They are much too small to plant out, Sheila. keep them in the frame over winter.

Thanks Bulba - is it because they need more root to establish? (The Nigella are quite well developed, as are some Aquilegia not in my photo, about 4" high - maybe they'd be large enough??)

It is about to get quite cold and wintery Sheila. Your plants, still in the cold (but warm) greenhouse still need to be hardened off. I would still keep them in a frame over winter; keep the top open as much as possible for ventilation but close it down when heavy rain, snow, hard frost etc are forecast.
At the moment I am only planting out mature plants (two or three years old) and plants that I am moving or dividing.

Thanks so much Bulbaholic . . . really useful.