How do you damp proof garden wall?

To damp proof a garden wall, start by applying a waterproofing sealant or damp-proofing membrane to the exterior surface. Ensure proper drainage by grading the soil away from the wall and installing a French drain if necessary. Additionally, consider using a breathable render or paint that allows moisture to escape while preventing water ingress. Regular maintenance, such as checking for cracks and repointing, will also help keep the wall dry.