How to protect roses from diseases in winter?

By: Merikheti
Published on: 17-Dec-2023

There is no need to tell how important a rose is for us. Rose is the best way to express thoughts. Roses of different colors are the best medium to express different feelings. It is important to take care that the roses remain healthy during the winter season. Rose plants face various challenges during the winter season, as cold and damp conditions create a favorable environment for various diseases. Successful management requires preventive measures as well as disease-specific targeted therapies. Let us know about some of the major diseases affecting roses in the winter season and their management strategies…


Powdery Mildew

 

Powdery mildew is a fungal disease that thrives in cool, dry conditions. This problem increases due to fluctuations in humidity levels in winter.

To manage powdery mildew, prune and burn infected plant parts during the dormant season. After that, this disease can be easily managed by dissolving soluble sulfur @ 2 grams per liter of water or neem oil based fungicide @ 5 ml per liter of water and spraying it twice at an interval of 10 days. Apart from this, ensure proper distance between plants for better air circulation.


2. Black Spots


   Black spot is a common disease of roses caused by the fungus Diplocarpon rosae. It thrives best in cool, moist conditions. Management strategies for this disease include:


Cleaning: Remove fallen leaves and debris to reduce overwintering spores. 


Fungicide: Spray by dissolving it in chlorothalonil @ 2 grams per liter or fungicide containing neem oil @ 5 ml per liter. Spray the second time after 10 days as per requirement.


Watering: Water the plants at the base to reduce leaf wetness.


3. Botrytis Blight


  Botrytis blight, caused by the fungus Botrytis cinerea, becomes even more problematic in the winter. Key management practices include..


Pruning: Pruning and removing dead or infected plant material.


Air Circulation: Improve air flow by pruning and proper spacing. 



Avoid overhead watering: Minimize watering of leaves to reduce the spread of disease.


              

      4. Winter Injury

 

          Cold temperatures can cause winter injury, affecting the overall health of the roses. Steps involved in management are 


Mulching: Apply a layer of mulch around the base of the rose.

 

Winterization: Gradually reduce watering in late fall to help the plant enter dormancy.


Selecting hardy varieties: Select rose varieties that are resistant to cold temperatures.


     5. Canker disease


        Canker diseases such as cercospora and Nectria canker can affect roses during the winter. Management includes..


Pruning : Remove infected branches by cutting below the affected area.


Fungicide: For prevention, spray copper based fungicide like Blitox 50@ dissolved in 3 grams per liter of water.


Hygiene: Clean pruning tools to prevent the spread of disease.


        6. Aphid Infestation 


          Aphids may still be active in winter, especially in mild climates. Control measures include..


Beneficial insects: Promote natural predators like ladybugs.


 Horticultural oil: Use neem oil or insecticide.


Regular Inspection: Monitor aphid colonies and take prompt action.


        

Summary


Successful management of winter rose diseases requires a multifaceted approach. From cultural practices like harvesting, pruning and proper spacing to targeted use of fungicides and insecticides, a comprehensive strategy is required. By understanding the specific challenges of winter and implementing proactive measures, gardeners can ensure that their roses continue to thrive even in the coldest months. Ultimately, a proactive and integrated approach to disease management in winter will help maintain the health and beauty of your rose garden. By implementing these strategies, you can enjoy vibrant and disease-free roses throughout the winter season.