Hardwood decking is a more expensive option than softwood, which has a closer grain and less knots. These both offer extra durability and less maintenance.
Close natural alternative to hardwoods include thermowoods, like Lunawood®, which are often chosen as these woods have been thermally modified to enhance the chemical, and physical properties of the timber, particularly for durability. Thermowood is produced by heat treating selected timbers, such as; Scandinavian Redwood (Pinus sylvestris).
Hardwoods can often have more of a diverse grain pattern and natural colouring than softwoods do. Fixings would usually be stainless steel screws through the boards.