In my garden in Birmingham I wanted some poppies to grow, but they didn't seem to want to grow where I wanted so I tipped the seed into my wormery. I later distributed the worm compost around the garden and I found that the poppies just started growing where the positions were right for them. (i.e. in the recently disturbed soil on the veg plot!)
So I guess if you are struggling to grow any seeds and you have a wormery, chuck them in with your veg waste and they will grow in your garden in their favourite growing position!
I also use this "chuck it into the wormery method" if I think seeds are passed their best and won't sow. My original thinking was that it is vegetable material that the worms can make use of. I often find the seeds I have given up on germinating grow randomly around the garden.
I love plants self seeding in their chosen position - a little chaos in the garden of your favourite friends is a good thing in my book.