Planting for pollinators: The insect-friendly garden

It’s estimated that one in three mouthfuls of our food depends on pollinators, as do about 80 percent of flowering plants grown in the UK. This includes many of our perennial and annual garden flowers as well as wildflowers. Strawberries, cherries, apples, peas, runner beans, courgettes…  Many of our favourite fruit and veg need insects to transfer pollen from flower to flower, produce what we eat and complete their reproductive cycle to ensure that they do it again the following year.

Insects are also part of the essential food chain that keeps our planet buzzing, tweeting, howling and roaring (and that’s just the humans). Insects are eaten by birds and the pollination they carry out helps produce the seed and fruit that wildlife eats. Moths are eaten by bats and it’s estimated that bluetits eat a whopping 50 billion caterpillars in the UK and Ireland each year. And long-tailed tits really  love a quick moth egg snack.

We all know that bees and butterflies are essential pollinators. But did you know that others have a crucial role too?

Moths: we tend to notice moths less than butterflies because most fly at night. But, a recent study shows, the 2,500 species of moth in the UK are responsible for about a third of pollinator visits to flowers, fruit and trees. And not all moths are nocturnal. You can see both the hummingbird hawk-moth and the red and black six-spot burnet moth during the day.

Beetles: including ladybirds and the extraordinary, iridescent, thick-legged flower beetle. Look out for it on cow parsley or blackberry flowers on sunny days – its shimmering green shell and comically plump legs make it easy to spot.

Hoverflies: friendly, curious or just plain nosy depending on your point of view – there over 280 species of these non-stinging, non-biting flies in the UK. Others like the rather endearing and very small drone fly are important too.

Population decline

Moths have declined by a third and butterflies by 80 percent in the last 50 years. Across Europe, 38 percent of hoverfly species are in decline. As for wild solitary and bumblebees – we’ve already lost 13 species and another 35 are currently at risk. We know the causes. Habitat loss, climate change and the use of pesticides have all played their part.

But there is some good news. A few bee and hoverfly species in Europe are on the up. And last year’s UK Big Butterfly Count showed that some species had increased from the previous year, including the holly blue (up by 120 percent) and the brimstone (up by 37 percent). Some of this is thanks to habitat management by conservationists and by ordinary people creating wildlife-friendly gardens and balconies, choosing and encouraging the plants that insects need for fodder.

Food for thought

We’re fortunate to live on a planet with a beautifully intricate and complex web of relationships between all living things. Different species of insect need different habitats to survive and thrive. Thus the silver-washed fritillary butterfly lives in woodland areas with open, sunny glades, whereas the meadow brown’s home is on grasslands.

Various insects have evolved special relationships with a range of plants. And moths and butterflies, of course, begin life as eggs which then become caterpillars. So it’s not just the adults we need to consider. Caterpillars are fussy about their food and most butterflies and moths will only lay their eggs on a few, well-chosen plants. Trees, shrubs and grasses, as well as flowering herbaceous plants, all play their part.

These are a few examples of the menu options we can offer in our gardens.

Plants for moth caterpillars

Dull old privet is essential for the privet hawk-moth and the willow beauty, yarrow (Achillea millefolium) for the tawny speckled pug, and our native honeysuckle, Lonicera periclymenum, for the astonishingly well-camouflaged early grey and twenty plume moths.

Plants for butterfly caterpillars

Honesty (Lunaria annua) for the stunning orange tip, nasturtiums for the large white, small white and green-veined white, and common or garden dock or sorrel for the small copper. And don’t forget the grasses – six types of butterfly caterpillar, including the gatekeeper and speckled wood, feed on them, so try leaving an area of your lawn long and see who turns up.

For adult pollinators

Bowl-shaped flowers with open centres such as crocus and some roses are easy for most insects to get to.

Lipped flowers, like sages and laburnum, provide a landing area for bees to sit on comfortably while they nose their way in and are often sought out by bumblebees and solitary bees.

Flowerheads composed of many small florets with deep wells, such as Verbena bonariensis and scabious, are just the right shape for the long tongues (proboscis) of moths and butterflies.

In short, a having a range of flower shapes will attract a greater variety of pollinators. And if your garden is big enough, planting in blocks does them an additional favour as they’ll expend less energy flying from flower to flower.

Three insect-friendly essentials:

• Highly-bred double flowers with many overlapping petals and closed centres are hard for pollinators to access. Many also produce little pollen or nectar.
• If you can, choose a diversity of plants that will provide flowers for as much of the year as possible.
• Avoid using pesticides.

There’s a comprehensive month-by-month list here to help you decide what you could plant and plan your shopping.

https://www.rhs.org.uk/science/pdf/conservation-and-biodiversity/wildlife/plants-for-pollinators-garden-plants.pdf

Go the extra mile

Any other support you can offer will be gratefully received.

Insect hotels and log and leaf piles as well as undisturbed areas of the garden provide shelter for overwintering moths, butterflies, beetles and bees, most of which will be dormant either in their adult form or as eggs, larvae, caterpillars and pupae.

Go out with your kids and see what you can find. Getting them interested and involved is a great way to ensure we continue to build a healthy environment for pollinators.

https://schoolgardening.rhs.org.uk/Resources/Spotter-Guide/Pollinating-Insects-Spotter-Guide

Citizen science provides valuable information for researchers, helping them to pinpoint species on which to focus conservation efforts. This year’s Big Butterfly Count has just finished but there’s always next year, so keep a look out in early summer!

Pollinator power

Without pollinators we would have no chocolate, no avocados and no melons. And even plants that are essentially self-fertile, such as tomatoes and aubergines, will produce more fruit with assistance from flying invertebrates.

Some butterfly species like the red admiral and painted lady are migratory. A number of moths, for instance the hummingbird hawk-moth, and hoverflies also migrate.  Some are simply spreading their wings in search of new territory after a successful breeding season, others are flying south for the winter to warmer climes in Europe and North Africa, sometimes in vast numbers. In spring 2009, around 11 million painted ladies arrived, with an estimated 26 million then leaving in autumn. It’s not unknown for extraordinary distances to be covered too. The painted lady may navigate a jaw-dropping 7,500 miles during migration over three quickly-reproducing generations. So by creating a welcoming habitat on your own turf you’re helping pollinating insects – and crops – elsewhere too.

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