After foundation of the Wadden Sea National Park of Schleswig-Holstein in 1985, grazing and drainage of salt marshes was reduced. In 10 priority areas, coastal protection measures were stopped. Since 1988, salt marsh vegetation is mapped every 5 years in the framework of a trilateral monitoring programme. Salt marsh area increased between 1988 and 2006 more on the mainland than on islands and Halligen. Marshes in the priority areas exhibited an above-average increase close to the Elbe estuary, while they decreased slightly in Northern Frisia. These monitoring results show that maintenance of brushwood groynes can be adapted to hydrodynamic conditions and can be discontinued in individual areas with high sedimentation rates. Of the total area of 12,450 ha in 2006, 47 % of the salt marshes were ungrazed, 11 % moderately grazed and 38 % intensively grazed. In ungrazed marshes, the Atriplex portulacoides type and Elymus athericus type increased, whereas the Puccinellia maritima type and the Festuca rubra type decreased. The number of vegetation types increased under all grazing regimes. The high marsh increased at the expense of the low marsh. Since the pioneer zone remained of the same extent, no imminent risk of 'ageing' of salt marshes can be detected.