May 20th is World Bee Day. It is intended to remind us how important honey bees and their wild relatives are for nature and, last but not least, our food supply. Each of us can help to support bees threatened by habitat loss and pesticides – for example by offering them food and nesting places in the garden and on the balcony. However, there are a few things to keep in mind.
Bees are one of the most important pollinating insects on our planet: Around 75 percent of the food plants used by humans, but also countless wild plants depend on these insects for their reproduction. However, not only the honey bees are involved, but also more than 20,000 wild bee species. In Germany alone there are around 595 such wild bees. Unlike honey bees, many of their wild relatives do not live in complex colonies, but solitary. They often make their nests singly in the ground, in plant matter, and other sheltered places.
But like the honey bees, the wild bees don’t have it easy either: The loss of plant biodiversity in the field, the use of pesticides in agriculture and the concrete of the landscape are affecting them. As a result, the bees can no longer find enough food and places to lay their eggs, they are attacked by parasites and viruses or even poisoned directly by the pesticides. The annual World Bee Day, scheduled for May 20th, aims to raise awareness of the importance and threats to bees and thus help to protect these important insects.
Lining: Long grass islands and diverse flowering plants
You can also contribute to the preservation of the hard-working pollinators in your own garden and even on the small city balcony. However, there are a few points to bear in mind. One of them: The lawn in the garden must not be too short. “A lawn that is only allowed to grow a few centimeters has no food plants to offer wild bees. But if you only mow once or twice a year – namely in early summer after the main flowering of the first plants and after the growing season in September – you give many flowering plants the opportunity to flower and do something good for many insects,” explains Manuel Hensen, coordinator of the Wild bee projects of the German Wildlife Foundation. That’s not to say a wild bee-friendly garden has to look messy. It is enough to simply leave a few small islands of plants when mowing the lawn.
A variety of plants is also important, which ensures that the bees always find something flowering depending on their food preferences and season. Many native flowering plants can be used as a source of nectar and pollen for wild bees. “It doesn’t always have to be just flowers. Native trees and shrubs, such as hawthorn, sloe, willow or fruit trees of all kinds, are also attractive to wild bees in a garden and are used by them as a source of nectar and pollen, especially in spring,” explains Hensen. The following applies to the balcony: plant native wild perennials such as dyer’s chamomile or yarrow in the pots.
Nest sites: open spots and sunny bee hotels
If you want to offer wild bees the opportunity to create nests and lay eggs, you should offer open ground areas in the garden. Because there is only dense grass everywhere and flower beds are covered with bark mulch, wild bees hardly find a way to create nesting sites in the ground. Much better are sunny lawns that are kept open and sandy in some places. Many wild bee species dig nest tubes here and place their brood cells in them. “You can also create an area of sand or a pile of sand. An area of four square meters or more is sufficient for this. The sand should be 20 to 30 centimeters high. To prevent plants from growing through, first remove the topsoil to a depth of about 20 centimeters,” says Hensen.
There are also a few things to consider when it comes to the popular wild bee hotels. So you should hang up the nesting aids in a dry, warm, sunny and wind-protected location. A south-easterly position is best. Bee hotels in trees or freely hanging, shaded nesting aids, on the other hand, are not accepted by the insects. The filling should also be suitable, drill holes in the wood or hollow bamboo sticks are good. “Unfortunately, wild bee hotels are often offered in DIY stores, which are of almost no value to the animals,” says Hensen. For example, wood wool, pine cones or pebbles are completely useless.
Source: German Wildlife Foundation