It’s the weekend, and you have just been making the rounds on your garden or your farm when you lay your gaze on a rose with black spots. What a disaster! Depending on what you know about black spots on roses, you can either choose to ignore this and continue your stroll because you don’t know what it means or, stop whatever you are up to and focus on solving the dilemma at hand. In this guide, you will learn how to get rid of black spots on roses and what causes black spot on roses.
Black spots on roses are a common rose disease caused by a fungus called diplocarpon rosae. It attacks the roses and can lead to the plant’s defoliation. They are not the only diseases your rose plant is vulnerable to.
Common Rose Plant Diseases
1. Powdery mildew: This type of disease is identified by the appearance of a white powdery substance on the rose plant’s leaves and stems. It gives the rose plant a wrinkled appearance and, if left untreated, can make kill the plant.
2. Cankers: Notice any brown or grey areas on the stem of your plant? That can be a sign of rose cankers. To control this disease, prune out the infected parts with disinfectant-cleaned pruners and apply fungicides.
3. Rust: As the name signifies, this is indicated by rust-coloured patches on the undersides of the leaves on your rose plant.
4. Botrytis Blight: This is often identified by the growth of a grey mould on the body of the rose plant. It causes rose buds not to open. Another symptom is light-coloured spots with red coloured outer rings. It can be gotten rid of by using copper fungicides.
5. For a complete listing of common rose diseases, click here.
When left unchecked, this fungus will rage, infecting the whole plant and causing it to shed its leaves.
An early symptom of this disease is that a purple spot appears on the leaves of the plant. In addition, The areas around the infected parts turn green or any other sufficiently pale colour. Lesions also appear on the affected rose plant’s stems.
What causes this disease?
Many factors could bring on this disease, but moist conditions around your rose are more likely to cause it. Hence, if your rose grows in any damp place, then there’s a real-life possibility that it is susceptible to this fungus. The best way to push and fight off this disease is by prevention and treatment.
Moreover, there are measures you can take to prevent the likelihood of this fungus attacking your rose plants, and those measures typically include some garden hygiene and regular spraying.
You should take care of your garden by planting roses some metres apart from each other to give them room to breathe. More so, you should plant them in a good location where they will be getting enough sunlight and good airflow. Indeed, The importance of adequate sunlight and proper ventilation to rose plants cannot be overemphasized. They are essential to the healthy growth and germination of your plants.
Another hygienic step to take to prevent the occurrence of black spots on roses is to remove leaf litters as soon as possible. Leaf litter can be a very potent breeding ground for germs and fungi, so it is vital to remove them as soon as they drop to have a much cleaner environment.
Also, if there any dead leaves or diseased stems on your plant, you should remove them as fast as you can or prune them in cases of diseased limbs. This will allow new, healthy branches to grow. The fungus can remain on dead leaves or stems, and since they are either airborne or waterborne, they can reinfect the plant at will. So, it is essential that you correctly dispose of the pruned leaves and stems to prevent this from happening.
Taking all these hygienic measures is not always enough; you should combine them with traditional fungicides.
In conclusion of ways to get rid of black spots, create a schedule for spraying fungicides on the plants. Fungicides that work contain a mixture of tebuconazole, tebuconazole with trifloxystrobin, and triticonazol. Either of these compounds or combinations are active agents in preventing black spots on roses.
So your rose plant already has black spots despite your best efforts to prevent this menace, and you are wondering how to deal with this. Relax, it is not the end of the world. With the right treatment, your rose will be looking healthy and be standing firm in no distant time.
The right treatment, in this context, involves certain things:
1. Pruning the infected parts: Firstly, remove the infected leaves. Ignoring them is an invitation to the fungi to continue spreading. Remove them, then gather all the ones that fell and get rid of them. It would help if you did not try using these leaves as compost; We suggest incinerating them or doing something more drastic. Here’s a guide on how to prune roses.
2. Change your watering cycle: Secondly, try timing your watering cycle to coincide with the time frame just before the sun comes out. Ideally, this should be in the morning, and this may vary by season. This timing is to make sure the water dries off well and does not form a puddle which is a breeding ground for more fungi.
3. Spraying: In addition to the sprays used to prevent their very occurrence, you should look for other equally effective sprays and use them on the infected plants. Spraying them with effective fungicides is a quicker way to make the disease die off.
4. Effective Mulching: Mulching refers to the practice of heaping compost/soil around the roots of a plant. You should make sure your mulch layer is up to 2 inches or more in height and you should add at least another inch every year as this will help prevent the growth and spread of fungi through the mulch. Also, try turning over your mulch once a while to enable greater aeration and expose hidden fungus to the sun to die off.
5. Planting more resistant varieties: Some rose plants are bred to be more resistant to such common diseases, including black spots. These are the best type of roses to plant as they are less stressful to look after while producing the same type of rose. Some of the resistant varieties include the Rosa Mortima Sackler, the Rosa Roseraie L’hay, and the Rosa Boscobel.
This is pretty much all you need to get rid of black spots on roses and protect your rose garden from degradation and infection. If you planted other crops or plants, you should isolate them again from the infected roses and apply fungicides to them; the black spot infection can also spread to other plants.
Other guides have been prepared for other things you will need in your garden; check them out:
- How to choose the best bird tables
2. Choosing the best lawn spreaders
3. Getting the best hedgehog house
4. Guide on the best moss killers
Frequently Asked Questions
Is there a homemade remedy for black spots?
Yes, but we won’t advise it as the chances of you producing an exact formula that will treat the black spots without damaging your plant is very low. As much as possible, we advise using industry-approved fungicides to treat this menace.
Does neem oil kill the fungi causing black spots?
Yes, to an extent. Neem oil is effective against a wide array of fungi infections that plague the common rose plants, and it is also effective against beetles and other pests. Neem oil is a type of vegetable oil and is produced from the neem plant. Before using this solution, we suggest consulting relevant authorities as it has been banned in parts of the UK.
Can roses recover fully from the black spot disease?
Yes, after the above treatments have been applied. The fungus will die off but be warned, the black spots will remain on the plan. We advise removing such leaves to restore the rose’s natural aesthetic beauty.
Your roses getting black spot diseases is not the end of the world; with the correct treatments, the damage caused can be treated and corrected, and precautions are taken to prevent such an incident from repeating next time.