I got scale in my tiny garden and try as I might I lost plant after plant. It was terrible. The local herb garden could only suggest I scrub all the plants with Malathion on a toothbrush to try and get it off the stems. Repeated attempts failed and I ended up digging up clematis and cistus, bay, etc It does pay to keep a close eye on these woody plants. My garden was tiny so maybe hygiene had a part to play and also the plants were so close to each other which allowed the scale insects to spread so quickly