Euonymus under attack

bajangirl

a patch of my Euonymus started going brown with no obvious cause. I was unable to go out into the garden for a few days  and then we had the 2 days of high temperatures. When I did the whole plant was dying and was covered in what looked like white fly but they all appeared to be dead as they did not move when disturbed. The stems are all covered in what looks like white flies and white powder and those with the brown leaves are also dead, the remaining stems haven't yet died.  Fortunately the other shrubs or other plants on either side were not affected.  The plant was grown from a cutting and was 30 years old, I have cut back all the affected stems quite hard removing all the leaves and it is looking pretty sorry for itself.  The stems are still alive so I hope it might recover. I would appreciate some advice as to what this might be, the likelihood of the plant recovering, and how best to treat the remaining stems .  photos attached.  thank you

GardenerSuze

@bajangirl It is Euonymous scale insect. It does seem to be coming more common. I have seen plants covered in it and yet they recover. 

Fairygirl

Aphids. The white debris is the skin casings of them. 
Cutting it all back will help, but you may have the same experience again, especially if you don't have suitable weather to help it thrive. They do like a good bit of moisture to do well, and reasonably retentive soil. You can help by adding some mulch - compost or similar, to help retain moisture, but do it after a good watering. 
This will be more common in future if you're in one of the very dry parts of the country, so autumn/winter/spring mulching will be beneficial - for many plants. Many birds love eating aphids, but sometimes there's a small imbalance, and some plants will struggle more than others. On the plus side, Euonymus are generally pretty tough 

bajangirl

Thank you, I have a heavy clay soil and it does get very dry.  I never rake up the fallen leaves from underneath it each year leaving them as a natural mulch as it seemed to shed them continuously throughout the year but did so when I cut it back thinking they might be infected with whatever had attacked it. I have metered water so in the garden only water plants in pots. I have another Euonymus gaiety on the other side of the garden where the soil is more improved and does better.  I will make sure I throw any suitable used water on both of them in future.