The aim of this study was to provide seasonal recommendations to gardeners to ensure pollinators are appropriately supported throughout the year. We identified the plants visited by pollinators by characterising the DNA within pollen found on their bodies, using a process known as DNA metabarcoding. Here, we outline some of the top plants identified by the study.
Buttercups and lesser celandine (Ranunculus species and Ficaria verna)
Buttercups (Ranunculus species) and lesser celandine (Ficaria verna) are welcome sights of early and late spring providing carpets of attractive yellow flowers for an early food source for pollinators. This group of plants were found to be the most frequently visited throughout spring, and were used by bumblebees, honeybees, solitary bees, and hoverflies. The hoverfly Cheilosia albitarsis s.l lays its eggs in the rootstocks of buttercups and adults can often be seen feeding on pollen and nectar from the flowers. Reduce the frequency of mowing to encourage growth of lesser celandine and creeping buttercup in lawns, or mow around patches. Meadow buttercup can be encouraged in tall grass if left to grow.
Dandelion (Taraxacum officinale)
Although they are often seen as a weed, dandelions, Taraxacum officinale, provide an important source of nectar and pollen for flying insects. Growing in a wide variety of habitats, including meadows, waste land and roadside verges, dandelions provide a bright springtime display. Embrace dandelion flowers in your lawn by reducing the frequency of mowing, mowing a little higher, or simply allowing flowering in between cuts. Doing so will provide an essential nectar source for the insects in your garden, in turn benefitting the pollination of your vegetables and garden plants. If you’re worried about the seeds spreading to your flower beds, you could even dead-head them. In this study, dandelions were visited by hoverflies and bumblebees but contributed more to the diet of honeybees and solitary bees in spring.
Geum
Geum is a genus of hardy rhizomatous herbaceous perennials, commonly known as avens, which produce loose clusters of saucer shaped flowers, usually yellow, red, or orange, from late spring to summer, held above rosettes of semi-evergreen foliage. Avens were visited by bumblebees, honeybees and hoverflies in this study but were found to be particularly popular with solitary bees in late spring. In general, plants should be grown in moist but well-drained soil in full sun to partial shade. One popular species is water avens, Geum rivale, which is native to the UK. This moisture-loving herbaceous-perennial has bright green basal leaves and pale orange flowers which are produced from late spring to midsummer. Water avens thrives in rich, moisture retentive soils positioned in full sun to partial shade. A large variety of cultivars are available but be careful to choose those with single as opposed to double flowers which are of little benefit to pollinators.
Thistles, Knapweeds and Cat’s ear (Cirsium/Centaurea/Hypochaeris species)
Thistles (Cirsium arvense, C. vulgare, C. palustre), knapweeds (Centaurea nigra) and cat’s ear (Hypochaeris radicata) are common meadow plants, providing valuable forage during the summer due to the high volumes of nectar and pollen they produce. This group of plants was found to be one of the most frequently visited throughout the study, being used by bumblebees, honeybees, solitary bees, and hoverflies. Overall, bees were found to use Cirsium/Centaurea/Hypochaeris more frequently than hoverflies. These plants can be encouraged by creating a mini meadow in your garden, achieved through reducing the fertility of soil by repeated mowing and removal of cuttings. Alternatively, there are many popular ornamental Cirsium and Centaurea that can be used to attract pollinators, for example melancholy thistle (Cirsium heterophyllum), plume thistle (Cirsium rivulare), perennial cornflower (Centaurea montana) and cornflower (Centaurea cyana).
Bramble (Rubus fruticosus)
Bramble is a very hardy plant which will grow pretty much anywhere and can take over your garden if not controlled. This means many gardeners see this plant as a nuisance, unaware of its importance to wildlife, providing an essential nectar and pollen source for many insects due to its long flowering period. Bramble was found to be the most frequently visited plant across all groups sampled in this study (bumblebees, honeybees, solitary bees, and hoverflies), used from late spring to early autumn. Non-native ornamental species of Rubus are often invasive so stick to native fruit bushes such as blackberry, raspberry, loganberry, and tayberry for variety.
Bidens/Coreopsis
Bidens and Coreopsis are garden plants in the daisy family. Often yellow or white in colour, they flower during summer and autumn, extending the flowering season for pollinators. In this study, Bidens/Coreopsis were visited frequently by solitary bees, bumblebees, and hoverflies. Species popular with gardeners include Bidens aurea (pictured) and Coreopsis verticillata, both which are easily grown in well-drained soil.
Rudbeckia/Helenium
Rudbeckia and Helenium are both sun-loving members of the daisy family, flowering from summer to mid-autumn. Both are easy to grow, and perform best in moist, well-drained soils in full sun. The flowers of perennial Rudbeckia are generally yellow, but there are also annual varieties that come in a wider range of colours. Helenium are perennials that produce flowers in various shades of yellow, orange and red. Hoverflies and solitary bees were the pollinators found to visit Rudbeckia/Helenium plants most frequently in this study.
Angelica/Heracleum
Wild angelica (Angelica sylvestris) and hogweed (Heracleum sphondylium) are a common sight in meadows and hedgerows through the summer. These native members of the carrot family have clusters of tiny white flowers which are often seen to be covered in a variety of insects. This study identified that wild angelica and hogweed were one of the favoured plants of hoverflies across the whole season. Whilst these plants were still visited by honeybees, bumblebees, and solitary bees, they were used by this group significantly less than the hoverflies. Wild angelica and hogweed can be encouraged in wild sections of gardens, hedgerows, and meadows by reducing the frequency of mowing. Alternatively, Angelica gigas and Angelica archangelica may be planted as horticultural alternatives.
Michaelmas daisies (Aster/Symphyotrichum spp.)
Asters are a group of plants within the daisy family that come in shades of purple and pink, with many species commonly known as Michaelmas daisies. Flowering from late summer through to October, asters provide pollinators with a food source when many native plants have finished flowering. These are shade-tolerant plants, which can be grown in most soil providing some moisture is retained. Asters were found to be visited by hoverflies, honeybees and bumblebees in the summer and were a particular favourite for bumblebees in the autumn. Our results include Symphyotrichum species which have been recently reclassified from Aster.
Clematis
Clematis are popular garden climbers which come in a variety of colours. The flowers can be enjoyed throughout the year depending on the species grown, with spring, summer, autumn, and winter varieties available. In this study, Clematis were found to be visited predominately by bumblebees, honeybees, and hoverflies in the autumn. There are hundreds of colourful varieties to choose from which will flower into September, examples include varieties ‘Jackmanii’ and ‘Kermesina’.
If you want to add these plants to your garden, head to Y Pot Blodyn garden centre. Look for plants displaying our Saving Pollinators logo to ensure they are grown in peat-free soil without the use of synthetic insecticides.