About 75% of wild bees, and of course many other insect species such as digger wasps and sand wasps, nest in the soil and often the entire development cycle occurs there, in the holes and tubes where the brood lives.
If you want to support soil-dwelling species, like this "trouser bee" in the cover photo above, you can create a sand bed, or sandarium in new German, in your garden. With a bit of luck and if the location is protected against rain from above, even the ant lion will move into your new bed. He has developed a unique method to get prey. He lurks in the sand until an animal falls into his self-made funnel.
Ant lion hunting ground
Wild bees live solitaryThese wild bee species that live solitarily, i.e. not in a 'hive' like our honey bee, are more vulnerable in their survival than the honey bee, which after all has the advantage of being the beekeeper's favorite pet.
...and are also very special.The fact is that most wild bees, unlike the honey bee, are very selective in what they accept as food. Almost all species are more or less oligolectic, i.e. they need a specific plant species or plant family from which they 'harvest' food and nesting material for their brood. If they do not find this plant species, they lack a livelihood. Conversely, plants are also often dependent on pollination by the specific wild bee species.
This is how the plant worksHere it goes however now primarily around a practical guidance for the planting of such a sand bed, a contribution to the wild bees in the special one comes later still.
The place for the ground nesting aid should be on the one hand fully in the sun, but on the other hand also protected from driving rain. In such a place, you dig a trough about 60 cm deep, the area should be at least 40 x 40 cm, the larger the better.
You can frame the whole thing with the help of deadwood logs, this has, besides the visually decorative effect, the advantage that at the same time there is building material that can be used by the bees to close the brood tubes. Then fill the trough with unwashed 0/2 sand. Also loess, a very fine, silty material, if available in your area, is a perfect substrate for the wild bees to create brood tubes.
If your garden is located in an area with sandy soil anyway, so you live in Brandenburg, for example, simply choose a suitable spot that you keep free of overgrowth.
Without food supply it does not workIt is important that there are also food plants near the nesting aid; wild bees have a rather narrow radius of action, i.e. the nesting site, where the breeding tubes are created, and the food site or 'material store' for expanding and closing the tubes, must be close together. The radius of solitary wild bees is between 70 and 400 meters. The honey bee is much more flexible. It can fly up to 5 km to provide itself with nectar and pollen.
So if you want to create a food supply for the mini flyers, plant perennials from the list of lean plants in the near vicinity (Link)
And one more advantage of sandy hollows. Birds also love them as a "bathing place" to rid their feathers of parasites.