Clumber Gardener: The fascinating mysteries of autumn colours
Autumn foliage colour can be one of gardening’s great mysteries.
Even if the conditions thought to produce the most spectacular leaf colour combine, there is no guarantee that trees and shrubs will respond and put on a show.
In small gardens, planting shrubs which just produce autumn foliage colour could be considered something of a luxury.
So it makes sense to use varieties which also contribute at other times of the year and earn their keep in the garden across more than one season.
Top of most people’s list would undoubtedly be the deciduous azaleas.
There are hundreds of varieties, mainly producing flowers during May in shades of orange, yellow and pink.
They need an acid soil and will do best in a sheltered spot in light shade.
Hybrids vary in height and will provide rich autumn foliage colour in yellows, oranges and scarlets.
Gibraltar, whose crimson-orange buds open to reveal large, orange flowers and Klondyke with red buds which produce large orange-yellow flowers, are two of the most flamboyant of the group.
They can be combined to good effect with late flowering, brightly coloured tulips such as the multi-headed ‘Red Georgette’ or ’Allegretto’, which has red petals edged yellow.
A close relative to the azalea is the ‘pagoda bush’, Enkianthus campanulatus.
It needs the same conditions and bears many small cream coloured, bell-shaped flowers in May.
The autumn foliage reliably colours bright yellow, orange and red.
Our native ‘guelder rose’ Viburnum opulus, found in hedgerows and the edge of woodlands, is a plant for three seasons .
White flowers in June and July, similar in appearance to a lace cap hydrangea, are followed by fiery autumn foliage and glistening red berries which persist into the winter.
There are also yellow fruited and compact growing forms.
Plant them in full sun in moisture-retentive soil for best results.
Amongst the foliage plants, the Japanese maples are real value for money plants.
Their many leaf forms and colours, be it finely cut, purple or golden, add interest from spring to autumn.
Their two hates are cold winds, which will cause the leaves to brown, and early morning sun, which can scorch young foliage.
One of the best for autumn colour is Osakazuki, whose green summer leaves colour bright scarlet in October.
Where space is limited, they can be grown in containers and will colour equally well.
For the smallest of gardens, the hardy plumbago, Ceratostigma willmotianum, earns its keep.
Bright blue late summer and early autumn flowers are followed by red foliage.
It forms a low growing shrub, so stems should be cut back to ground level each April, just before growth begins.
A sunny spot, sheltered from strong winds and any well drained soil will produce the best display.
The same applies to the aptly named Euphorbia ‘Bonfire’ which is more herbaceous than shrubby.
This plant has typical spurge flowers in May and a Joseph’s coat of foliage, turning from green and purple to burgundy in the summer, then colouring bright red in late summer and autumn.
Autumn foliage is just one of the ingredients which provide interest at this time of year.
Berried shrubs such as cotoneasters, pyracanthas and roses can be relied on.
There are even hardy flowers to be had, from bulbous nerines and schizostylis to autumn gentians.
These are a real pick-me-up as daylight hours shorten, the evenings draw in and the clocks are put back at the end of the month.
We are now into October so it’s time to plant spring flowering bulbs such as tulips, daffodils and hyacinths.
Prune blackberries and hybrid berries such as Loganberries and Tayberries by cutting back the old fruited canes to ground level and tying canes produced this year to supports.
Keep an eye on the weather forecasts for the first sharp autumn frosts.
Lift tender perennials such as dahlias, cannas and gladioli before the cold weather damages them.
October can be a good time to plant container grown hardy perennials and shrubs.
In warm, moist soil plants can establish and make good root growth before the onset of cold winter weather.
If you heat your greenhouse over the winter, put up insulation such as bubble pack to reduce heating bills.
Check that your heater is working properly