By Loobysue
United Kingdom 
My Pussy willow has developed this on lots of leave and stems, what is it? It is slightly powdery. Many thanks
19 Jun, 2014
Previous question
« each year i suffer blossom end rot with my tomatoes.i grow them in 10" pots...
Rust, a fungal infection.This plant is particularly susceptible, so you need a fungicide spray which treats for rust, spray all leaves, including the backs, till run off, and keep the spray handy for next year and treat at the first hint of it.
19 Jun, 2014