For me, November is a month of mixed emotions. I struggle with the shorter hours of daylight, and the prospect of those seemingly interminable months of bleakness to come. Don’t talk to me of hygge or cosying up by the fire. I want to be out there, inspired by the colours and new life of the garden. I start my countdown to spring in January, but for now there’s a poignant joy to be had in the colour of autumn leaves, which seem particularly vivid this year.
Small is beautiful
I have two acers in the back garden. We live in a south London Victorian terrace, so trees must earn their keep. One is in a huge pot by the French windows that leads out to the garden. The other is about 6 metres down the garden in an east-facing border. Right now it’s dazzling in the morning sun, resplendent against the backdrop of a clear, bright blue November sky. The leaves are copper and gold, and falling fast to reveal the acer’s stately, shapely skeleton.
The ground below is carpeted with buttery yellow and bronze leaves. They mingle splendidly with an evergreen euonymus growing under the acer, its variegated green and white peeping up freshly through the tangle of autumn richness. I love a happy accident like this.
The lawn, too, is a tapestry of gold and red from the acer, and yellow from my struggling Robinia pseudoacacia ‘Frisia’ in the opposite border. The stepping stones through the grass are barely visible now. There’s no way I’m going to worry about raking up those leaves when they’re so pretty, though. I’ll leave it until they’re soggy and brown. Lawns are tough; it will bounce back in spring.
The science of nature
All this autumn loveliness started me thinking about the science behind leaf fall. Why are some trees evergreen and others deciduous? And why and how do the leaves change colour and drop? It’s all to do with the chlorophyll and sugars in leaves. Without getting too technical, leaves drop to save the tree energy needed for photosynthesis over winter as it goes into a kind of plant hibernation (there’s not enough sunlight to grow well, so why bother?) The shortening of the days in autumn triggers a drop in a hormone called auxin. This causes the leaves to shed.
The foliage of evergreens, on the other hand, is covered in a waxy coating - think pines, fatsias, choisyas and so on. This conserves moisture, which is needed for photosynthesis, so these trees don’t need to shed their leaves in winter.
Acers are probably the stars of this seasonal show. They’re one of the easiest trees to grow for autumn colour. They’re useful, too, as there are more than 700 different cultivars, many small enough for eventhe tiniest city garden. Browse the selection at Ashridge and you’re bound to find one to suit you and your garden.
Sorbus, or mountain ash, is another tree that comes out on top for autumn colour, not just for its rich yellow leaves, but for the generous dangling clusters of berries, in a remarkable range of shades, from pillar-box red to gold, pale yellow and ghostly white. Check out your options here.
Then there’s Cercis canadensis ‘Forest Pansy’, with its divine heart-shaped leaves that turn the colour of mulled wine in autumn. It’s bushy and spreading, with pea-like candy floss pink flowers in spring, so that’s two seasons of gorgeousness in one tree.
Let it snow
I’d love to plant an amelanchier, or snowy mespilus in my garden at some point, maybe to replace the ailing robinia. Its autumn foliage is a warm, deep pink, and the early-spring flowers are delicate white stars opening on bare stems gradually revealing new leaflets of the most intense copper colour.
But for now I’ll carry on enjoying the leaves of my acers, until there’s nothing left but the graceful spreading branches, the tree conserving its energy for that lovely vibrant green spring growth.
Francesca Clarke, Journalist and Garden Designer