The Hague stands with one foot in the dunes and one in the woods, and the two sides of the city produce different complaints. To the west lie the Westduinpark, Meijendel and the Scheveningse Bosjes: dune landscape with marram grass, sea buckthorn and reed. To the east stands the Haagse Bos with old beech and oak, and beyond it the estates towards Wassenaar and Voorburg, where alder and birch do well in the damper ground.
The sea is not a detail here. Under an onshore wind — the default in the Netherlands — the air arriving over the city has spent hundreds of kilometres over water and carries almost no pollen. Coastal concentrations are therefore structurally lower than ten kilometres inland. The switch comes with an easterly: the same spot turns within a day from one of the quietest places in the Randstad into one of the busier ones, because pollen then arrives from inland and from across the border. For the grass season in May and June that means one habit is worth forming: read the wind alongside the level.