Any crack in the wall or pavement can be used, right? Some plants really don't need much. They drop their seeds somewhere, grow fast and the next season they will grow somewhere else.
Nikon D5500 + Sigma 105 (f/9, 1/1250, 175mm, ISO400)
This is Euphorbia. A pretty common weed that has very cute apple-shaped seedpods.
Nikon D5500 + Sigma 105 (f/9, 1/800, 105mm, ISO1600)