A photograph of the problem would be very useful.

This sounds like an aphid infestation. Check underneath the leaves as this is where they will be hiding. The scales could be scale insect ( a sort of aphid too). These can be rubbed off with cotton wool dipped in meths.

If you can get imidacloprid (Provado, among others) in the granular form, applying that to the soil will also get rid of the scale, but it is slow-acting.