I can think of two possibilities:
Woolly aphids http://www.rhs.org.uk/advice/profile?pid=724
one of the scale insects http://www.rhs.org.uk/advice/profile?PID=557
Do either of those look right?
Thanks a lot for your reply.
I have some pictures, but can't upload them?
It looks more like the scale insects, but could it be spider mites as well?
the strange thing is, I only see the cotton ball like stuff, but not the actual crawling pests.
To upload pics on here you need to click on the green tree icon on the toolbar above where you type your post, and follow the instructions. Sadly it doesn't work for phones .... yet!
There is no reason why your plants should only have one problem - such are the pleasures of gardening!!!
I've never had a problem with spider mites and usually they're only a real nuisance in greenhouses or on indoor plants, but we've had a mild winter and now a warm dry spell so they could well be affecting outdoor plants.
I saw them now - yes it looks like scales!
What can I do best?
I would say the plants are not heavily infested yet.
Taking out and replanting is not possible as it is our cork screw willow and three other large shrubs are affected!
I've just had that stuff on my potted, 10 year old, Acer. I had it 2 years ago and sprayed it with Provado and that got rid of it but this year the insect has been worse. As before, a good spray seemed to work BUT now the acer looks as if it is dying! A lot of leaves are going brown. So be careful what you use on which plants. Mags
More info here http://www.gardenforumhorticulture.co.uk/pestwatch/scale-insect.htm
I've always been able to remove them by hand, sort of scraping and scrubbing, but I've never had to deal with a bad infestation. Once you've had it you keep your eyes open for it.
We will scrap them off and also use Bayer Provado!
I am worried about our cork screw willow tree
I hate using Provado, as I try to be organic, but iy does do the job !
I had a really bad scale infestation on one of my hydrangreas .... I just rubbed them off and over a period of weeks they disappeared.
I took all the scales off and after all there weren't that many as far as I could see.
However our cork screw willow tree still looks very sad and I believe it is affected by something else!
It hardly has any leaves this year, only at the top! And the twigs are dying back turning brown/black in colour!
Does anyone know what this is and what I can do about it.
I don't want to loose it, I love this tree