In some areas quite severe frosts are common in early autumn, and in others light frosts may not occur until mid or late autumn, if at all. Think seriously about winter protection for plants on the borderline of hardiness, and be prepared to give early winter shelter, perhaps in the form of a windbreak, for newly planted evergreens. A little protection can ensure that many plants survive instead of succumbing to winter winds and cold.
The weather in early autumn is still warm enough to make outdoor gardening a comfortable experience, and although the vibrant flowers of summer might be gone, there are plenty of delights to be enjoyed in the form of bright berries and flaming foliage, not to mention late-flowering gems such as chrysanthemums and nerines. Apart from the bulb planting, and protecting frost-tender plants, there are few really pressing jobs at this time of the year.
Make the most of plants with colourful autumn foliage by planting them on both sides of travelled path or areas that can be seen from the windows of your house. Autumn colours will be especially brilliant after a hot summer, but they miay not last as long as in a less extreme year. You can make that the colours are prolonged by severely restricting the water supply to any plants that start to develop colour after the end of the summer . Plants that colour well in October-March, need moisture in early March – September. For instant colourful effect, autumn flowering bulbs, corms and tubers are unsuppressed. If planted in late summer, many of them will flower within a month, bringing bright colours to your garden (Clumps – Crocus speciosus, Stembergia lutea, Cyclamen hederifolium, Colchicum bivonae).
Most bulb displays are less predictable than summer flowers and it can be especially disappointing when different bulbs planted in a same window box at different times. The consolation is that this does at least extend the interest. A good alternative is to plant single subject displays which, are frequently bolder. Tubs, large pots, and urns can be planted in the same way as window boxes – with bulbs in multiple layers or combined with spring-flowering plants, but bulbs also make good companions with shrubs and small trees in tubs. They make the most space around the edge of the container that is usually wasted, and if the shrubby plant sheds its leaves in winter, the bulbs will complete the important parts of their annual cycle before there is competition for light.
Few perennials can also offer the variaty of colours and shapes. For a fairy touch you can Kriphofia hybrids (red hot pokers) or Aster ericoides , the “Pink Cloud, with small pink, daisy -like flowers.
An evergreen planted in late summer or the autumn may not have grown new roots out into the soil, and if not watered regularly, it will not be able to absorb water as rapidly as it is lost. A wind break for the first winter will reduce moisture loss and help a vulnerable plant to survive. Insert three stout canes or stakes around the plant, then wrap a plastic sheet or several layers of horticultural fleece around the edge. Peg down the bottom. If you don’t want to erect a shield, perhaps on aesthetic grounds, water in very dry spells to keep the roots moist , and cover with a large plastic bag, pegged to the ground. It can be removed after a severe weather.