Have you potted them on?
That will help but as we don't know what sort of winter we will get be prepared to insulate the pots as when we had the really cold spells a couple of years ago the pots in my cold gh froze solid and killed the roots whereas last year my pelargonium and osteospermum flowered in there all winter

Yes I have potted them on. When you say insulate them do you mean to place bubble wrap over them not to wrap them individual ( as I have around 150 including some cuttings ). Thanks

Whatever happens I hope you fair better than I did with T&M I bought los of 'plug' plants from them last Autumn and this spring, most of which did nothing or very little. Won't be using them again that's for sure. Good luck with yours.

Plug plants are a bit of a problem I find. If they are tiny, there are too many. The cost of re potting in time and new compost tends to outdo any advantage. Then you wonder where on earth they can go in the garden. If you plant them all they need watering and feeding. Never tried plug perennials but tiny plug perlargoniums drove me mad. I was too successful rearing them, then I had to attend to their needs! Some garden centres sell smaller pots of perenials......that's what I buy if obtainable.

I find they grow away very well and behave mostly as the older plant does over winter. Last year I had about 120 plugs and this year some I have had are - 36 lavender, 36 Petunias, 24 pansy/violas and 36 Penstemons all plug plants from this company and in over 200 plugs I lost 2 Penstemons.
Yes they are small but that is reflected in the costs and I love watching their progress.

Its the pots that need insulating from the cold, any way you like really but don't block the drainage holes or leave the pots covered for long, just for the worst of it.

I usually cluster pots together and then inulate around the outside, throwing bubble over at night if nessesary, as I said for me the problem was prolonged deep frost.....hope we don't get that again!