As the days shorten and the temperature drops in the autumn months, spectacular leaf colour ignites the Botanic Garden. But in the Autumn Garden in particular, foliage colours, from vivid coral to deep purple, are revealed as the dominating green chlorophyll breaks down and combine with late flowers, seedheads, fruits and feathery grasses to become a beautiful, richly textured tapestry.
Some of the best displays of fiery autumn foliage are provided by the Sweetgums, Liquidambar styraciflua ‘Worplesdon’ from America and the related L. orientalis from Turkey. The latter species, although rarely grown, is a valuable late colourer and the decaying, star-shaped leaves take on glowing deep-orange tones in late autumn. This very effective Sweetgum duo is repeated on the Lake’s northern shore.
Many different species of Smokebush (Cotinus) provide a foliage tapestry of flaming reds, pink, clarets and oranges against which the pale grey or coral smudges of the spent inflorescences are pinned. Other autumn leaf colour comes from many Acer species, including a trio of Acer palmatum ‘Osakazuki’. The palmate, seven-lobed leaves are wine-red, purple, pale coral and orange to begin with, each leaf held on a slender, cerise-pink stalk as are the samara fruits – a pair of seeds held in papery burgundy wings. Weeks later, the foliage has reduced to a deep wine colour, making a vibrant contrast to the butter-yellow, fan-shaped foliage of a neighbouring Maidenhair (Ginkgo biloba). The soft, feathery foliage of a Dawn Redwood (Metasequoia glyptostroboides) contributes a coppery russet, a lovely upward sweep of fox-fur colour against a cushion of glaucous evergreens.
The low and mid-level plantings are enlivened with late flowers such as the lilac-coloured goblets of Autumn Crocus (Colchicum autumnale), the dense platform flowers of Sedum, beloved by bees and butterflies, and clouds of sky-blue Aster x frikartii. The stately plumes of Pampas Grass (Cortaderia selloana) provide the backdrop.