In nature, nothing is wasted – fallen tree leaves and twigs serve as food and shelter for fungi, mammals, insects and invertebrates, and countless microorganisms, which in their turn feed the trees by returning the nutrients to the soil in the form the tree roots can absorb. Other plants and animals take part in the cycling of nutrients, their waste products serving as food or resources for others. None of them goes around the woods specially dispensing fertilisers, watering, or tidying, yet the plants and animals are fed and watered, and dead leaves and branches are gradually reabsorbed into the woodland floor to create rich soils that are high in organic matter and have great moisture-holding capacity. In woods, there are no gardeners, yet ‘everything gardens’ to contribute to the overall abundance.
Many gardens are the opposite of this, because bare soil, manicured flowerbeds, and straight lines, while aesthetically pleasing to some, are at odds with nature’s potential to renew and regenerate itself. With no habitat or food for friendly insects and microorganisms, we have to step in to perform their tasks, endlessly weeding and watering, trimming, sweeping, feeding plants and combating their pests and diseases which spread in the absence of competition from the ‘good guys’. Granted, some of these tasks may be unavoidable if we want to stop paths, roads and lawns reverting to woodland floor, but others are not only unnecessary but harmful to the health of soil and plants.
Bare soil is hammered hard with rain and then dried by the wind and sun to form a surface crust which repels rain water, causing its run-off into the roads around, while the plants are stressed from the lack of soil moisture. Blocked soil pores stop effective air movement within the soil, so when the soil does get wet, it does not admit enough air to dry out, creating an anaerobic environment which is damaging to plant roots. Poor habitat for soil life means that plants struggle to get adequate nutrition as well, which no amount of artificial fertilisers is going to compensate for – so fine-tuned is the interdependence of plants and the soil microbiology. Far from being a hallmark of ‘tidy’ gardening, bare soil is a zone of ecological disaster.
How can we bridge this apparent impasse between ‘good gardening’ as nature sees it, and aesthetic expectations of the majority of the population? Enter mulching. A novelty concept still in the 1960s (despite having been in use since before written records of gardening practices appeared in the 17th century), it has finally caught on and entered the mainstream. Composted bark and woodchip are marketed as a means to prevent weed growth, conserve moisture and slowly release nutrients to the soil. Other functions of organic mulches include protecting the soil surface from being baked by the sun and eroded by rain and wind, and slowing run-off by intercepting more rainwater and allowing it to penetrate into the ground over a longer period of time.
Bought mulches are expensive, but not many people realise that almost anything organic can serve as a mulch – from shredded paper statements to vegetable peelings – as long as it feeds the helpful insects, invertebrates and microorgansisms! (But don’t go pouring out spoilt milk onto your prised rose patch...) Tree leaves and clippings, dead branches, mown grass, and even weeds make a brilliantly diverse source of food and a great habitat for these creatures, as well as some very desirable mammals like hedgehogs, which would find no shelter on bare beds and borders. Gradually, as these materials are shredded, digested, excreted, and taken up as food by plants, what was a thick layer of mulch in autumn is all but gone by late spring.
Woody mulches and leaves, being rich in lignin, are particularly palatable for beneficial soil fungi that form huge underground bodies consisting of microscopic long threads called hyphae, which serve to channel water and nutrients over vast areas of land from tree to tree. Some fungi form associations with plants to expand the reach of their roots both outwards and inwards: being thinner than plant roots, hyphae are better at penetrating into the tiniest gaps between soil particles to extract water even in seemingly bone-dry soil. The prevalence of soil fungi serves to discourage the germination of annual weeds, and coupled with mulches serving as a physical barrier to weed growth, effectively reducing the need to weed.
Mulching with a good layer of diverse materials (leaving leaves, hedge clippings, weeds, small branches, home-made compost, woodchip etc.) turns dry, unworkable soils around in a few months: if you pull back the layer of mulch, you’ll often the white strands of fungal mycelium growing though it and into the soil. Greater diversity of materials supports a wider range of organisms and may yield a number of edible species of fungi for human food too: blewits, suede boletes, spring fieldcaps, amethyst deceivers, and (occasionally!) morels have all been spotted growing in mulched beds and borders!
Many gardens are the opposite of this, because bare soil, manicured flowerbeds, and straight lines, while aesthetically pleasing to some, are at odds with nature’s potential to renew and regenerate itself. With no habitat or food for friendly insects and microorganisms, we have to step in to perform their tasks, endlessly weeding and watering, trimming, sweeping, feeding plants and combating their pests and diseases which spread in the absence of competition from the ‘good guys’. Granted, some of these tasks may be unavoidable if we want to stop paths, roads and lawns reverting to woodland floor, but others are not only unnecessary but harmful to the health of soil and plants.
Bare soil is hammered hard with rain and then dried by the wind and sun to form a surface crust which repels rain water, causing its run-off into the roads around, while the plants are stressed from the lack of soil moisture. Blocked soil pores stop effective air movement within the soil, so when the soil does get wet, it does not admit enough air to dry out, creating an anaerobic environment which is damaging to plant roots. Poor habitat for soil life means that plants struggle to get adequate nutrition as well, which no amount of artificial fertilisers is going to compensate for – so fine-tuned is the interdependence of plants and the soil microbiology. Far from being a hallmark of ‘tidy’ gardening, bare soil is a zone of ecological disaster.
How can we bridge this apparent impasse between ‘good gardening’ as nature sees it, and aesthetic expectations of the majority of the population? Enter mulching. A novelty concept still in the 1960s (despite having been in use since before written records of gardening practices appeared in the 17th century), it has finally caught on and entered the mainstream. Composted bark and woodchip are marketed as a means to prevent weed growth, conserve moisture and slowly release nutrients to the soil. Other functions of organic mulches include protecting the soil surface from being baked by the sun and eroded by rain and wind, and slowing run-off by intercepting more rainwater and allowing it to penetrate into the ground over a longer period of time.
Bought mulches are expensive, but not many people realise that almost anything organic can serve as a mulch – from shredded paper statements to vegetable peelings – as long as it feeds the helpful insects, invertebrates and microorgansisms! (But don’t go pouring out spoilt milk onto your prised rose patch...) Tree leaves and clippings, dead branches, mown grass, and even weeds make a brilliantly diverse source of food and a great habitat for these creatures, as well as some very desirable mammals like hedgehogs, which would find no shelter on bare beds and borders. Gradually, as these materials are shredded, digested, excreted, and taken up as food by plants, what was a thick layer of mulch in autumn is all but gone by late spring.
Woody mulches and leaves, being rich in lignin, are particularly palatable for beneficial soil fungi that form huge underground bodies consisting of microscopic long threads called hyphae, which serve to channel water and nutrients over vast areas of land from tree to tree. Some fungi form associations with plants to expand the reach of their roots both outwards and inwards: being thinner than plant roots, hyphae are better at penetrating into the tiniest gaps between soil particles to extract water even in seemingly bone-dry soil. The prevalence of soil fungi serves to discourage the germination of annual weeds, and coupled with mulches serving as a physical barrier to weed growth, effectively reducing the need to weed.
Mulching with a good layer of diverse materials (leaving leaves, hedge clippings, weeds, small branches, home-made compost, woodchip etc.) turns dry, unworkable soils around in a few months: if you pull back the layer of mulch, you’ll often the white strands of fungal mycelium growing though it and into the soil. Greater diversity of materials supports a wider range of organisms and may yield a number of edible species of fungi for human food too: blewits, suede boletes, spring fieldcaps, amethyst deceivers, and (occasionally!) morels have all been spotted growing in mulched beds and borders!