Why do spots appear on the leaves of roses and what to do?

Rose is a very whimsical plant and often suffers from various diseases that spoil its appearance. Because of what spots appear on the pink bush and what methods of dealing with them exist, we will tell you in this article.

The spots that appear on the leaves of the rose often indicate such a common disease as brown spot, another name is cercospora. The causative agent of this disease is a harmful pathogenic fungus, which develops and spreads especially actively in the garden in conditions of high humidity and heat. It can also appear due to a large or, on the contrary, insufficient amount of fertilizers, gross mistakes in care and with active attacks from harmful insects.

As a rule, brown spot makes itself felt in the middle of summer. During this period, the fungus begins to infect the leaves and young shoots. The specks initially appear on the lower leaves. At first, they look like small brownish or brownish dots that spread along the outside of the leaf blade and over time they simply merge with each other.

Sick leaves crumble over time, and the pathogenic fungus itself passes to the petals and buds. As a result, the shrub loses its decorative effect and becomes bald. The buds on those shoots that were affected do not open, and in the areas where the spots are located, pads appear where the fungal spores are located.

At the final stage of the development of the disease, shoots begin to dry, which eventually die off, and the fungus itself begins to infect the root system. Further, the process of sap flow of the plant is disrupted, which leads to the death of the rose bush.

It is quite difficult to treat this disease, especially at an advanced stage. Many people mistakenly believe that the fungus is able to leave itself along with the fallen leaves, but this is not the case. Its spores are quite successfully able to survive the winter in old foliage or inside a shrub, and when warm comes, they become active again. Therefore, the first thing to do is remove all old foliage when it comes to the end of the season. Otherwise, you need to cut off all affected areas to stop the spread of the fungus.

Next, it is worth resorting to the help of fungicidal preparations. It is better to process plants with such means as "Profit", "Skor", "Strobi", Bordeaux liquid or "Oxyhom". They are the ones most in demand among experienced gardeners. Do not neglect the cultivation of the soil around the bushes, which are sick with brown spot. To do this, you can also resort to using Bordeaux liquid.

You can also fight a harmful fungus with the help of folk remedies. This should be done when cases are not started or for preventive purposes. Otherwise, it would be better to combine such products with fungicides. So, in the fight against brown spot, homemade solutions are often used, such as tinctures based on onion or garlic husks, from dandelions.

If the leaves, flowers, shoots and stems of the rose are covered with dark spots, then the reason for this is usually black spot. This disease is triggered by a harmful fungus and is activated after the first wave of flowering.

The occurrence of this disease is indicated by dark spots that have appeared on the plant sites, which have a rounded or oblong shape. First of all, the lower leaves are usually affected. However, over time, the disease successfully affects the top of the bush.

Those leaves that have been affected by black spot begin to fall off. At the same time, the shrub does not bloom and the immunity is noticeably reduced, which makes it less resistant to attacks from various pests. The diseased rose also loses its resistance to frost, and therefore can easily freeze out in winter.

In this case, it is possible to save the plant, but all the necessary measures must be taken immediately.

• So, first you need to eliminate all those leaves on which black spots appeared. You also need to remove fallen leaves.
• All plant residues must be burned, since fungus could well remain on them, and therefore they cannot be added to the compost.
• After that, the soil around the diseased bush should be sprinkled with ash.
• If the bush was badly affected, then in this case it is worth resorting to the use of fungicidal agents, which contain a large amount of copper - these include "HOM", "Oxyhom" and Bordeaux liquid.
• Plants should be processed in the evening at intervals of 2 weeks if the weather is warm, and at intervals of 7 days if there is precipitation. At the same time, we note that for the greatest effect, both the upper and lower sides of the leaf blade should be sprayed.

The appearance of light spots on the leaf blade indicates that the plant is sick with powdery mildew or downy mildew. The first disease is activated, as a rule, in conditions of excessive planting density, with temperature fluctuations, and also with a lack of calcium. It is characterized by the appearance of a plaque that obscures the upper side of the sheet plate. The second disease is in many ways similar to powdery mildew. It manifests itself in conditions of high temperature and humidity, however, plaque obscures the underside of the leaf with it. As a result, such a leaf darkens and deforms.

These diseases are very insidious, especially for beginners. Many of them ignore the resulting white coating and simply wipe it off with their finger. However, you should not do this, because the plaque returns again, starting to cover a large area of ​​the sheet plate, while noticeably increasing in size. As a result, those parts of the plant that have been affected will begin to wilt, turn yellow and die off. This is explained by the fact that the plaque covering the foliage and not only inhibits the process of photosynthesis, which is important for the plant, without which it is simply unable to maintain the green mass. New leaves rarely appear in diseased plants.

Both of these diseases are treated in the same way, but the process of plant healing itself is very difficult. First, it is necessary to eliminate all the affected areas of the bush, after which it is necessary to carry out a thorough treatment with Bordeaux liquid or a solution of copper oxychloride. At the same time, it is important to establish the irrigation regime, as well as eliminate the thickening of the plantings. Besides, in especially advanced cases, it is worth refraining from feeding, and also resorting to the help of such antifungal agents as Topaz or Skor.

If yellowish spots have formed on a pink shrub, then, as a rule, this indicates that the plant lacks potassium or iron - most often this problem appears in roses that grow on sandy or peaty soil. Moreover, in such cases, only the leaf begins to turn yellow, and its veins remain greenish. If this problem is not solved in time, then the young leaves will change their color to purple or reddish.

However, yellow spots do not always indicate that the plant lacks any elements. In some cases, this indicates the occurrence of such a viral disease as mosaic. It mainly affects the lower layers of the leaves, which is why they begin to fall off ahead of time, and the number of shoots is markedly reduced.

At the moment, there is no way to treat this disease, and therefore the plant will be best removed from the site and burned so that healthy plantings do not become infected. And in order to prevent the emergence of a viral mosaic, it is recommended to be more careful in the choice of seedlings, and before pruning, carry out the mandatory disinfection of garden accessories using a solution of potassium permanganate.

Reddish and burgundy specks on the leaves often appear on those pink shrubs that suffer from sunlight or that have been recently transplanted and have not yet had time to adapt to new conditions. Besides, such spots also indicate the occurrence of sunburn. In such cases, the plant must be shaded in some way or transplanted to a new place.

Red spots on the leaves also appear due to a lack of certain macronutrients in the soil, in particular, phosphorus, magnesium or nitrogen. In this case, the phosphorus deficiency can be replenished by adding superphosphate to the soil. If there is a lack of magnesium, it is worth adding ash to the soil, and if there is a lack of nitrogen, spray the green part of the plant with nitrogen-containing dressings.

However, in some cases, red spots indicate that the rose is sick with stem cancer, or an infectious burn. With this disease, brown spots with a red border are formed on the stem of the pink bush, which crack over time. Subsequently, with advanced cases, the pink twigs turn black. If you do not want to allow the death of the bush, then you should not bring it to this stage.

To save the plant, it is necessary to take timely measures. So, first, you need to eliminate the diseased areas of the plant, and treat the bush itself with fungicides or a 1% solution of copper sulfate. Note that this is not yet the final stage in the fight against the disease. Closer to autumn, the plant will need to be carefully examined for the presence of a disease, if necessary, eliminate suspicious leaves, and also carry out additional processing using fungicides.

Orange and red spots are usually caused by fungal diseases such as rust. Getting rid of this ailment is not so easy.

At first, due to this disease, yellow spots appear on the plant, which affect its stem part, leaves, and sometimes petals. Over time, sore areas crack. In advanced cases, the yellow color of the spots changes to burgundy or brown - this indicates that the disease has penetrated into plant tissues and is deeply entrenched there, and therefore it will most likely have to be dealt with next year.

By the autumn period, rust turns into black spot.At the same time, black spots appear on the leaves. The foliage itself then dries up and begins to fall off. At the final stage of the development of the disease, the plant stops circulating plant sap, and the shrub itself dies.

To eliminate this disease, you need to remove all the affected leaves, and also resort to processing with special means. For this, Topaz, Falcon and Bordeaux liquid are perfect.

Preventive measures, if not neglected, can avoid many problems and preserve the decorative effect of the rose bush.

• So, first of all, it is recommended to inspect the leaves of the plant on an ongoing basis, which will allow you to detect this or that problem at the first stages of its development and prevent its neglect.
• The plant must be provided with quality care. Regular pruning, high-quality and timely watering, making all the necessary fertilizing - all this allows you to keep the plant healthy and beautiful, and also supports its immunity. By the way, the rose's resistance to attacks from diseases and parasites, as well as frost, largely depends on the latter.
• Be sure to eliminate harmful insects, because they are often carriers of various kinds of infection, and also cause huge damage to landings.
• Do not forget about the elimination of plant residues at the end of the season, because fungal spores or larvae of parasites may well hibernate under them, which, under favorable conditions, will again begin to harm your plants.