhydrous ammonia.

Medvedka has two pairs of wings, front digging feet and strong jaws. It gnaws the roots and stems. Especially dangerous for bearded irises. To protect against the bear, dig deep into the soil, use traps. In the spring, place slate, plywood, etc. on the plot. The insect will crawl under them, and you will need to check such traps and destroy pests. Or place small dung heaps, where the heads will lay eggs, and you can collect insects.

In the autumn, dig several half-meter holes and fill them with manure. Medvedka get there for the winter. And as soon as the frosts come, the manure should be thrown out of the pits. This will lead to the death of the pest. Use of water traps is possible. To do this, fill the jars with water, but not up to the end, but with an indentation of 10 cm and dig them into the ground. Periodically look into the traps and destroy the insects caught there.

Winter scoop

It often hurts on wet lowland soils. As a result of its activity, the stems break off, the foliage turns yellow and fades. In addition, caterpillars scoops can damage the root system, which is then easily affected by disease. At defeat by a scoop on stalks entrance openings at ground level will be noticeable.

To destroy the pupae, dig deeply and periodically loosen the soil. At the beginning of the growing season, spray with 10% solution of Karbofos and repeat the procedure after a week.

Iris family: short description

Before telling you what dangers flower growers dealing with the cultivation of irises may face, it is necessary to briefly describe the features of this plant. Currently, there are many different varieties of the iris family that are optimally adapted to certain climatic conditions. Many of them are rhizomatous. They are perennial, so even a lack of snow cover in the winter, together with fairly low temperatures, can destroy the plant. There is also another variety - bulbous varieties. Gardeners living in Russia, prefer rhizomes representatives. They grow well in our climatic latitudes with the condition of moderate humidity.

The root system in these colors is well developed. Most often, it is located shallowly in the ground, and sometimes even protrudes outside. It consists of a rather thick rhizome, from which thin filamentous processes depart. During flowering irises emit large flowers. Depending on the variety, they can be single or consist of several inflorescences located on a strong peduncle. The range of the palette is so diverse (from white to black) that it is simply not possible to describe everything. Irises inflorescences are either monophonic or multicolored, consisting of two or more shades. The flowering period is at the end of spring and lasts until about mid-June.

The leaves of the family of iris hard and dense. In shape they are elongated and flat, covered with a wax coating with a whitish tinge.

Flowers irises: diseases

Each gardener must take into account the specifics of the region when growing irises. Depending on the climate, plants are subject to certain diseases. For example, the north-western part of Russia is characterized by high humidity, therefore, the local irises often begin to rot the rhizomes, which is why bacteriosis develops. In the southwest, rust is a common problem. Read about these and not only diseases in more details. In order for the reader to better understand what the affected areas look like in the article, photos will be added.

Diseases of irises and the fight against them directly depend on the weather and climatic conditions!

Also, do not exclude pests that can destroy the flower. For example, florists in the southern regions of the constant problems brings Medvedka. Aphids and slugs, unfortunately, are no less harmful to a flower, so it is important to understand that preventive measures taken in time to help avoid various diseases.

Irises are quite unpretentious flowers, they are resistant to diseases. However, if you violate the rules of care, even these plants become defenseless from all sorts of effects. The most common problem is considered rotting rhizomes. This disease of irises (photo of tubers, see below) is called bacteriosis. It is quite dangerous and can lead to the death of the flower.

The causative agent of this disease is Erwinia carotovora. The bacterium is actively developing at high humidity, so in no case should the soil be saturated with water. It directly affects the rhizome of the plant and causes them to rot. Also, do not saturate the ground with organic matter and thin out the flowers in time.

What are the signs of bacteriosis?

  • In a healthy flower, the rhizomes are quite hard. In a sick plant, they become soft.
  • The process of decay is accompanied by a strong unpleasant smell.
  • The leaves turn yellow, and then completely disappear.

If the rhizomes are badly damaged, then the flower cannot be cured. Considering that bacteriosis develops rather quickly at a temperature of + 13 ... + 17 ° С, the damage that diseases and pests cause to irises is already irreparable. The only thing that can be done is to separate the still healthy plants from the sick. The latter will need to burn. If the soil is heavily affected, then it is recommended to transplant flowers that are not infected with bacteriosis to another soil.

Prevention and treatment of bacteriosis

As soon as the snow cover melts, it is already necessary to take measures to eliminate all possible diseases of the irises. Fighting them will be much more difficult than prevention. First of all, we must take care of the outflow of melt water. This is especially true if the bed does not have a natural slope.

If there is little snow during the winter and the air temperature is very low, then it is recommended to protect the rhizomes from freezing. It is important to understand that bacteriosis will hit first of all those flowers whose roots were damaged by frost. To avoid such a situation, you just need to wrap them.

At the initial stage of bacterial disease, only some of the rhizome is affected. In this case, it can be removed, and the place cut cut with ash. Such measures can be carried out before flowering.

When transplanting iris, it is recommended to treat the roots with a solution of potassium permanganate. To do this, they are soaked for 15-20 minutes. Also, it does not hurt to treat foliage with urea diluted with sulfur (12%).

In addition to bacteriosis, there are other diseases of irises, and their treatment is not always possible. A rather dangerous disease is fusarium. This gray rot affects not only the roots, but even the leaves. The diseased plant is covered with gray bloom, which provokes the process of decay. The main reason for its occurrence is considered to be a surplus of nitrogen in the soil. Such a situation can result from improper use of mineral fertilizers, that is, overdosing.

Infected tubers are carriers of fusarium. Если пересадить их на другое место, то грибок, попадая в почву, начнет размножаться, что может привести к заражению всего земельного участка. Наиболее благоприятные условия для него – температура воздуха +12…+17 °С и переизбыток влаги в грунте.

Первым признаком развития фузариоза является наличие серых пятен на корневище. Оно становится довольно рыхлым.

In order to avoid the development of this disease, it is recommended to carefully and regularly handle garden tools, choose a place on a hill for a flower bed and be sure to treat the roots with copper sulphate with 5% bicarbonate soda.

Pests: bronze beetle and nematodes

Bronze beetles appear in flower beds in late spring. They are quite large - about 2 cm. They have a characteristic green tint. To protect the irises from them, you can "Kinmiksom." Diluted as follows: in one liter of water 2.5 g of the drug. In order to prevent these beetles, you can use the ash solution.

Diseases of irises cause nematodes. These worms feed on cell sap. Do not die even in severe frost. The leaf at the puncture site first begins to grow brown, then dies off. Infecting the soil with nematodes can be done in several ways:

  • through weeds and inventory,
  • through rainwater.

Bears and scoops

Bears can deliver a lot of trouble to gardeners. They inhabit the soil. Moving, their powerful jaws damage the roots and stems of plants. To combat these pests, you must use bait. In the ground, a mixture consisting of karbofos, grain and oil is added dropwise.

A lot of harm and scoops bring. These caterpillars, falling into the stem, eats away everything from the inside. Their large accumulation can be found in wet areas of the soil. For the purposes of prophylaxis, it is recommended not to allow the beds to grow over with weeds, as well as to regularly loosen the ground between rows. This should be done especially carefully during the laying of eggs. It is very good in case of iris disease caused by butterfly caterpillars to use Bordeaux liquid. The solution is made of milk of lime and copper sulphate. You can spray the plants only before the beginning of the flowering period. This will help avoid pest problems. However, if the moment is already missed, then it is recommended to process irises by hellebess Lobel.

Diseases of irises and their treatment

In comparison with other perennial plants, irises are less susceptible to various diseases, but still not 100% protected from them.

Fungal, viral, and bacterial diseases can run amok in flowerbeds. An experienced gardener should be able to distinguish and treat them.

As a preventive measure, spraying with Bordeaux mixture before and after flowering works fine..

For convenience, the diseases are listed below in alphabetical order.

Ascochitis or leaf spot

Also a fungal disease.

Signs of: brown leaves appear on leaf edges. The foliage begins to dry.

What to do: to overcome the disease will help drugs with a copper content. It should be noted that the disease remains both in the ground and in all parts of the plant. The method is suitable for any kind of iris spotting.

Dry rot or fusarium

Signs of: infection begins with a rhizome and gradually clogs all channels. The leaves quickly fade, the plant dies.

What to do: destroy or take out a dead plant. To process the neighboring plants with fungicides, and the place of growth of the deceased pour copper oxychloride.

During the flowering spraying can not be carried out!

The most important thing in the fight against disease is the prevention and compliance with agricultural technology. Beautiful and healthy plants for you!


As a preventive measure against all types of blotches, spraying flowers with a 1% Bordeaux mixture is used.

With such a disease of irises, like rust, brown leaves appear on the leaves, around which the fabric dies, and with time the foliage dries, twists and dies. Stems are deformed. Spores can persist in soil and plant debris.

You also need to comply with the culture (plant the iris again at the same place after 3-4 years), drain the soil, destroy all the infected leaves and treat the rest with the solution with sulfur (repeat every 2 weeks until the symptoms of the disease disappear).

Dry rot (Fusarium)

Dry rot spreads from the roots, where, growing, clogs the vessels of the plant. Rhizomes dry. During the growing season it has the appearance of rapid drying of flowers and leaves. Dead plants need to be removed from the site, and their places of growth treated with copper oxychloride. Spray the healthy irises with a fungicide.

Methods of prevention from diseases and pests

As you can see, the best prevention from any diseases and pests will be compliance with the rules of agricultural engineering, proper and timely fertilization, watering, digging the soil, removing weeds, as well as the selection of high-quality planting material and processing special means as needed.

We hope that this article about pests, diseases of irises and their treatment was useful for you. Pay attention to these colors and provide proper care, and you will only need the information provided as a preventive measure.

Bacteriosis - wet rot of roots

Pathogens are bacteria of the groups Erwinia aroidea, Pseudomonas iridis. The disease affects the base of the leaf and the root neck of the plant.

  • excessive moisture
  • thickening of crops,
  • freezing of stalks.

At the beginning, the center is small, hardly noticeable. Infected leaves dry. The disease goes into the middle of the root. Prevention:

  • placement of landings on well-drained soils,
  • avoid damage to plant parts, rhizomes,
  • pest control.

Tip! Planted on the slope of the iris, will be the least exposed to infections of the fungus.

Of the drugs that can cure an infected plant, botanists recommend doxycycline powder. It is also used to combat decay in orchids. The sites causing suspicions are treated with the agent. Obviously affected areas are removed, antibiotic is applied to the sections. In wet and wet weather, the treatment is not carried out.

Fusarium and iris heterosporia

Fusarium affects the vascular system of the plant. The causative agent is the fungus Fusarium oxysporum.
The most dangerous time for infections is the temperature fluctuation in wet weather from + 2 ° С to + 32 ° С. Infection from soil of high humidity, gets on the rhizome. Fabric softened, covered with gray-brown spots. The root turns black and dries out. Prevention:

  • strict observance of the agrotechnical type,
  • top dressing according to the norms
  • Do not injure parts of the plant.

Dead or affected by Fusarium plants, dig. The place is treated with copper oxychloride. The rest of the plant irrigated with any fungicides. Re-plant irises should be on the site after 4-5 years.

In neglected stands of iris, with excessive soil moisture and lack of phosphorus, heterosporia is activated. The causative agent of the infection is Heterospotium gracile fungus. Recognize diseased plants can be light brown oblong spots on the leaves. Severe infection causes the death of the leaves, but not of the culture itself. Prevention:

  • neutral ph level on the soil
  • timely removal of diseased and dead leaves,
  • the introduction of phosphate fertilizers (superphosphate).

Malicious insects for iris

Thrips. Sucking juices, cause deformation and wilting of the iris. To combat used karbofos emulsion. The calculation is as follows: 75-95 g of solution per 10 liters of water.

Nematode worms. The leaves struck with worms die off. Nematodes fall on irises along with precipitation and from weeds. Prevention:

  • landing weeding,
  • disinfection of garden tools in formalin solution.

Bronze beetles. Beetles can be collected manually. If their number is large, treat the plants with ashes or “Kinmiksom”. Calculation of the drug: 2.5 g per 1 liter of water.

Aphid. A common cause of the disease is "mosaic". Infected plants are lagging behind in development, have shortened peduncles and spots on flowers. To save the iris with a progressive mosaic is almost impossible. To combat aphids use drugs: Aktara, Inta-Vir. The folk method is treatment with a solution of soda ash with households. soap

Slugs. A mixture of lime and tobacco is used against slugs. Flowers are sprayed with bitter pepper tincture. The soil is freed from slugs by digging deep and removing last year’s plant residues.

Scoops. Before blooming, the plants are sprayed with Bordeaux mixture. If the caterpillars are found in flowers, then a decoction of hellebore Lobel.

Medvedki. To destroy the bears, insect holes are poured with a soap solution (10 g of soap and 50 g of laundry detergent are taken for 10 liters of water). Effective poisonous bait from a mixture of wheat grains, oil and karbofos.

Wireworms. Affect roots. To fight in the ground make anhydrous ammonia and regularly weed.

Early detection of the first foci of infection and pests, as well as competent agrotechnology - success in breeding the most exotic and "capricious" varieties of iris.