The environment is in crisis. New studies confirm that invertebrate populations, including insects, are in alarming decline and could be extinct within a century. With invertebrates comprising half of the world’s species, this would be the world’s 6th major extinction. The world will continue, but without us.

Even in my rural smallholding, surrounded by pesticide-free fields, I’m acutely aware of this collapse. Fewer bumblebees and hardly any aphid-devouring wasps this year.

As individuals, we can’t stop this, but we can help mitigate the problem in our area. This week, I’ll consider how we can make our gardens and surrounding areas a haven for remaining invertebrates. And next week, I’ll look at lawns, grassed verges and parks.

Researchers identify pesticides as a major cause of the problem. Although commercial operators can still use these potions, fewer are thankfully available to gardeners. We should follow France where private individuals are no longer allowed to buy or use pesticides. Although this only affects 10% of pesticides sold, it’s an important step in the right direction.

Pesticides kill everything, including creatures we consider ‘beneficial.’ So between 2000 and 2009, there was a 58% decline in butterflies in England, and since 1945 half the bumblebee and honeybee populations in the U.S. have been eliminated.

Enlightened gardeners do our best for a garden’s invertebrates by protecting our crops rather than killing ‘pests’. Fleece and cabbage collars force rootfly to feed on wild plant species, and nets keep cabbage white butterflies away from brassicas or sweet-toothed birds from our strawberries.

But, when buying plants, we mustn’t drop our guard. Dave Goulson’s research in 2017 looked at neonicotinoids, pesticides lethal to pollinators. He showed that plants using the RHS ‘Perfect for Pollinators’ label had sometimes been doused in neonics. And even though the label now reads ‘Plants for Pollinators’, the poison is still used by some growers.

So, let your nectar-lovers feed safely by getting new plants from organic or pesticide-free nurseries. Use B&Q or Aldi or ask your garden centre to confirm that they only purchase neonicotinoid-free plants.

But pollinators are only one group of invertebrates and a thriving ecosystem also needs the other, possibly less ‘glamorous’ ones, including beetles and leafhoppers. Although bees happily suck nectar from non-native plants, other invertebrates may be host-specific. They may rely on native or ‘near-native’ plants from northern temperate regions and be unable to switch to more exotic species.

And leafhoppers aren’t our only unsung heroes. As I never tire of saying, the soil with its many billions of inhabitants is the most important part of any garden. Many of our insects start life in the soil and other invertebrates, such as worms, play a critical role in creating a soil where plants and all their dependants can thrive. Soil is an asset we squander at our peril.

When digging a carrot or a leek, I knock the soil back into the ground, or scrape it into the compost bay when tidying for the kitchen, rather than washing it down the sink.

And there are so many ways of damaging our precious soil. Herbicides applied to weeds on paths or lawns are often washed into beds, along with rainwater. Without a protective mulch, soil is leached away during winter downpours. Only when the level of a bed sinks, do you realise the scale of this erosion.

And after every storm, my angry brown burn sweeps an untold mass of soil off to the North Sea. I’m not surprised that a recently-published study shows that 2.2 million tonnes of U.K. topsoil is eroded annually.

Plant of the week

Grey willow. The fluffy catkins are a welcome indicator of spring, providing an early nectar and pollen source for bees and other insects. The leaves are the food for a number of moth species that, in turn, feed birds.