Wealden Times | WT188 | October 2017 | Kitchen & Bathroom supplement inside

Garden
Credit: FreeImages.com/Vera Berard
the leaf joins to the tree, at the leafstalk base, is a thin
layer called the ‘abscission layer’, which is the ‘valve’ that
ensures that production of chlorophyll stops and that any
remaining nutrients are drawn into the twigs of the tree.
This is a ‘process of subtraction’ as the tree’s metabolism
slows right down. So as the green pigment reduces, it leaves
behind yellow and orange pigments known as carotenoids
and xanthophylls. Reds are rather different and are caused
by anthocyanins which are pigments produced well after
the growing season ends. All completely fascinating stuff.
Human activity and resulting climate change is starting
to have an effect on autumn colour. For instance the overuse
of fertilisers leaves excess nitrogen in cultivated soils
resulting in nearby trees storing less sugar in their leaves
than they would in a pristine environment thus reducing
the strength of the bright autumn hues in their leaves before
winter sets in. As I mentioned when talking about the
local hornbeams losing their leaves so rapidly and before
they colour up fully, drought, too, affects autumn colour.
Conversely, excessive rainfall and cloud cover affects colour
photosynthesis, essential to produce red anthocyanins
which result in those fantastic autumn displays.
You’ll know that people flock to New England to see
the autumn fall colours. They’re known as ‘leaf peepers’
over there and they descend in great numbers in what is
normally a rather sleepy and rural part of the States. Here
we have the wonders of Sheffield Park, now a National Trust
property near Uckfield in East Sussex. Originally laid out
by Lancelot (Capability) Brown in the 18th century, many
of the trees have been planted for their autumn colour,
the most stunning of which in my mind are the black
tupelos or Nyssa sylvatica. One exceptional cultivar is N.
sylvatica ‘Sheffield Park’, a selection of the species raised
by the previous owner of Sheffield Park, Arthur Soames.
It bursts into glorious colour a week or two before other
tupelos. The colours reflected in the four lakes which form
the basis of this landscape are breathtakingly beautiful.
Trees for good autumn
colour might include:
Acer campestre (Field Maple)
Often a constituent part of native hedges, this
plant makes a medium sized tree with foliage
turning yellow with tinges of red in the autumn.
There are many lovely cultivars which are worth
a try including ‘Streetwise’ which is a Hilliers
selection and which combines an upright
habit with brilliant yellow autumn colour.
Cercidiphyllum japonicum (Katsura)
This tree has been thought to be related to the tulip
tree and has tiny red flowers which emerge just
as the new bronze pink leaves show. It is happiest
in a sheltered spot and has gentle autumn colours
in a soft yellow or smoky pink. These colours
combine with a pungent burnt sugary scent.
Liriodendron tulipifera
The tulip tree, in the Magnoliaceae family,
is a large tree with rather beautiful and very
curious foreshortened leaves which turn
a lovely clear yellow in the autumn.
Malus tschonoskii
A lot of the crab apples colour up well but this
is one of the best. A Japanese variety whose
leaves have rich tones of purple and scarlet,
yellow and orange in the autumn. With its
upright habit it’s a useful tree for quite confined
spaces and is a particularly strong grower.
Parrotia persica.
Actually this is more of a shrub than a tree and has
been on my wish list for years. Otherwise known as
Persian ironwood as it is native to Northern Iran,
Parrotia persica combines a gorgeous flaking bark,
not unlike that of a London plane, with a riot of
autumn colour and curious red flowers which come
straight off the stem rather like the Judas tree.
Sue Whigham can be contacted on
07810 457948 for gardening
advice and help in the sourcing
and supply of interesting
garden plants
Correction: In September’s
issue, in Sue Whigham’s article
‘Lavender’s Blue’ LIanata
should have read L. Ianata