The Bee and the Damson Tree

23 March 2016 // On Nature

Osmia cornuta close Horned mason bees shortly after emerging from the bundle of hollow elder twigs. Photo: Andreas Groeger

Words: Katherine Price

After a wet mild winter like this one, it’ll be hard to say when spring is really here. So many signs, those precious iterations. By contrast there’s a place I know where spring arrives definitively on one particular day. One day it’s winter. The next it’s spring.

This place is a second storey balcony in the German city of Munich. A white rendered apartment block from the 1920s in a grid of similar blocks where street trees are rare. The balcony on the western elevation is a bare exposed platform two metres square, ten metres above the street, entirely isolated from the rest of the world. But what happens when spring arrives on the balcony is a bewitching reminder of interconnectedness of things.

Landlocked Munich – about as far from the temperate influence of the sea as you can be in Western Europe – hangs on to winter until the last minute. There are still signs, a kind of easing. The acid yellow furze of cornelian cherry flowers. The pounding turquoise waters of the River Isar, milky with sediment from the snow melting through the alpine screes sixty miles to the south. Lords and ladies foliage shiny and dark as spinach unfurling in the leaf litter under the trees of the Englischer Garten. And above all, the song and argie-bargie of the birds. Humans feel the changes too. We are part of the natural world, however much we try to shake it off. On the first mild day of the year the base of the southern wall of the Residenz – the palace in the centre of the city – and the ranks of south facing chairs outside the chic cafes are rammed with people wearing shades, basking like seals, lifting their faces towards the sun.

On the balcony though, it’s still winter. In a matter of weeks, when summer comes with its sledgehammer heat and electric storms, the spiny grapefruit tree, the agave, the shiny stiff-leaved hibiscus will be moved outside in their heavy terracotta pots. The spiky velvet-coated tillandsias go out too, hung from the white painted metal railings to catch the sun and the rain and the air. The houseleeks will swell and flush green, the little irises from the near east will put up their complex purple flowers on stubby stems. The swifts will scream as they wheel like cut throat razors along the ersatz gorge of the street in the sultry evenings. There’s just enough room for a table and two chairs and on sweltering nights the balcony becomes a cool crows nest for watching the stars, constellations sliding across the long rectangle of sky between the buildings.

But for now, it’s winter on the balcony. Not even moss or algae find purchase on the surfaces that are swept clean by the bitter desiccating winds. There’s a stack of plastic flower pots on one side of the French Windows and on the other, several bundles of foot long elder twigs tied together with string, and laid horizontally in a pile.

Ten metres below, the land between the apartment blocks lies sealed and thwarted under paving and tarmac, all but a strip of vegetation at the base of the building, a gritty patch of moss, chickweed, grasses, daisy and hawkweed rosettes, bound by a dark barberry hedge to waist height. About twenty metres from the balcony, growing on the scruffy grass in a container made of ugly composite slabs of grey pebbles, is a small damson tree.

In the time I’ve known this tree – eight years now – its blooming time has fluctuated with the harshness of the season. Sometimes the end of February, sometimes weeks later. It never fails to flower, though, and it does it magnificently. Billowing drifts of white blossom coat its angled limbs and shade the rings on its pewter trunk. Even against the gloopy white render of the wall behind it, in the banal monotony of the car lined street, it is spectacular.

But here’s the thing. The very day the flowers open on the damson tree below, something changes on the balcony. Suddenly there is life, movement, sound, a whole different texture to the atmosphere. The bees have broken out of their cells.

These are mason bees – and on this particular balcony they are horned mason bees, Osmia cornuta, that aren’t seen in the UK, though other mason bee species are. Mason bees are solitary bees. They don’t do honey or beeswax. The first to hatch from their cocoons in the dry hollow core of the elder twigs are the males. They hang around the bundles until the females emerge, then they mate and die.

But for the females, this is just the start. They fly from the balcony straight into the clouds of blossom on the damson tree. They gather pollen and nectar to create food stores in the nests they make in the same hollow twigs that they emerged from for the first time in their lives just a few hours before. Collecting enough food to support a single offspring takes many trips to the damson tree. When the sticky ball of pollen and nectar is large enough, the bee backs into the hole and lays an egg on top of it. Then she builds a partition, creating a new cell. She repeats the process, flying back and forth, back and forth to the damson tree, until she has filled the hollow tube with a series of eggs, each with its own carefully weighed food supply, finally plugging the opening with a mud like seal.

The lifecycle of these mason bees is fascinating and amazing and there are plenty of people who know much more than me. And anyway, that’s not my story. I could tell you that they are far more efficient pollinators of fruit trees than honey bees, that the farmers are eyeing them up as future collaborators but that’s not my point.

There is something deeply touching about their utter disregard for the human dimension, these small creatures going about their lives as if a bleak extrusion high up on a concrete slab in a major city were the most natural place in the world.

But the thing most wonderful to me is the exquisite correlation of the bee and the damson tree.

One day it’s winter and the next it’s spring.

Katherine Price on Caught by the River

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