With the cool smell of autumn on the winds, Kevin Revell shows you how to capture the colours of the season
Autumn flowers are few and far between, but colour is provided in the garden by the changing tapestry of autumn foliage colour which intensifies as the season advances.
This annual show is as eagerly anticipated as the first flower of spring by many keen gardeners and garden visitors. The ‘New England Fall’ colours are typified by larger trees such as Maples, Liquidambar and Rowans. There are nevertheless, a range of smaller shrubs which are easier to accommodate in our modern gardens, where everything has to justify its place and not outgrow its welcome.
The changing foliage colour is caused by pigments in the leaf used for protection from ultra-violet light being revealed by the breakdown of the chloroplasts. These contain the green pigment chlorophyll, a valuable molecule for the plant, the constituent parts of which are reclaimed and stored through winter. This reveals the anthocyanins and carotenoids within the leaf which gives us the familiar autumn colours.
The season can be frustratingly short as the colour exhibited by the fading foliage can be lost to an overnight storm. The autumn display is vital in marking the turn of the seasons; a careful choice of plants can extend the season over several weeks.
Occasionally a long spring followed by a warm summer will lead to a wonderful show where the autumn colour goes on and on. Japanese Maples are the epitome of good autumn colour and to see them at their best, it is worth visiting local parks, stately homes and arboretums to see a display which is impossible to replicate in our own modest circumstances. Plant combinations can be copied and a little bit of Westonbirt brought home can add to the seasonal interest of our own gardens.
Top Five Shrubs for Autumn Colour
Acer palmatum – Japanese Maple
Although perhaps regarded as a small tree, these plants are a varied bunch and many of them are extremely slow growing and multi-stemmed, making them at least nominally a shrub, for a few years at least. Even fully grown they rarely exceed 4m and the weeping types with the dissected foliage are a lot more manageable at less than 2m. Fallen leaves reveal the tortured, twisting tracery of branches which make an attractive sculptural feature through winter. The green form Acer palmatum ‘Dissectum’ exhibits the greater change in colour as the apple green leaves turn orange and red, while the upright form ‘Osakazuki’ turns from green to cerise pink. Best left unpruned to prevent disease getting into the wood, they rarely outgrow their allotted position and are happy in pots and containers which will also restrict their height, rather like a bonsai tree. A sheltered, part-shaded position is ideal both to prolong the autumn display and to protect the emerging foliage in spring which can be scorched by wind and strong sunlight.
Amelanchier lamarckii – Snowy Mesphilus
A useful all-round shrub in the garden, with three seasons of interest between the spring flowers, summer fruit and rich autumn foliage. It is also an attractive plant for wildlife and a good indicator of warmer spring weather approaching when it erupts into a cloud of blossom which fades to reveal the emerging coppery new foliage which itself matures to mid green. Usually grown as a large shrub of 2-3m, it can also be grown as a small, single stemmed tree where it will eventually reach 4-5m. A low maintenance plant, no pruning is necessary and little feeding required, it has a rather untidy habit which is usually disguised by the abundant cloak of summer foliage.
Cotinus coggygria ‘Ruby Glow’ – Smoke Bush
A new compact variety of this superb deciduous shrub which starts the year olive green, the new shoots becoming suffused with ruby red as summer progresses before turning shades of orange and red in autumn. Although compact growing, it is capable of reaching 2m if left alone. With hard pruning in autumn or winter, taking the stems below 50cm, its size can be restricted to less than 1.5m and the foliage colour and leaf size will be enhanced. The smoke-like haze of wispy red inflorescences are produced on mature growth, being absent from hard pruned plants. With a range of attributes from bright foliage colour to good, autumn colour, this is a highly recommended shrub which gives a welcome alternative to the usual green palate of garden colour.
Euonymus alatus ‘Compacta’– Winged Spindle
While Euonymus is best known as an evergreen groundcover plant, there are a number of deciduous forms which display excellent autumn colour. The large growing native spindle Euonymus europaeus has bright red autumn colour but the smaller winged spindle goes a shocking cerise crimson which in a sheltered spot, will persist for a number of weeks. They may be accompanied by shocking coloured pink fruits which split to reveal bright orange seeds. A further benefit is provided by the corky wing-like structures which develop on the bark as the stems mature, giving winter interest to the mature plant. This is another low maintenance shrub which requires no pruning and should not exceed 1.5m. Although attractive to look at, care needs to be taken with placing this shrub as all parts are toxic.
Viburnum plicatum ‘Maresii’ – Viburnum
That few viburnums have acquired a common name perhaps explains their relative unpopularity, but they are surely one of the best groups of plants for the garden. This one is a real winner, having attractive ribbed, oval green leaves on evenly tiered branches which fill out over time to 1.5m-2m. Complex flower heads like mini lacecap hydrangeas add to the interest in early summer which turn to bright red berries by late summer. The highlight is surely the red and purple hues of the winter colour which is extremely persistent and is only lost with the extreme storms of early winter weather. Other varieties such as ‘Pink Beauty’ are equally garden worthy, having a pink blush to the fading flowers and a stronger red tinge to the autumn colour.
Kevin Revell is Plant Area Manager at Caerphilly Garden Centre