It's a good time for planting bare-rooted plants. Plants in pots can be planted out any time of year. Of course it all depends on species. There should be a label on them if you got them from a garden centre giving planting info. If a plant comes from a warm climate it shouldn't be planted out this time of year. Plants from more northerly climates should be ok.
The Mooney show spoke of -8 frosts tonight, said need to pot up any fushias or germaniums and place indoors/greenhouse, protect bay tree stem with pipe insulation.....