Sarah Raven bulbs are excellent but expensive (I shall still get some!) but on the other hand she gives a lot of free nformation in podcasts and videos. I was a bit releived to know that she too is having problems with peat free composts. Her theory is that they contain harmful chemicals from manures used to enrich them. Unfortunately she had no answers other than to test different ones. Expensive, time consuming and not very practical for most of us.
She also gave a tip about dealing with ants in pots which is to scatter crushed mint leaves on and around the pot - am trying this out and will report back!