Hi, you can put hanging baskets out whenever the possibility of frost has passed in you area, but if they've been kept in a greenhouse, they will need to be hardened off before you put them out, Derek.

I'd wait another week or so, since we've been getting very chilly nights here in NY and it typically heads your way. Anything lower than 50F could be detrimental to plants but some are more tolerant than others.

Presumably they are currently sheltered, Pammie, in a greenhouse, for example? If so, leave the greenhouse open for a week or two (or put them in a cold frame) to gradually acclimatise them to colder air and then put them out if the forecast is favourable. Usually in this area the end of May should be safe.

I'm in Worcestershire but probably more sheltered than you Pammie, ( we've only had three frosts all in January), and I always put out tender plants Spring Bank Holiday week onwards.

Thanks