Is your garden bee-friendly?
On average, our gardens provide far more flowers than agricultural land and although large fields of flowering rape may be attractive to bees, they are often sprayed with toxic insecticides. Unfortunately, many of our gardens are populated with intensively bred bedding plants, most of which have little or no nectar, and so are of no interest to bees. Pansies, petunias, busy-lizzies and begonias add a splash of colour, but years of selection for increasingly showy blooms have resulted in the flowers losing their original function (to attract pollinating insects). To encourage bees and other pollinating insects, it is far better to grow old-fashioned cottage garden perennials such as lavender, lupins, Aquilegia and sage, together with foxgloves, native bluebells and other wild flowers like viper’s bugloss, comfrey, sainfoin, tufted vetch, bird’s foot trefoil, teasel and knapweed.
The large queen bumblebees and solitary bees that live in our gardens, come out of hibernation as early as February, when they need to feed on nectar from early wildflowers such as lungwort, dandelion, daisy and celandine. You can see three male, amorous, hairy-footed flower bees chasing a female, as she feeds on lungwort, in the picture on the left. Other essential sources of nectar and pollen in the spring are the blossom of fruit trees and bushes. It's a good idea to leave a few brassica plants to flower as they will provide abundant nectar in early spring.
Bumblebees fly low over the ground searching for undisturbed nest sites. Some species prefer to nest underground in abandoned burrows of rodents, while others prefer to nest just above the ground in dense grass or leaf-litter. The queen stocks her nest with pollen and nectar, and lays her first batch of eggs. This means that you should leave part of the soil undisturbed and not cut your grass below 10-15 cm to protect these nesting sites.
Look for underground bumblebee nesting sites in bare earth.
Female bumblebees incubate their eggs much as a bird would, by sitting on them while shivering her flight muscles to produce warmth. When the eggs hatch the legless grubs consume pollen and nectar, grow rapidly, and pupate after a few weeks. A few days later the first workers hatch from their pupae and begin helping their mother, expanding the nest and gathering food. By mid-summer, nests can contain several hundred workers who must feed on nectar and pollen-rich flowering herbs, such as rosemary, lavender, marjoram, chives, sage, verbena, borage and comfrey. The picture below shows a worker bumblebee foraging in summer flowering marjoram.
At this point the queen starts laying both male and female eggs: the females are fattened up to become future queens. When they are adult, both males and new queens leave the nest, mate, and the new queens burrow into the ground to wait until the following spring. The males, workers, and the old queen die off in the autumn, leaving the nest to decay.
Bumblebees without pollen baskets on their hind legs are probably cuckoo bumblebees. These bees have switched to a parasitic existence. The females are especially powerful and force their way into the nests of their bumblebee hosts. They kill or evict the queen and take over her workers as their own, using them to rear their own offspring.
Some species of solitary bee continue to feed and provision nests well into the autumn. When completed, the nests are sealed with a plug of mud or leaf mixture. The old queen, workers, males and all the adult solitary bees do not live to see the next generation.
In autumn the number of flowers begins to decrease, but a ready and continuous supply of pollen and nectar are still being sought by bees until late in the year. Suitable flowers for this time of year are verbena, aster, black-eyed susan, winter- flowering honeysuckle and ivy. Careful pruning can increase the length of flowering or even delay the start of flowering till later. Look for gaps in flowering and try to find a plant that will fill that gap for the next year. Leave dead stems on plants in the border over winter as they may provide homes and shelter for many insects including some bees.
Gardeners can help bumblebees by leaving suitable places for hibernation undisturbed, such as a cool, north facing bank which they can burrow into. Nest sites of solitary bees (in the ground, in borders and the lawn, and in wood and in plant stems) should be left undisturbed through the winter. It can be useful to mark the site of spring and summer ground nests as they can easily be forgotten about when forking over soil. Where nests occur in bare ground the area should be kept relatively free of ground covering plants.
Here is a white-tailed bumblebee feeding on nectar from ivy flowers, just prior to winter hibernation.
Are there sufficient bee-friendly flowers that can provide a continuous source of nectar, between February and October, in your garden, plus undisturbed spaces where bumblebees and solitary bees can nest?
If you would like your garden to be included in the Bee Foraging Corridor, between Marlborough and Pewsey, please download and fill in this Bee-Friendly Garden form, then send it to firstname.lastname@example.org