By Marty777
Essex,
United Kingdom 
Hi, please can someone tell me why my hydrangea (which is growing to a substantial size) has suddenly developed white which looks like very small dots of cotton wool/polystyrene on the leaves? sounds weird but this has just started happening.
9 Jul, 2010
this is either wooly aphid or scale insect. A soap solution sprayed on the plant will help get rid of them or use a systemic insecticide to control them.
9 Jul, 2010