Question
Hi Lynette
I live in Namibia (South West Africa).  We currently are in our winter months where temperatures range from 23 degrees C (daytime) and nighttime temperatures from 10 degrees C to 3 degrees Celsius.  
My roses have just stopped blooming 2 weeks ago!  They are small rose bushes, colours red and pink roses.  
However they have developed yellow leaves and I am not sure whether they have a virus or not.  Am new to rose growing.  If I look at pictures of Rose mosaic virus it does not look like the pictures.  The whole leaf is yellow and some leaves just at the tip of the leaf.  The rest of the plant is a healthy green.  
They are small plants approximate. 1m in height.
Can you help please?
I have just started spraying them with Rosecare3 an insecticide plus a systematic fungicide and they suggest spraying every 7 days until whatever disease is no longer present.
They get morning sun but afternoon shade in winter.  I water them every 2-3 days.  Maybe too much?
Kind regards


Answer
From your description of the roses I am positive that they do not have a virus. Any type of virus looks like someone has dribble bright yellow paint on the leaves. Viruses are not a solid yellow colour. Yellow leaves on a rose do not necessary mean anything is wrong with them. However some roses do re-act to a systemic spray, especially if the weather is changing as both will cause the roots to shut down. Your roses do not have any disease so a spray is not necessary.  At some point in time they have to have a rest. Temperatures like you have said are happening, will always put roses under stress and they will start to pull down their sap to go dormant in the winter type weather. I wouldn't worry about them but keep watering to make the soil damp but not really wet. Don't give anymore fertilizer as you don't want them to keep growing for at least a month or as long as your winter lasts. When your weather evens out near the spring, the roses will start to grow back again and flower for you.