The Garden Jungle (or Gardening to Save the Planet)

With so much to be depressed about in the news, both about Brexit and the global climate emergency, it has been a real pleasure reading Dave Goulson’s uplifting book this last week. The book is a fascinating insight into, and celebration of, the surprising (to most of us) diversity of garden wildlife.  It is both a clarion call to change the way we think about our gardens and how they can be better refuges for that wildlife and a timely reminder of the increasingly-accepted benefits for physical and mental health of spending time in a natural environment and tackling small, manageable tasks over which we have at least a measure of control.

For anyone with an interest in natural history, the book has enough ‘fun facts’ to keep you hooked.  Who knew, for example, that the nectar of many citrus species contains caffeine, which has much the same effect on pollinating bees as a morning espresso on many of us? Or that ants make up around a quarter of the total biomass of land-based animals, just like humans. The chapters on bees and ants are fascinating. I had no idea there are so many types of bee involved in pollination, nor did I know much about the life cycles of the many solitary bees; honeybees and bumblebees seem to command most of our attention. According to Goulson, beehives in London are much less productive than the national average as a result of the fashion for urban beekeeping – there is no longer enough nectar and pollen to go around.  He argues that growing a range of plants suitable for different pollinators and providing nest sites and materials for solitary bees in gardens is a much more practical way of supporting bees for most of us.  I, for one, am not sorry to hear this!

The Garden Jungle doesn’t shy away from issues such as the effects of pesticides on the food chain and ultimately on humans. I was shocked to discover that in some US states there is mandatory spraying of urban and suburban gardens with insecticides in an attempt to control invasive Japanese beetles thought to provide a risk to the Californian wine industry and the mosquitos which spread Zika virus.  In the latter case, an organophosphate called Nadel, with a long list of toxic side effects for humans (and banned by EU regulators), is sprayed from planes over large areas of Florida, Louisiana and South Carolina. Arguably, it kills useful insects in much larger numbers than the Aedes aegypti mosquitos supposedly targeted – there is plenty of evidence from around the world that A. aegypti is much better tackled by depriving the insects of standing water for breeding.  This gung-ho attitude to pesticide use alone would be enough to make me very wary of any post-Brexit food deals with the USA.  However equally shocking to me was the fact that plants in UK garden centres labelled as ‘Plants for Pollinators’ were grown using neonicotinoid and other pesticides, often present in quantities toxic to those same pollinators.  A campaign by Friends of the Earth and others led to many companies promising to stop using neonicotinoids but that doesn’t mean they won’t be using alternative, if less well known, insecticides.

To an extent, the jury is still out on the native versus non-native plant debate in terms of maintaining biodiversity. Pollinators are not generally very fussy about what they pollinate but exotic plants tend to have fewer herbivores able to overcome their chemical defences, meaning there are fewer well-fed insects to support birds and other larger garden wildlife. Goulson argues that the variety of a particular species which is chosen may be more important – many garden varieties are bred for ‘showiness’ and may be sterile hybrids lacking pollen, nectar or both.  Double flowers are particularly likely to be of limited use to insects, because of this.  

‘The lawn’ is another area of contention for many UK gardeners, a closely-mown, bright green monoculture often being seen as evidence that a garden is well cared for.  Such a lawn is obviously not going to be a biodiversity hotspot and I’ve long been allowing my own grass to grow longer and adopted a laissez faire approach to the presence of weeds, a.k.a. wildflowers.  The ‘lawn’ now sports dandelions, hawkbits, daisies, white clover, self-heal, speedwells, vetches and a large patch of wild garlic, as well as plantains and dock. None have been planted – all have just ‘arrived’.

Germander (left) and Thyme-leaved (right) speedwells in the ‘lawn’

I like Goulson’s suggestion of mowing a couple of paths through the grass to show it is being allowed to grow intentionally and otherwise largely leaving it be, though I must admit to controlling the number of dock and plantains. I’ve also scattered a lot of yellow rattle seed from a friend’s meadow this year in an attempt to keep some of the more vigorous grasses in check.

The book’s chapter on moths is enough to persuade me to try setting up a moth trap in our garden – who knows what we’ll find.  There are plenty of their blowsy butterfly cousins on our buddleia at this time of year and the ragworts I’m now allowing to flower should attract Burnet and Cinnabar moths as well as the Tortoiseshell butterflies I saw on them earlier in the summer.

Six-spot Burnet moth on Ragwort

A pond has been on my wish list for some time too, though the effort involved means it hasn’t yet materialised.  With this in mind, I love the idea of making ‘hoverfly lagoons’ to encourage these insects, at least, to breed in the garden.  Many hoverflies lay their eggs where water puddles in the forks of old trees, causing the bark to rot and allowing leaves and other organic matter to collect.  You can mimic the ecosystem which develops by simply adding some lawn clippings (if you still have a lawn after reading this far!), leaves and protruding sticks to the bottom half of a plastic milk container filled with rainwater and leaving it somewhere quiet.  Hoverfly larvae (better known as rat-tailed maggots) feed on the decomposing bacteria which thrive in such environments and will eventually climb out of the water into surrounding vegetation to pupate. 

I think the thing I enjoyed most about The Garden Jungle is its pragmatic, can-do approach to encouraging biodiversity.  Most of the actions suggested are adaptable for use on any small piece of land, whether individually or communally owned.  Growing your own plants, whether for food or for wildlife has demonstrable benefits for health and needn’t cost the Earth, in any sense – it can do quite the opposite.  I wonder whether an organisation such as ‘Good Gym’ couldn’t be involved in using community land for this kind of wildlife friendly gardening where people don’t have access to private gardens?  Incidentally, for anyone looking for positive news about such projects I’d highly recommend Ed Miliband and Geoff Lloyd’s Reasons to be Cheerful podcast – recent episodes on tree planting and the climate emergency more generally make encouraging listening. There are things we can do!

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