As April unfolds, London’s trees burst into life, painting the city in vibrant hues of green, pink, and bronze. From the iconic Kanzan cherries to the delicate tulip trees near Kensington Palace, the capital is a living tapestry of spring foliage and blossoms. Did you know London’s limes inspired the name of botanist Carl Linnaeus, or that plane trees hide their buds in clever ways? Join us on 15 April as we explore the fascinating stories behind London’s trees, their seasonal transformations, and the hidden beauty of their buds and blooms. Don’t miss this celebration of nature’s artistry!
Article
Tree Buds and Flowers
At the beginning of April many cherries maples and other trees are producing red or bronze-coloured leaves which will soon change into many different shades of green. The first poplar leaves are often a shiny tan or even bronze colour. In gardens new Photinia leaves stand out, being a bright shiny red. As the flowers of the early myrobalan plums fall, their deepest purple leaves emerge. Other trees bursting bud at this time are bird’s eye cherry Prunus padus, snowy mespil Amelanchier laevis, pear trees, whitebeams, more Japanese maples and the first lime-green flowers on Norway maples. Catkins are lengthening on birch trees but the buds on beech, oak and ash still remain resolutely closed.
In the second week of April usually the early trees to burst bud have now opened their leaves fully. Lime trees are now producing their downward pointing clusters of lime green leaves. This moment in the spring sees these trees at their best. The common lime Tilia x vulgaris seen all over London, is believed to be a hybrid of our two native limes, the small-leaved lime T. cordata and the large-leaved lime T. platyphyllos. Its appearance was first noticed in the seventeenth century. There are still some venerable coppiced limes around, some of which are thought to be older than ancient yews.
Lime wood was famously used by the seventeenth century wood carver Grinling Gibbons. As a boy living in Ludgate Hill he is said to have carved pots of flowers so delicately they shook as carriages passed by. Later lime wood went on to be used to build Mosquito fighter planes. The great botanist Carl Linnaeus was named after a lime tree, which grew in his family’s back garden, many Swedish families possessing no surnames at the time. In contrast to the lime’s downward pointing leaves, those of whitebeams all point upwards. They also stand out now, having a felty appearance and being that unusual pale powdered sage green colour. Norway maples Acer platanoides also stand out, due to their abundance and their vivid lime green flowers, which have yet to be joined by any leaves. Ash trees largely go unnoticed, although they are covered in tiny purple petalless flowers, with no leaves yet apparent.
Other trees bursting bud include the Caucasian wingnut, Lombardy poplars and various rowans. Caucasian wingnuts Pterocarya fraxinifolia, like elderberries, have no protective scales around their developing leaves. Their tiny, miniature leaves seemingly unaffected by frost and wind, although being held close to the branches this offering them some protection. Alder trees are also now changing colour due to their new cones, which are a rich red. They have unusual stalked buds, as do Persian ironwoods and some wych hazels. Many catkins are now becoming noticeably longer, particularly those on various white birches which are so popularly planted in London’s gardens.
The third week of April usually sees the deep pink-petalled masses of Kanzan cherries all over the capital. The early cherries have been generally softer pinks and whites; now London is suddenly thrown into peak cherry and crab apple time. Their arrival usually coincides with candles on horse chestnuts. Some late budders, such as London plane, Acacia, tulip tree, hazel and stag’s horn sumac all now start to open. Of these, the tulip tree Liriodendron tulipifera is worth examining as the folded leaves seem to unfurl from a small green purse. An avenue of tulip trees leads up to Kensington Palace. The buds on plane trees are also unusual as they remain hidden, protected by the swollen bases of their petioles, only becoming visible when the leaves fall.
The end of April usually sees the last of any bare trees in parks and on the open landscape. Trees such as oak, beech, weeping ash, walnut, tree of heaven, Pride of India, mulberry and the Caucasian elm all start to green. The buds of walnuts are unusual as there may be more than one in each leaf axil. In Caucasian wingnuts there may even be a small row. The buds of the weeping ash, instead of being a sooty black like most other ash trees, are a mocha brown. The leaves of Caucasian wingnuts look enormous as they unfurl, as do the felty white leaves of some whitebeams e.g. Sorbus aria ‘Majestica’ whose leaves may eventually reach fifteen centimetres in length. There is a group of the latter tree on Primrose Hill.
Another interesting tree coming into flower now is the handkerchief tree Davidia involucrata which, along with its green leaves, produces white ones that are its flowers. Sycamores are now in full leaf, with a variety of strong colours to be seen among its many cultivars. Acer pseudoplatanus ‘brilliantissimum’ is one of the best, showing pink, green, white and yellow on its leaves. A splendid specimen can be seen near the main entrance at Kew. There is also a wider range of fresh colours to be seen among the many Japanese maples peppered around London’s front gardens and laburnum and lilac time is also now close upon us.
