Plant protection in winter?

Hello everyone. I have a list of plants which I have but i don't know if I should bring them into my greenhouse during winter as the past 3 years we have had heavy snow (enough to cancel on of our flights!) and we had temperatures as low as -13 last year. Anyway any info will be greatly received.
Everything is planted in pots. :P

Heather: Calluna Vulgaris
Perennial Liatris (Spicata White)
Perennial Anemone : Queen Charlotte
Hebe: Margret
Herbaceous Periennial: Silver Mist (Lavandula angustifolia)
Lupins in Pots
Chinese Latern Plant
Euphorbia: Baby Charm
Aster: Novi-Belgii Chatterbox
Celosia

 

Hi Kayleigh, most of what you list should be hardy enough and survuve the winter outdoors, with the exception of Celosia, which I believe is usually grown as an annual.

If we get a really cold temperatures then perhaps through some fleece of the Hebe just to make sure, otherwise it should be fine.

In general if you leave all the old top growth on perennials and cut back in the spring when new growth appears that will provide them with all the protection they need. Anything in pots just move them into a sheltered area, against the house wall for example.

With the Lavendar chop off the flowers when they finish and a little of the top growth, that way they will stay bushy and not get leggy and horrible to look at.

Hope this helps a little