Dry stone walls, and old stone walls held together with mortar, acquire a flora of resilient species that thrive in their damp crevices. In Weardale these vertical gardens are at their best from mid-May to early June, before conditions become too dry.
This beautiful display, with yellow Alyssum saxatile in the foreground, cascades down a wall in Stanhope, Weardale
Fairy foxglove Erinus alpinus covers large areas of old walls in Stanhope.
Ferns colonise walls too, but usually on the side that's shaded from the sun. This is brittle bladder fern Cystopteris fragilis, growing in the wall around St. John's Chapel churchyard in Weardale.
Wall rue Asplenium ruta-muraria and maidenhair spleenwort Asplenium trichomanes sharing the same crevice in a wall at Eggleston in Teesdale
Aubretia and dandelions in a retaining wall near Daddry Shield in Weardale.
Yellow Alyssum saxatile clinging to the narrowest of crevices in Stanhope.
Wallflower Cheiranthus cheiri, living up to its name in Stanhope.
Fairy foxglove Erinus alpinus, on a wall in Stanhope.
Snow-in-summer Cerastium tomentosum on a wall in Stanhope.