Primrose pests and diseases?

Can someone provide me with some information on this and cures? Thank you, I'm clueless on this!

 

quite a long list to be honest I will start off with two , vine weevil and slugs/snails , but saying that if growing in good conditions will romp away

Spruce

 

In my opinion that's their worst enemy, followed by grey mould/botrytis starting amongst the flowers and spreading to the rest of the plants.

And although not a pest/disease, prolonged periods of sub zero weather can devastate displays of primroses.

 

I have dug mine all out, more trouble than they are worth constant battle with caterpillars mainly, and the mould I did how ever have success with a few in the hanging baskets.