Blister mite?

Hi folks.  I have a Geum that I purchased from someone who grows their own plants from home a couple of streets away.  It's in a pot and hasn't flowered yet but I've noticed these pustules.  From a bit of research it looks like blister mite but I'd be very grateful for clarification and also what I can (organically) do about it and if it will harm the plant's development.  Many thanks for your help.