Hardening off?

So I get the concept and I know how to do it. Just unsure on all the situations when I need to do it. Seedlings grown indoors/under glass, yes. But what about these 2 situations?
Clematis bought from shop where it was kept inside? No idea how it was kept before then.
Plug plants, one put outside straight away, doing fine. Others in pots in greenhouse for about 3 weeks, now I’d like to put them outside.
So I guess, both hardy plants that've spent some time indoors. Do they need hardening off, or can they go straight out?
Thanks

 

Well hardening off is something that should always be considered.
However, we are now reaching a time when greenhouses are practically open all day, as the weather is warm.
It is pleasant outside much of the time now, so yes be a bit careful about acclimatization but it is slightly less important as we move into summer.

 

Hi,

Probably the biggest danger this time of year is moving shop indoor or greenhouse plants outside where they can catch too much sunshine which can scorch any tender plant, so always place any such tender plants into semi shade to start with.

 

Most plants grown indoors need to be acclimatised to the world outside before planting out and regardless of the time of year I think. A sheltered corner out of direct sun for example would suffice right now

 

Thanks Just on day 6 of hardening off some seedlings grown indoors. They had to stay out for a night eventually, I just hadn’t planned on it being last night-ooops!​