I always find it cheering that the hard edges of London are softened by the proliferation of the humble little plants that get called weeds (aka wildflowers). For example a fine display of Nipplewort (Lapsana communis) has appeared in the cracks and gaps between the front garden's low wall and the slabs of the pavement. Apparently the common name of L. communis derived from the belief that it can cure sore nipples- though I'm not sure how!