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Insects are vanishing - what can gardeners do to help reverse this worrying trend?

oxeye daisies
Bee foraging on astrantia, a type of umbellifer

Some gardeners labour under the misapprehension that flowers were invented purely for our use. In fact, we don't figure in the equation at all: flowers exist for the procreation of the plant, and the most important creatures in this process are insects.

Unfortunately insect numbers have been declining for decades, and many gardeners are well aware of the lack of butterflies, bugs and bees in our gardens compared to just a few years ago. Now a recent global review has confirmed that insects are becoming extinct eight times faster than mammals, birds and reptiles.

Without insects, scientists are predicting a “catastrophic collapse of nature’s ecosystems”.

As gardeners, we have a vested interest in plants flowering and setting seed. Little of this would happen without insects. In the past, much emphasis was put on destroying the insects that eat our plants or harm them.

Now enlightenment is slowly spreading and we realise that in an harmoniously balanced garden there is no need for pesticides, and that encouraging insects will give us healthier plants.

Oxeye daisies at Flower Farms at Shalbourne, near Hungerford, owned by Charles Flower Credit: Christopher Jones for the Telegraph

Important garden insects

  • Wasps are much maligned, yet they prey on caterpillars, storing them in their papery nests for their larvae to feed on when they have hatched. Rather than kill wasps, aim to lure them away from outdoor seating areas by hanging up a fake nest (it deters the competition).
  • The larvae of hoverflies and ladybirds prey on aphids and clean up  our plants. Get to know the larval stages of beneficial insects so that you don't mistake them for baddies - and leave any infestations to the birds to sort out, they need to eat too.
  • Bees and hoverflies, moths and butterflies are on the wing around the clock, extracting nectar and spreading pollen from stamen to stigma. Both partners derive benefits from their relationship, and they have evolved to serve each other. We gardeners can enjoy them all.

Best plants to grow

Umbels (cow parsley is the best known example) are good news for flying insects of all sorts. Tall, showy Angelica gigas is especially attractive to hoverflies, flies and wasps. All members of the umbel family (Apiaceae) have flowerheads made of scores of tiny flowers. Read about the top umbellifers to grow here.

Pulmonaria 'Lime Close' Credit: Paul Beard Photo Agency / Alamy

Bees need food from the moment they emerge and we are all in a position to help them by including plenty of early flowers in our gardens. In spring, pulmonarias, such as ‘Mawson’s Blue’ are nectar-rich and provide life-giving ambrosia. Pulmonarias belong to the borage family, along with comfrey, borage and forget-me-nots, all of which are important sources of nectar.

In early summer, motorway embankments and verges are often full of ox-eye daisies (Leucanthemum vulgare). All daisies have composite flowers, their centres comprising a multitude of tiny flowers, disc florets - which contain nectar - and ray florets, or petals which tell insects where they can get their next meal. Read more about other daisies to grow here.

Butterfly on oxeye daisy Credit: Alamy

Flowering shrubs must pull in their pollinators, too. The beauty bush (Kolkwitzia amabilis), is smothered in pale pink bells throughout June and into July. These bells buzz with every size and shape of bee. A large specimen provides sustenance for thousands of insects over a long period, as well as being one of the most attractive shrubs around. Read more about spring-flowering shrubs here.

Although nectar is collected from any flower, native plants are bound to support native insects, so gardens rich in indigenous plants will be very useful to insects. The nettle-leaved bellflower (Campanula latifolia), is one of our most alluring wildflowers. There are named selections, such as ‘Gloaming’, in soft grey-lilac, and ‘Brantwood’ in deep blue. Easy to grow in sun or dappled shade, they are loved by bees.

Pink drifts of Monarda didyma 'Pawnee' at Scampston Hall, Yorks. Credit: John Glover / Alamy

Monardas, such as ‘Prärienacht’ are commonly known as bee balm, and are one of the first ports of call for many insects on a sunny day. A member of the Labiate family, it has typical square stems and a collection of lipped flowers arranged in whorls around them.

Other much-visited labiates include aromatic oregano, salvias and the striking Lamium orvala, a dramatic deadnettle with old-rose flowers. Bees love this, balancing on the lower petal, which forms a landing stage, before disappearing deep into the flower.