J52 - thank you for the good wishes. I noticed after my last post that Sultan Mix is actually Sweet Sultan Mix, so I think you are right, it is a relation of the sweet william. I am very tempted by cosmos as I love it, especially the big white one. I picked up a packet in Morrisons the other day but then put it back remembering my shortage of flower bed space but I think I will get it on my next supermarket trip.
Regarding dahlias, Monty Don showed what to do with them on Gardeners' World last Friday and said they are becoming quite popular again. You put the tuber cluster in a small amount of compost in a big pot and wait for it to sprout in the greenhouse. It can be planted out in the second half of May. I think I'll get one, or maybe two....or three.
Gardening is great, isn't it?