Despite the fall in temperature and the pretty severe gales we've had, oak
and beech trees around here still have many leaves on and plenty of them are
still fairly green. What about other parts of the country?
We still haven't had a frost here and today has got warmer but yes, it's
lashing with rain again!
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

"Sacha" wrote in message
.uk...
Despite the fall in temperature and the pretty severe gales we've had, oak
and beech trees around here still have many leaves on and plenty of them
are
still fairly green. What about other parts of the country?
We still haven't had a frost here and today has got warmer but yes, it's
lashing with rain again!
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

We've had only one morning when the windscreen of my car was frosted - and
then it was fairly half hearted.
Chris S in wet & windy Aberdeen

In article , Sacha
writes
Despite the fall in temperature and the pretty severe gales we've had, oak
and beech trees around here still have many leaves on and plenty of them are
still fairly green. What about other parts of the country?
We still haven't had a frost here and today has got warmer but yes, it's
lashing with rain again!

At Norwich, it is a very mild day, windy and wet. Last night was
dreadful, the roof creaked all night; I suppose it could be the vermin
but after a glass of wine, I can't tell the difference. The trees have
an enormous amount of greenery on them. However, I don't think it is
anything to do with weather - correct me if I am being ignorant but
don't trees drop their leaves when their produce abscic acid? I am not
sure whether it is really known whether this is related to the spectrum
of daylight or what - I expect Nick McLaren will know & I look forward
to the reply.

--
Judith Lea

In article , Sacha
writes
Despite the fall in temperature and the pretty severe gales we've had, oak
and beech trees around here still have many leaves on and plenty of them are
still fairly green. What about other parts of the country?
We still haven't had a frost here and today has got warmer but yes, it's
lashing with rain again!

At Norwich, it is a very mild day, windy and wet. Last night was
dreadful, the roof creaked all night; I suppose it could be the vermin
but after a glass of wine, I can't tell the difference. The trees have
an enormous amount of greenery on them. However, I don't think it is
anything to do with weather - correct me if I am being ignorant but
don't trees drop their leaves when their produce abscic acid? I am not
sure whether it is really known whether this is related to the spectrum
of daylight or what - I expect Nick McLaren will know & I look forward
to the reply.

--
Judith Lea

On 11/11/05 14:03, in article , "Judith
Lea" wrote:

In article , Sacha
writes
Despite the fall in temperature and the pretty severe gales we've had, oak
and beech trees around here still have many leaves on and plenty of them are
still fairly green. What about other parts of the country?
We still haven't had a frost here and today has got warmer but yes, it's
lashing with rain again!

At Norwich, it is a very mild day, windy and wet. Last night was
dreadful, the roof creaked all night; I suppose it could be the vermin
but after a glass of wine, I can't tell the difference.

Convivial bats in Norwich, eh? ;-)

The trees have
an enormous amount of greenery on them. However, I don't think it is
anything to do with weather - correct me if I am being ignorant but
don't trees drop their leaves when their produce abscic acid? I am not
sure whether it is really known whether this is related to the spectrum
of daylight or what - I expect Nick McLaren will know & I look forward
to the reply.

I'm sure Nick or David will be along to tell us - the autumn colour is
something to do with sugars, IIRC but I find it interesting that the ash
trees have lost their leaves, for example and the oaks and beeches are
holding on to them.
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

In article , Sacha
writes

I'm sure Nick or David will be along to tell us - the autumn colour is
something to do with sugars, IIRC but I find it interesting that the ash
trees have lost their leaves, for example and the oaks and beeches are
holding on to them.

there's a big difference in the times when trees shed their leaves -
whitebeam shed a long time ago, mulberry (which is always very late to
come into leaf) is still in full leaf - though yellow up here. The
sycamores opposite hold on to their leaves much longer than the horse
chestnuts.
--
Kay
"Do not insult the crocodile until you have crossed the river"

On 11/11/05 16:08, in article , "Kay"
wrote:

In article , Sacha
writes

I'm sure Nick or David will be along to tell us - the autumn colour is
something to do with sugars, IIRC but I find it interesting that the ash
trees have lost their leaves, for example and the oaks and beeches are
holding on to them.

there's a big difference in the times when trees shed their leaves -
whitebeam shed a long time ago, mulberry (which is always very late to
come into leaf) is still in full leaf - though yellow up here. The
sycamores opposite hold on to their leaves much longer than the horse
chestnuts.

Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase, BTW.
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

In article , Sacha
writes
On 11/11/05 16:08, in article , "Kay"
wrote:

In article , Sacha
writes

I'm sure Nick or David will be along to tell us - the autumn colour is
something to do with sugars, IIRC but I find it interesting that the ash
trees have lost their leaves, for example and the oaks and beeches are
holding on to them.

there's a big difference in the times when trees shed their leaves -
whitebeam shed a long time ago, mulberry (which is always very late to
come into leaf) is still in full leaf - though yellow up here. The
sycamores opposite hold on to their leaves much longer than the horse
chestnuts.

Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase, BTW.

I think the sequence is much the same, it's just so much later - this
year in particular (we've had no frost as yet, and still have healthy
nasturtiums - usually the first to go), but most of the recent winters
have been mild.
--
Kay
"Do not insult the crocodile until you have crossed the river"

On 11/11/05 17:56, in article , "Kay"
wrote:

In article , Sacha
writes
snip

Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase, BTW.

I think the sequence is much the same, it's just so much later - this
year in particular (we've had no frost as yet, and still have healthy
nasturtiums - usually the first to go), but most of the recent winters
have been mild.

Some pelargoniums are still flowering here and in other gardens, all sorts
of hanging basket/tub bits and pieces are growing strong and our Fuchsia
aencleandra hedges are going berserk. The tree ferns are still green and
one put out a new frond just a month or so ago and we've had to chop back
the Clematis rehederiana before it devours the chimneys. Even the Rosa
bracteata still has buds on it. I only moved to Devon 8 years ago and I
reckon I've seen changes in that time. I used to live in Jersey and I think
we're moving more in that direction in terms of flowering periods. I think
it would be interesting to see if plants that are evergreen in this part of
the country now remain evergreen in areas where they were deciduous - the C.
rehederiana I mention above makes me wonder. I think I remember Nick (?)
remarking upon it being evergreen here - perhaps it might be further north
and east now?
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

Got two massive London planes behind my house. Nearly all the leaves have fallen off now.

About 10% left id say. - In london area.

Kay wrote:

Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase, BTW.

I think the sequence is much the same, it's just so much later - this
year in particular (we've had no frost as yet, and still have healthy
nasturtiums - usually the first to go), but most of the recent winters
have been mild.

Indeed. I can't remember when we last had a frost before December, must be
early/mid 90's? What's your recollection Kay?

Jim

In article , Dave Poole
writes

snip
In most plants, chlorophyll completely masks other
pigments during active growth.

snip
With the reduction in nutrients, the chlorophyll breaks down and this
enables the previously masked carotene and/or anthocyanin pigments to
show through.

Good. That confirms what I deduced from observation, particularly with
maples - during the season the so-called red leaved maples are in fact
brown, which is a mixture of green and red, but go a much clearer red in
autumn as the green is removed. It can be seen very clearly as sweet
peppers ripen, from green through brown to red.

In some plants, the anthocyanin levels are very high as
the result of a secondary action of simple sugars in the presence of
sunlight (which is why fruits ripen red, orange or purple on the sunny
side). Plants with increased levels of anthocyanins in their leaves
turn red or reddish purple when the chlorophyll has broken down.

Are anthocyanins the same batch as you get in all those flowers which
are not entiely sure whether they are going to be pink or blue - like
lungwort, forget-me-not, cornflower or geranium?

Not
all tree carry anthocyanins though - the birches, beech and ash only
have carotins.

And therefore have an autumn colour of yellow?


They do here as well, - Aesculus are the first to colour up will start
even in August if the weather is very dry. Conversely the 'Turkey
Oak' - Quercus cerris holds its leaves until early December and
suddenly turns dark brown within a week, shedding everything a week
later.

the latest I've found is Swamp cypress, which here is still green and
hangs on to its leaves so late that I keep thinking it's going to stay
green all the year through.


--
Kay
"Do not insult the crocodile until you have crossed the river"

On 11/11/05 20:57, in article ,
"Dave Poole" wrote:

Sacha & Kay wrote:

Sacha:
I'm sure Nick or David will be along to tell us - the autumn colour is
something to do with sugars, IIRC but I find it interesting that the ash
trees have lost their leaves, for example and the oaks and beeches are
holding on to them.

As with anything to do with plants, the development of autumn colour
and leaf fall is complex, but here goes....

In plant leaf cells, chlorophyll molecules absorb blue and red light
so effectively that only green light is reflected (which is why leaves
are green) Also, molecules of carotin and anthocyanins are present
in varying quantities in the leaf and reflect yellow and red/purple
respectively. In most plants, chlorophyll completely masks other
pigments during active growth.

Chlorophyll is unstable and has to be replaced regularly throughout
the life of the leaf. In autumn, shorter days and cooler temperatures
trigger the formation of a water-proof, cork-like substance (suberin)
in a layer between the cells at the base of the leaf in the abscission
zone. This layer progressively reduces the flow of nutrients into the
leaf and chlorophyll production ceases. Later when the layer is
complete and the leaf falls, the suberin protects exposed cells
preventing invasion by harmful bacteria and fungi.

With the reduction in nutrients, the chlorophyll breaks down and this
enables the previously masked carotene and/or anthocyanin pigments to
show through. In some plants, the anthocyanin levels are very high as
the result of a secondary action of simple sugars in the presence of
sunlight (which is why fruits ripen red, orange or purple on the sunny
side). Plants with increased levels of anthocyanins in their leaves
turn red or reddish purple when the chlorophyll has broken down. Not
all tree carry anthocyanins though - the birches, beech and ash only
have carotins.

Rather like an artist mixing primary colours on his palette, the
presence of amounts of carotin, anthocyanins present affect the tone
and vibrancy of the autumnal colours. Dry, sunny weather causes
elevated sugar levels resulting in more anthocyanins in some trees and
richer autumn colours . I've left a lot out, but that just about
covers the basic sequence.

Kay:
there's a big difference in the times when trees shed their leaves -
whitebeam shed a long time ago, mulberry (which is always very late to
come into leaf) is still in full leaf - though yellow up here. The
sycamores opposite hold on to their leaves much longer than the horse
chestnuts.

They do here as well, - Aesculus are the first to colour up will start
even in August if the weather is very dry. Conversely the 'Turkey
Oak' - Quercus cerris holds its leaves until early December and
suddenly turns dark brown within a week, shedding everything a week
later.

Sacha:
Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase,

When I first came down here over 20 years ago, I noticed that autumn
was perhaps a week later than in the Midlands, where most leaves were
gone by mid-late October. Nowadays autumn seems to be where winter
first started and the trees are more likely to be stripped by severe
gales rather than conventional leaf fall. In 2003, the horse
chestnuts remained in leaf until November and many tree were carrying
their leaves without significant autumn colouring until late November.
This year seems to be more 'conventional' and most of the leaves that
haven't been stripped in recent gales, will have fallen by the end of
the month.

I can't bear to snip this! Wonderful, David, as always. Even in Jersey,
I remember we had the odd Guy Fawkes night that was bitterly cold and one or
two when we stood in hailstones in our field to watch the fireworks with our
cold and chattering guests! Mulled wine was very popular afterwards with
the parents and I always felt a bit sorry for the children who got apple
juice or something of that sort! We're going to have another go at a
fireworks party tomorrow night in the back field but there is no doubt that
it will not be a really cold evening. I feel the cold very much and can
honestly say that I haven't felt cold once this autumn.
--
Sacha
www.hillhousenursery.co.uk
South Devon
(remove the weeds to email me)

In article , Jim Jackson
writes
Kay wrote:

Yes but we can remember 5th November parties when all leaves had gone.
These days, they seem to hang on longer and longer! Our young mulberry tree
is in the same phase, BTW.

I think the sequence is much the same, it's just so much later - this
year in particular (we've had no frost as yet, and still have healthy
nasturtiums - usually the first to go), but most of the recent winters
have been mild.

Indeed. I can't remember when we last had a frost before December, must be
early/mid 90's? What's your recollection Kay?

I think we may be colder than you. We're higher up but we are in a frost
hollow.

From my gardening diary (I haven't a full record)
1999 - 10th October
2000 - 20th October, but very light, nothing killed (and we had snow
lying high ground on 30 Oct)
2001 - Nov 8th (following snow which did not settle)
--
Kay
"Do not insult the crocodile until you have crossed the river"

In message , Sacha
writes
Even in Jersey, I remember we had the odd Guy Fawkes night that was
bitterly cold and one or two when we stood in hailstones in our field
to watch the fireworks with our cold and chattering guests! Mulled
wine was very popular afterwards with the parents and I always felt a
bit sorry for the children who got apple juice or something of that
sort! We're going to have another go at a fireworks party tomorrow
night in the back field but there is no doubt that it will not be a
really cold evening. I feel the cold very much and can honestly say
that I haven't felt cold once this autumn.

Oxtail soup for all - with brandy for the grownups!

The oaks still have all their leaves, just about, the rambling rose is
flowering a bit again as is the ceanothus, and yesterday I saw the first
snowdrops poking up...


--
Klara, Gatwick basin