Flaming autumn
Maximise the seasonal colour in your garden with these great choices
EVERY autumn it’s good to pause and breathe in the beauty of the seasonal foliage. The picturesque combination of red, purple, orange and yellows is the result of chemical processes that take place in the trees as the seasons change from summer to winter. But what’s the science behind this?
During the spring and summer the leaves have served as factories where most of the foods necessary for a tree’s growth are manufactured. This food-making process takes place in the leaf in numerous cells containing chlorophyll, which gives the leaf its green colour. Along with the green pigment are yellow to orange pigments, which for most of the year are masked by large amounts of green colouring.
But in the autumn, because of changes in the length of daylight and changes in temperature, the leaves stop their food-making process.
The chlorophyll breaks down, the green colour disappears, and the yellow to orange colours become visible. That’s when the great displays happen.
Other chemical changes may occur which form red pigments most vividly seen in maples, while mixtures give rise to the purple hues of dogwoods, liquidambar and parrotias.
For smaller gardens, shrubs are a wonderful way of introducing colour in autumn and all year round. Cotinus coggygria ‘Royal Purple’ has deep maroon leaves on long slim stems that bring form and structure to a planting scheme and which turn scarlet in autumn. If purple is too dark for you, ‘Pink Champagne’ is a smaller smoke bush with bubbly pink flower plumes in summer and pale green leaves which transform to crimson in fall.
Viburnum farreri has beautifully shaped leaves that produce bronze to purple tints in autumn and then clusters of white flowers from November through to the following spring. Its cousin, Viburnum opulus is a real stunner. The leaves flushing red in autumn, along with its clusters of shiny red berries, make it a must have.
Smaller trees such as Japanese maples are renowned for their autumn colour, and as they are typiother cally compact and slow-growing, many are suitable for putting in containers.
Acer griseum is a compact tree with wonderful, peeling bark. Its fresh green leaves turn glorious shades of yellow, orange and red in autumn.
Our native spindle, Euonymus, has glorious autumn colour, with its dark green leaves turning a flaming russet at the same time as its fruit ripens to pink and orange.
It can be grown as a small tree or shrub. ‘Joseph Rock’ is a mediumsized rowan tree with yellow berries, which contrast beautifully with the red and orange of its autumn leaves. Lots of creamy white flowers in spring make for an excellent ornamental garden tree that will enchant for many months of the year. Amelanchier lamarckii is a small, bushy tree or large shrub renowned for its showy April blossom and gorgeous autumn colour, and is perfect for small gardens.
Native to North America, Rhus typhina is a striking tree with branches that resemble stags’ horns. Candle-like green flowers appear in spring, followed by red fruits that resemble velvety pine cones. In autumn the pinnate green leaves fade to red, orange and golden yellow, which complement the dark red fruits beautifully. It can be grown as a shrub or small tree but may produce suckers which can be a nuisance.
All these shrubs and trees are widely available in most local plant nurseries and all are fabulous if you are looking for some autumn impact in your garden.