On 28/11/2020 16:24, David wrote:
Autumn leaves are falling or have fallen.
As far as I know a lot of trees and shrubs take their cue from shortening
day lengths, and possibly also falling temperatures.

Those are the two normal triggers that plants use for going into
dormancy or for winter growers waking up.

However I am now seeing shrubs and trees coming into bud, and shooting as
well, which seems a bit early as we aren't even into Winter yet.

I don't have daffodils in flower yet but I have seen plum blossom full
out on a couple of trees as far north as Newcastle this week. Also there
are umbellifers in the hedgerow in spring flower again. In my own garden
the rosemary is flowering a second time this year.

Today we passed some daffodils coming into flower, which allegedly are
Spring flowering.

Mine are coming up but still a long way off flowering size. Strangely
the snowdrops seem to be late this year.

So what makes the flowers and trees think that it is Spring?
Is it daytime temperature?

Also, what are the implications for Spring flowering bulbs (and other
plants and trees) if they set off now when Winter is not yet upon us?

Most of them are from mountain climes and very cold hardy.

--
Regards,
Martin Brown