Frankly it depends on the plant.. which 'baby plants' are you referring to? Would never consider planting anything new out in autumn where we live.

yes well, Moongrower, I see you are from Scotland - me and my baby plants are soft southern Londoners! The ones I am pretty sure I have lost this winter are some lovely small Artemesias (brought from Beth Chatto's nursery, so had a good pedigree).

I too am in Scotland, but my sons in London have had their share of cold weather. I bought a lot of young plants cheaply in the Autumn. I have kept them in my unheated entrance hall and they are beginning to grow again. I will plant them out when the weather gets better. Snow and frost are a struggle for all young plants.

I'm Welsh, and we are tough :o)
But as for seedlings, I never plant anything out in the autumn. I usually sew sweet peas and sweet williams, wallflowers, bellis, to name a few. But I always keep them under cover until the spring - just incase.

Here in Surrey broad beans, peas, lettuce, onion sets and onion seed look as though they will not mature, i've sown more and will continue to do so, it's the hard frosts and disease that have been their downfall.

Hi Junie, Snow should be shaken off young trees and shrubs if possible. Although it looks light snow is incredibly heavy when it piles up on shrub branches. If it turns to ice, as it can do, it then attracts more and more water and weight resulting in irremediable damage.

I live in London, and I planted a load of different seeds in the Autumn, and was surprised that even though they spruted, the snow did not kill them, and they were as healthy as before the snow.

Snow can act as a blanket over flowers Alextb and acts as insulation to stop the frost getting at them. The difference between them and trees and shrubs is that the wind rocks the branches and the added weight can break them.

I suppose that is why they survived then.

It does depend what you're planting, as the others say - Artemisia may well keel over in a very bad winter, especially when young. It's unfortunate that we had an early and drastic onset of winter last year, even mature plants were badly affected by the sudden, early change from autumn to freezing cold. Most years, in London, I'd expect to get away with putting out baby plants in early September - but I wouldn't have risked small artemisias, nor other plants like Ceanothus and Nandina for instance - some things are better planted in Spring rather than autumn.
And Alextb, if your seeds are hardy annuals, they'll survive whatever the weather, unless they're caught by freezing when they first germinate.

nice to see some things don't change, Bamboo as usual giving me a really helpful opinion without making me feel as if I shouldn't be donning a pair of wellies! thanks to all of you.

Hmm, can't tell whether that's complimentary or not, lol!

it was a genuine compliment. I am sure a lot of GOYers are like me, not experts, not novices (I have been gardening for 40 years so have picked up a fair amount of general and practical knowledge) but sometimes we like to pick the brains of somebody who is obviously more dedicated and yet treats our trivial enquiries/comments with a bit of respect. (Sometimes when I read some of the questions and answers from other contributors I wonder why some new gardeners would ever come back to the site!) Sincerely, thanks

Well, that's very pleasing, thank you;-))

Here Here Junie.