It is not often that I take horticultural guidance from Network Rail but I have been obliged over the past few weeks to follow their example and introduce a leaf-fall timetable. Day after day, every attempt to embark on my list of gardening tasks has been thwarted by the need to clear paths and lawns of leaves before we could even start.
I do not have anything against leaves, you understand. In truth I consider them among nature’s most remarkable organ creations: the structures that enable plants to manufacture nutrients – more or less from thin air – by trapping the sun’s energy. The process itself – photosynthesis – is by almost any definition a miracle.
And we should never overlook that leaves in their varied shapes, sizes and colours can contribute enormously to the appearance of our gardens. My own has long been more about leaves than flowers – albeit recognising that flowers themselves are just leaves modified over evolutionary time. That said, I have something of an antipathy to variegated foliage. Perhaps it is the Darwin in me that recognises any plant with other than all-green leaves is almost certainly less vigorous and less fit to survive. Nonetheless, at this time of year, shed foliage must be disposed of and it saddens me to see car boot load after car boot load of black bags full of foliage being delivered to the local recycling centre.
Within the constraints of space and time, they are much better recycled in your own garden. But not, please not, in your compost bins. Leaves should go in a leaf mould cage. Compared with lawn mowings and soft vegetable matter, leaves contain a high proportion of resistant chemicals such as lignin and break down and decompose much more slowly, so hindering the composting process. Ideally, all leaves – and certainly those of robust evergreens and big brutish deciduous things like horse-chestnut and sycamore (which have no place in a garden in any event) – really should be passed through a shredder before being stacked. The one serious exception to garden leaf recycling is the foliage of conifers – generally called needles. They are so heavily impregnated with waxes that you will wait forever for them to break down, so they can and should be taken to the tip.
A leaf mould cage can be the simplest of structures: four stout posts placed around a metre square and with fine mesh chicken wire attached. Within a year or so, you will have an invaluable supply of leaf mould, perfect for mulching and in my experience almost essential if you are to grow lilies successfully.
But before anyone asks – no, I add neither water nor fertiliser to my leaf mould or compost. The cages and bins are sited under a large purple-leaved Norway maple – itself a prodigious source of foliage – which seems to prevent them from drying out in summer while allowing plenty of rain to penetrate in winter. And unless it is layered knee-deep – which did happen a few years ago when every leaf in the garden seemed to fall in the same week – I do not clear foliage from beds and borders. With winter rains and our significant local population of earthworms they will have all but disappeared by the spring, and in the process added some nutrient and plenty of structure-aiding matter to the soil.
We have about 25 trees in the garden; Network Rail claims ten million within a few metres of its tracks. Fair justification, then, for a timetable adjustment in both cases.
This article appears in the 31 Oct 2018 issue of the New Statesman, The Great War’s long shadow