Sharon, I'm sorry that none of my cohorts from the UK signed on, but I will try to extrapolate from my more general knowledge. I would plant seeds of Rudbeckia hirta, and R. fulgida, Coreopsis grandiflora, Gaillardia aristata, G, grandiflora, Leucanthemum [Chrysanthemum] maximum, Echinacea species and hybrids, Eustoma grandiflorum, Scabiosa caucasica, S. columbaria, perennial Gypsophila, and Dianthus. The young plants of these should all be able to take light frost in an unheated greenhouse, and should be ready to plant out next spring. There are probably dozens of others, but I don't have experience with them, so I can't honestly recommend them. Some of the gardeners from the UK may blow raspberries at some of my suggestions, so I would also repeat the question, in case this one simply fell through the cracks. Hope this helps at least some! : )

Thank you and sorry for very late reply x