Last year I sowed bellis perennis and planted them out in the garden in the Autumn ....none survived. I suspect problems with wet rather than cold here in Dorset... so this year I have planted them in a protected raised bed. They are blooming prolifically!! Please will somebody reassure me they should flower well when I plant them out in the garden next Spring.
You could try putting 2 or 3 inches of grit or pea shingle at the bottom of each planting hole if you suspect the wet caused them to die. They do require good drainage. If you have heavy clay soil even that may not be enough though and you may need to make a raised bed in the position you want them or grow them in pots.
Bellis often feature in the annual New Years Day flower count. They seem happy to bloom throughout the year if they're growing well.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.