As summer lingers, our trees are in a state of quiet transition. The vibrant flowers of spring have faded, yet the rich colours of autumn have yet to arrive. Now is the perfect time to identify trees by their leaves alone, from the glossy sheen of a beech to the first shrivelled signs of a hot summer on a sycamore. In the woods, a new season is quietly beginning as acorns and cones start to fall, and colourful fruits and berries emerge. Look closely, and you might spot the spectacular crimson fruits of the Stag’s horn sumac or the cascading yellow flowers of the Mount Etna broom.
Return on August 25th for the full article!
Article
Trees
August is a month when trees are still in full leaf, tree flowers are being seen less and less but seeds and fruit more and more. It seems as if there is a pause between the flowering period of trees before they start colouring up again in the autumn. If the summer has been a hot one, many trees such as sycamore, lime and hornbeams look stressed by now, some looking dry and shrivelled. It is however one of the best months to identify trees by their leaves alone. Some leaves develop an added gloss or bloom before they colour and fall.
Trees such as beech and birch have shallow rooting systems which means they are prone to losing their leaves in dry spells. In such conditions, bare shoots and discoloured patches on branches may also be noticed. Another feature of the month is the occasional fresh or lammas growth seen on some trees and free suckering seen near others.
In woods, which are darker than usual because of thick leaf canopies, leaves are now starting to be noticed on the woodland floor. In conifer woods it is cones that are starting to fall and in oak woods, acorns. Keys are developing on sycamores and limes, berries on yew trees and long pods on Indian bean trees. More spectacular are the deep crimson fruits on Stag’s horn sumac and the equally striking coloured fruits on the Japanese dogwood Cornus kousa. The latter tree is not common but can be found at Wisley. Best of all for Londoners are mulberries, which ripen towards the end of the month. They tend to be collected quickly to be eaten. They are not found on sale as the fruit tends to bleed the moment it is touched.
One of the most noticed trees now is the Mount Etna broom Genista aetnensis which produces cascades of yellow pea flowers on virtually leafless branches. It comes from Sicily as its name suggests, but unlike other brooms it can grow to the size of a small tree. Four metre high specimens are often seen in front gardens but it has been known to reach eighteen metres elsewhere in Britain. Other rare trees that provide a show this month include Eucryphia, Oxydendron, Albizia, Maackia amurensis as well as the increasingly popular Chinese privet Ligustrum lucidum. There are also a number of summer flowering magnolias and Eucalypts.
Eucryphias are famous for their towers of flowers in August but these are rarely seen in London, possibly due to their intolerance of lime. Oxydendron, the sorrel tree, gets its name from the taste of its leaves which are acidic like wild sorrel. Its small fragrant flowers can be seen at Eltham palace. A fine specimen of the Chinese Yellowood Maakia amurensis can be seen near the Observatory in Greenwich park. Tufts of white and yellow flowers are also to be seen on Eucalyptus spp. The snow gum E. niphophila is one often seen in gardens. The group includes gums, peppermints and sallys. The cider gum E. gunnii is one species that often finds its way into gardens even though it is renowned for the speed at which it grows. Its flowers have hinged lids which open to allow insects in to pollinate.
Rarer eucalypts can be found at Hampton Court (Mount Wellington peppermint E. coccifera), Syon park (Shining gum E. nitens), Ruskin park (Silver gum E. cordata) and Dulwich park (Tasmanian blue gum E. globulus). Although thankfully not hardy, the last species can grow an astonishing five metres a year. They are all famous for their eucalyptus oil which, in the case of the Tasmanian blue gum, is almost numbing in its strength.
As London gets warmer we are also likely to see many more silk trees Albizia julibrissia. These are Asian trees famous for their large pom-pom shaped tufts of long silky rose-pink threads. They are every inch a tropical-looking tree but as yet they tend to look a little unhappy in London. With a little more warmth they are known to grow twelve metres high and develop widespread crowns.
