Rust on roses is a common fungal disease that manifests itself in the form of red spots on the leaves and stems. If you do not take action in time, the disease can weaken the plant and lead to its death. In this article,we will show you how to fix it and how to treat it for quick recovery.
Red spots on rose leaves
If you notice bright orange, red spots on your roses, this is an alarm signal – most likely, the plant is affected by rust. This fungal disease (caused by fungi of the genus Phragmidium) actively develops in conditions of high humidity and insufficient air circulation. The first symptoms usually appear in spring or early summer: small yellowish-red spots form on the upper side of the leaves, which increase in size over time. If you turn the leaf over, on the reverse side you can see pustules – convex formations filled with fungal spores. As the disease progresses, the spots darken, the leaves begin to turn yellow, curl and fall off, and the shoots become deformed.
Red spots not only spoil the appearance of roses, but also weaken them:
- the plant spends its energy fighting the infection;
- worse blooms;
- becomes vulnerable to other diseases and pests.
If you do not take action, the fungus can spread to neighboring bushes and lead to the death of the rose. Especially quickly the disease spreads in rainy weather or with excessive watering on the leaves.
It is important not to confuse rust with other diseases or physiological damage. For example, sunburn can also leave red spots, but they do not have the characteristic pustules on the back of the leaf. Potassium deficiency sometimes causes yellowing of the edges of the leaves, but without red spots. If you see orange-rusty spots with a powdery coating, this is a clear sign of a fungal infection that requires immediate treatment.
The sooner you start fighting rust, the easier it will be to save the plant. At the initial stage, it is enough to remove the affected leaves and treat the rose with folk remedies. But if the disease has already covered most of the bush, stronger fungicides will be required.
How to treat roses from rust
One of the most effective methods of treatment is biological. If you do not know how to treat roses from rust, use formulations based on beneficial microorganisms that fight pathogenic microflora.
Start treatment immediately after the first signs of the disease are detected. Carry out regular preventive spraying during the period of active plant growth. Make sure that the treated surfaces are well moistened with the product, repeating the procedure after rain or strong wind.
Effective biofungicides:
Fitosporin-M
Contains a live culture of Bacillus subtilis bacteria that inhibit the growth of pathogenic microorganisms. Phytosporin is safe for humans, animals and bees.
- Application: Concentration: 5 grams of the drug per 10 liters of water.
- Processing frequency: every 7-10 days.
Alirin-B
Active ingredient-spores of the Bacillus subtilis fungus strain. The drug actively suppresses the development of pathogenic microflora, causing the death of spores of the pathogen.
- Application: Concentration: 2 tablets per 1 liter of water.
- Frequency: three treatments with an interval of one week.
Gamair
Another product based on live bacteria Bacillus subtilis and other strains. Gamair effectively protects and eliminates rust on roses.
- Application: Concentration: one tablet per half-liter of water.
- Processing interval: every week.
When deciding how to treat roses from rust, experts recommend combining biological preparations together with agrotechnical measures (watering, airing, removing infected leaves) to ensure maximum protection of your roses.
Folk remedies for plant rust
If you do not know how to cure red spots, use folk methods.
Soda solution
One of the most popular means is soda solution. For its preparation, take 1 tablespoon of baking soda, 1 teaspoon of liquid soap ( household or tar) and dissolve in 1 liter of warm water. Soap plays an important role here – it helps the solution stick better to the leaves. This composition of the plant is sprayed every 5-7 days, necessarily treating not only the upper, but also the lower side of the leaves, where the fungal spores are usually located.
Garlic infusion
No less effective is garlic infusion, which has pronounced fungicidal properties. How to cure a fungal disease with it? To prepare the composition, take 3-4 large cloves of garlic, chop and pour 1 liter of hot water (about 60°C). Insist the mixture for at least a day, then filter and use for spraying. Garlic infusion is best used in cool weather, as it quickly loses its properties in the sun.
Decoction of horsetail
Well eliminates red spots decoction of horsetail. This plant contains silicic acid, which strengthens the tissues of roses and makes them resistant to fungal diseases. To prepare the broth, take 100 grams of dry horsetail or 1 kg of fresh, pour 10 liters of water and insist for a day. Then the infusion is boiled for 1-2 hours, cooled and filtered. Before use, dilute with water in a ratio of 1: 5.
Wood ash
How else can I treat roses? Wood ash is another proven remedy. It not only fights the fungus, but also serves as an excellent potassium top dressing. For the solution, take 1 cup of ash per 2 liters of water, insist 2-3 days, stirring occasionally. Then add 1 tablespoon of liquid soap, filter and spray the plants. The sediment can be poured under the root – this will serve as an additional top dressing.
Milk Whey
Whey or kefir, diluted with water in a ratio of 1: 10, creates an acidic environment on the leaves, because of which the rust on the roses gradually disappears. Milk bacteria also compete with pathogens. This solution can be applied every 3-5 days.
It is important to remember that all folk remedies require regular and repeated use. Unlike chemicals, they do not accumulate in plant tissues and are easily washed away by rain. Therefore, the treatment should be repeated every 5-7 days, and after rain – be sure to resume. For better adhesion to any solutions, it is recommended to add soap (1 teaspoon per 1 liter) or a few drops of vegetable oil.
When working with folk remedies, do not forget that natural compounds can cause leaf burns in bright sun. Therefore, it is better to carry out processing in cloudy weather or in the evening hours. If after the first application, the rust on the roses has not passed, its signs have not become less, perhaps the disease has gone too far and it is worth switching to stronger drugs.
Fungicides for the treatment of roses
Fungicides for the treatment of roses are divided into three main groups:
- Contact (protective)devices
- They only work on the surface of the plant
- Do not penetrate into tissues
- Effective for prevention and in the early stages of the disease
- Examples: Bordeaux blend, Abiga-Pic, HOM
- Systemic (therapeutic)
- They penetrate the vascular system of the plant
- They operate from within
- They can stop an already developing disease
- Examples: Topaz, Skor, Fundazol
- Combined services
- They combine the properties of contact and systemic drugs
- They are most effective in cases of severe infection
- Examples: Ridomil Gold, Ordan
For prevention, you should use contact or biological drugs. Use systemic fungicides at the first sign of illness. In advanced cases, use combination medications. Alternate medications with different active ingredients.
TOP 5: effective fungicides for the treatment of roses
1. Topaz (penconazole)
- Type: System
- Effective against: rust, powdery mildew, spots
- Dosage: 2 ml per 5 liters of water
- Treatment frequency: every 10-14 days
- Features: Fast-acting, can be used at low temperatures.
2. Skor (diphenoconazole)
- Type: System
- Effective against: rust, black spot, powdery mildew
- Dosage: 2 ml per 10 liters of water
- Frequency of treatments: 2-3 times with an interval of 7-10 days
- Features: it has a prolonged effect (up to 3 weeks).
3. Bordeaux blend
- Type: Pin
- Effective against: rust, anthracnose, bacteriosis
- Dosage: 100 g of copper sulfate + 100 g of lime per 10 liters of water
- Frequency of treatments: 1 time in 2 weeks
- Features: Creates a protective film on the leaves.
4. Fundazole (benomil)
- Type: System
- Effective against: a wide range of fungal diseases
- Dosage: 10 g per 10 liters of water
- Frequency of treatments: no more than 2 times per season
- Features: it has both fungicidal and acaricidal action.
5. Ridomil Gold (mefenoxam + mancozeb)
- Type: Combined
- Effective against: complex fungal infections
- Dosage: 25 g per 10 liters of water
- Treatment frequency: every 10-14 days
- Features: contains two active ingredients with different mechanisms of action.
Prevention of fungal diseases of roses
Prevention of fungal diseases requires a systematic approach, starting with the correct choice of landing site. A sunny area with good air circulation is ideal, where the roses will receive at least 6 hours of direct sunlight daily. When planting, be sure to observe the recommended distances between bushes-50-70 cm for hybrid tea varieties and 1-1. 5 meters for climbing varieties. This will ensure adequate ventilation and prevent stagnation of moisture, which creates favorable conditions for the appearance of rose rust.
Pay special attention to the watering regime. Water the bushes at the root, preferably in the morning hours, so that the foliage has time to dry out before the evening coolness. The frequency of watering depends on weather conditions – on average 1-2 times a week, and it is important to avoid both waterlogging and drying out of the soil. To maintain an optimal level of humidity and prevent spores of fungi from splashing from the ground to the leaves, be sure to mulch the root zone with a layer of bark or compost 5-7 cm thick.
Regular sanitary pruning should be carried out periodically. Systematically remove weak, damaged and thickening bush shoots, as well as withered flowers. Make all cuts at a 45-degree angle with a sharp, disinfected pruner. In the spring, before budding, carry out the main forming pruning, in the fall-preparatory for wintering. After working with each bush, be sure to disinfect the tool with an alcohol solution or potassium permanganate.
The correct scheme of top dressing strengthens the immunity of plants. In the spring, apply nitrogen fertilizers to stimulate growth, in the summer switch to potassium-phosphorus complexes that promote high-quality flowering and increase resistance to diseases. In the fall, eliminate nitrogen, focusing on potash fertilizers to prepare for winter. Remember that overfed roses are just as vulnerable to fungi as those weakened by lack of nutrition.
Start preventive treatments in early spring by spraying 3% Bordeaux liquid on dormant buds. During the growing season, switch to biologics (Fitosporin-M) or systemic fungicides (Topaz, Skor), alternating them to prevent resistance. Especially important are treatments before and after flowering, as well as in the fall before covering for the winter with a 3% solution of iron sulfate. Between chemical treatments, you can use folk remedies – ash infusion, whey or garlic extract.
Now you know how to cure rust on roses and prevent its appearance. The main thing is to notice red spots in time and start treatment. Use fungicides to treat roses or folk remedies, and do not forget about prevention. Healthy roses will delight you with a lush bloom!