WITH spring finally upon us, many gardeners will be busy weeding, sowing seeds and tending to batches of seedlings. In the bumblebee world, it is the time of year when the queen emerges from hibernation to start a new nest.
Given that bumblebees help to pollinate around 80 per cent of our crops – including raspberries, beans and peas – these familiar and much-loved insects are of paramount importance to our gardens and farms.
However, in the last 80 years two species have become extinct in the UK and several more are endangered due to changes in farming methods which have led to the loss of 97 per cent of flower-rich grasslands. One species, the great yellow bumblebee, can only be found on the north coast and some islands of Scotland.
Now garden owners, along with farmers, landowners, businesses and local authorities, are being asked to help save the UK’s remaining 24 species.
The Bumblebee Conservation Trust (BBCT), which was set up in 2006 in response to growing concerns about the plight of the bumblebee, believes the country’s gardeners have a key role to play in reversing the diminishing numbers.
Whether you have a window box, allotment or large garden, you can do your bit to boost your local bumblebee population simply by planting bee-friendly flowers.
“The UK used to be covered in wild flower areas,” says Anthony McCluskey, outreach officer at the BBCT, which is based at the University of Stirling. “We would have had meadows with wild flowers perfect for bees. Now there is hardly anything that is perfect for bees.”
The trust has drawn up a list of plants and flowers rich in nectar (a source of fuel) and pollen (to provide the protein and nutrients needed for growth), which are in bloom during the active phase of the bees’ lifecycle from spring until late summer.
Forget ornamental plants such as pansies and begonias which have been cultivated to produce showy blooms but provide little pollen or nectar, and opt instead for flowers such as foxgloves, geraniums and wild roses which are a rich source of food for bees.
Plants which have a habit of escaping into the wild, such as rhododendron, should also be avoided.
On the list are sunflowers and marjoram which have open flowers accessible to short-tongued bumblebees, and honeysuckle which attracts the long-tongued species.
Ideally, gardeners should aim to have at least two different bee-friendly plants for each flowering period.
McCluskey says: “At this time of year, towards the end of March, it’s important to remember the queens will be emerging. They will have been hibernating all winter. They will be quite hungry.
“It’s vital to have food for every season. If bees are without food for a long time, whole colonies can die out.”
In spring, you can choose from the aromatic green shrub rosemary or winter heather if you have dry soil, lungwort or hellebore for shady areas, pieris for acid soil or chives which can grow in any soil.
Alternatively, pussy willow is a great source of pollen and nectar for queens, while flowering currant is popular with a range of species and comfrey ideal for long-tongued bees.
When the queen bee emerges from the soil following a winter of hibernation, she first has to build up her energy reserves by drinking the nectar from flowers. Her next job is to find a suitable nest site to rear her first batch of eggs – a group of female workers tasked with feeding and nurturing the colony.
While the queen remains in the nest producing more offspring throughout the summer, the worker bees will be kept busy stocking up on pollen and nectar to feed up to 400 individuals.
During this season, to help ensure a new generation of bumblebees will return the following year, thyme can be planted in a sunny spot with well drained soil, while alliums, blackberries and globe thistles are able to tolerate poor soil conditions.
Long-tongued bees will love the flowers of aquilegia or monkshood and small-flowered varieties of sweet peas are ideal for most species.
As the year progresses the queen will produce new queens and males to allow the colony to reproduce.
After mating, the males will die off along with the old queen and worker bees, leaving the new queens to stock up on pollen and nectar before hibernating underground.
Autumn is the time when the male bees need plenty of energy to allow them to find a mate, while for the queens, an abundance of food is vital in order for them to survive the winter months.
Lavender, catmint and hebe are all much loved by bumblebees, while honeysuckle will provide food for the long-tongued species and cosmos will attract short-tongued bees.
In addition to planting pollen and nectar-rich plants, gardeners are advised not to use pesticides and herbicides and to try natural alternatives such as companion planting instead. They can also help by participating in the BBCT’s Bee Watch survey, which involves taking photographs of bumblebees – not to be confused with their cousins the honeybee and solitary bee – and sending them in to the trust’s website.
“We then get back to the user and let them know what species it is,” says McCluskey.
“This also helps us to create maps of the distribution of various species and over time we’ll be able to detect any changes in these populations.”
Gardeners with an established garden can check the website to see how bee-friendly their existing plants are.
The Bee Kind tool gives people a score depending on how many suitable plants they grow and gives advice on other flowers to plant.
They can then add their score to a map to allow the trust to plot bee-friendly gardens across the country.
As well as conservation work, the BBCT runs outreach events to raise public awareness of the bumblebee, including visits to schools and guided walks and talks throughout the year.
Today the trust is holding a bumblebee identification day at the Royal Botanic Gardens Edinburgh between 10am and 3pm. A similar event will be held at Stirling University tomorrow.
• For more information about the work of the trust and bumblebees visit www.bumblebeeconservation.org