Wood- clean with a pressure washer or stiff brush and water; apply wood preserver to non-treated softwoods, and apply, if desired, teak oil to hardwoods once a year to keep their colour.
Cast iron- clean with a damp cloth. It rusts slowly when exposed to air. You will need to sand down (or use a wire brush/wire wool) damaged areas and apply a rust converter, followed by an undercoat and topcoat of paint.
Aluminium- wipe down with a damp cloth, and oil all fittings and moving parts.
Plastic and resin- clean with a damp cloth and detergent, or with a proprietary spray cleaner.
Stone- clean with a pressure washer or stiff brush and soapy water.
Upholstery- use a proprietary liquid or spray for cleaning.
Source: ‘Short Cuts to Great Gardens’- Reader’s Digest 1999
Old School Gardener